From fc56f4bef4234b03eb411a6dbc2acb9c546f0815 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Tue, 16 Dec 2025 15:31:29 +0100
Subject: [PATCH 01/12] Add support for 1, 0 and YES, NO boolean strings in
 EnvironementVariablesProvider

---
 .../EnvironmentVariablesProvider.swift        | 21 +++++-
 .../ConfigBoolsFromStringDecoder.swift        | 64 +++++++++++++++++++
 .../ConfigBoolsFromStringDecoderTests.swift   | 45 +++++++++++++
 .../EnvironmentVariablesProviderTests.swift   | 39 ++++++++++-
 4 files changed, 164 insertions(+), 5 deletions(-)
 create mode 100644 Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
 create mode 100644 Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift

diff --git a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
index 1608823..013629c 100644
--- a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
+++ b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
@@ -142,6 +142,9 @@ public struct EnvironmentVariablesProvider: Sendable {
 
         /// A decoder of arrays from a string.
         var arrayDecoder: EnvironmentValueArrayDecoder
+
+        /// A decoder of bool values from a string
+        let boolDecoder: BoolDecoder
     }
 
     /// The underlying snapshot of the provider.
@@ -165,16 +168,19 @@ public struct EnvironmentVariablesProvider: Sendable {
     /// - Parameters:
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
+    ///   - boolDecoder: The decoder used for converting string values to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     public init(
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
+        boolDecoder: BoolDecoder = .allBooleanStrings,
         arraySeparator: Character = ","
     ) {
         self.init(
             environmentVariables: ProcessInfo.processInfo.environment,
             secretsSpecifier: secretsSpecifier,
             bytesDecoder: bytesDecoder,
+            boolDecoder: boolDecoder,
             arraySeparator: arraySeparator
         )
     }
@@ -200,11 +206,13 @@ public struct EnvironmentVariablesProvider: Sendable {
     ///   - environmentVariables: A dictionary of environment variable names and values.
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
+    ///   - boolDecoder: The decoder used for converting string to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     public init(
         environmentVariables: [String: String],
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
+        boolDecoder: BoolDecoder = .allBooleanStrings,
         arraySeparator: Character = ","
     ) {
         let tuples: [(String, EnvironmentValue)] = environmentVariables.map { key, value in
@@ -219,7 +227,8 @@ public struct EnvironmentVariablesProvider: Sendable {
         self._snapshot = .init(
             environmentVariables: Dictionary(uniqueKeysWithValues: tuples),
             bytesDecoder: bytesDecoder,
-            arrayDecoder: EnvironmentValueArrayDecoder(separator: arraySeparator)
+            arrayDecoder: EnvironmentValueArrayDecoder(separator: arraySeparator),
+            boolDecoder: boolDecoder
         )
     }
 
@@ -245,6 +254,7 @@ public struct EnvironmentVariablesProvider: Sendable {
     ///     - When `true`, if the file is missing, treats it as empty. Malformed files still throw an error.
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
+    ///   - boolDecoder: The decoder used for converting string values to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     /// - Throws: If the file is malformed, or if missing when allowMissing is `false`.
     public init(
@@ -252,6 +262,7 @@ public struct EnvironmentVariablesProvider: Sendable {
         allowMissing: Bool = false,
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
+        boolDecoder: BoolDecoder = .allBooleanStrings,
         arraySeparator: Character = ","
     ) async throws {
         try await self.init(
@@ -260,6 +271,7 @@ public struct EnvironmentVariablesProvider: Sendable {
             fileSystem: LocalCommonProviderFileSystem(),
             secretsSpecifier: secretsSpecifier,
             bytesDecoder: bytesDecoder,
+            boolDecoder: boolDecoder,
             arraySeparator: arraySeparator
         )
     }
@@ -273,6 +285,7 @@ public struct EnvironmentVariablesProvider: Sendable {
     ///   - fileSystem: The file system implementation to use.
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
+    ///   - boolDecoder: The decoder used for converting string values to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     /// - Throws: If the file is malformed, or if missing when allowMissing is `false`.
     internal init(
@@ -281,6 +294,7 @@ public struct EnvironmentVariablesProvider: Sendable {
         fileSystem: some CommonProviderFileSystem,
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
+        boolDecoder: BoolDecoder = .allBooleanStrings,
         arraySeparator: Character = ","
     ) async throws {
         let loadedData = try await fileSystem.fileContents(atPath: environmentFilePath)
@@ -297,6 +311,7 @@ public struct EnvironmentVariablesProvider: Sendable {
             environmentVariables: EnvironmentFileParser.parsed(contents),
             secretsSpecifier: secretsSpecifier,
             bytesDecoder: bytesDecoder,
+            boolDecoder: boolDecoder,
             arraySeparator: arraySeparator
         )
     }
@@ -393,7 +408,7 @@ extension EnvironmentVariablesProvider.Snapshot {
             }
             content = .double(doubleValue)
         case .bool:
-            guard let boolValue = Bool(stringValue) else {
+            guard let boolValue = boolDecoder.decodeBool(from: stringValue) else {
                 try throwMismatch()
             }
             content = .bool(boolValue)
@@ -426,7 +441,7 @@ extension EnvironmentVariablesProvider.Snapshot {
         case .boolArray:
             let arrayValue = arrayDecoder.decode(stringValue)
             let boolArray = try arrayValue.map { stringValue in
-                guard let boolValue = Bool(stringValue) else {
+                guard let boolValue = boolDecoder.decodeBool(from: stringValue) else {
                     try throwMismatch()
                 }
                 return boolValue
diff --git a/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift b/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
new file mode 100644
index 0000000..6d92e6f
--- /dev/null
+++ b/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftConfiguration open source project
+//
+// Copyright (c) 2025 Apple Inc. and the SwiftConfiguration project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftConfiguration project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#if canImport(FoundationEssentials)
+import FoundationEssentials
+#else
+import Foundation
+#endif
+
+/// A decoder that converts a boolean string into a Bool, taking into account different boolean string pairs.
+///
+/// This decoder is able to convert a string to Bool values when the string’s Boolean value format is 0 or 1, true or false, or yes or no.
+/// Boolean strings taken into account when decoding are configurable at init time only.
+///
+/// ## Boolean values
+///
+/// By default, following boolean string pairs are decoded to a Bool value: trueFalse (true, false), oneZero (1, 0), yesNo (yes, no).
+/// Decoding is case-insensitive.
+@available(Configuration 1.0, *)
+public struct BoolDecoder: Sendable {
+
+    public enum BooleanString: Sendable { case trueFalse, oneZero, yesNo }
+
+    public static var allBooleanStrings: Self { .init(booleanStrings: [.trueFalse, .oneZero, .yesNo]) }
+
+    private let booleanStrings: [BooleanString]
+
+    public init(booleanStrings: [BooleanString]) {
+        self.booleanStrings = booleanStrings
+    }
+
+    func decodeBool(from string: String) -> Bool? {
+        for semantic in self.booleanStrings {
+            switch semantic {
+            case .trueFalse:
+                let stringLowercased = string.lowercased()
+                if ["true", "false"].contains(stringLowercased) {
+                    return stringLowercased == "true"
+                }
+            case .oneZero:
+                if ["1", "0"].contains(string) {
+                    return string == "1"
+                }
+            case .yesNo:
+                let stringLowercased = string.lowercased()
+                if ["yes", "no"].contains(stringLowercased) {
+                    return stringLowercased == "yes"
+                }
+            }
+        }
+        return nil
+    }
+}
diff --git a/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift b/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
new file mode 100644
index 0000000..70bcb92
--- /dev/null
+++ b/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftConfiguration open source project
+//
+// Copyright (c) 2025 Apple Inc. and the SwiftConfiguration project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftConfiguration project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Testing
+import Foundation
+@testable import Configuration
+
+struct ConfigBoolsFromStringDecoderTests {
+
+    @available(Configuration 1.0, *)
+    @Test("boolDecoder, all boolean strings enabled")
+    func boolDecoderAllBooleanStringsEnabled() throws {
+        let bd = BoolDecoder(booleanStrings: [.oneZero, .trueFalse, .yesNo])
+        #expect(bd.decodeBool(from: "1") == true)
+        #expect(bd.decodeBool(from: "0") == false)
+        #expect(["Yes", "yes", "YES", "yES"].allSatisfy { bd.decodeBool(from: $0) == true })
+        #expect(["No", "no", "NO", "nO"].allSatisfy { bd.decodeBool(from: $0) == false })
+        #expect(["true", "TRUE", "trUe"].allSatisfy { bd.decodeBool(from: $0) == true })
+        #expect(["false", "FALSE", "faLse"].allSatisfy { bd.decodeBool(from: $0) == false })
+        #expect(["_true_", "_false_", "11", "00"].allSatisfy { bd.decodeBool(from: $0) == nil })
+    }
+
+    @available(Configuration 1.0, *)
+    @Test("boolDecoder, only .oneZero boolean strings enabled")
+    func boolDecoderOnlyOneZeroBooleanStringsEnabled() throws {
+        let bd = BoolDecoder(booleanStrings: [.oneZero])
+        #expect(bd.decodeBool(from: "1") == true)
+        #expect(bd.decodeBool(from: "0") == false)
+        #expect(bd.decodeBool(from: "true") == nil)
+        #expect(bd.decodeBool(from: "false") == nil)
+        #expect(bd.decodeBool(from: "yes") == nil)
+        #expect(bd.decodeBool(from: "no") == nil)
+    }
+}
diff --git a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
index ab72485..89da9fb 100644
--- a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
+++ b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
@@ -33,6 +33,10 @@ struct EnvironmentVariablesProviderTests {
                 "OTHER_DOUBLE": "2.72",
                 "BOOL": "true",
                 "OTHER_BOOL": "false",
+                "OTHER_BOOL_1": "1",
+                "OTHER_BOOL_0": "0",
+                "OTHER_BOOL_YES": "YES",
+                "OTHER_BOOL_NO": "NO",
                 "BYTES": "bWFnaWM=",
                 "OTHER_BYTES": "bWFnaWMy",
                 "STRINGY_ARRAY": "Hello,World",
@@ -43,6 +47,8 @@ struct EnvironmentVariablesProviderTests {
                 "OTHER_DOUBLY_ARRAY": "0.9,1.8",
                 "BOOLY_ARRAY": "true,false",
                 "OTHER_BOOLY_ARRAY": "false,true,true",
+                "OTHER_BOOLY_ARRAY_1_0": "0, 1, 1",
+                "OTHER_BOOLY_ARRAY_YES_NO": "NO, YES, YES",
                 "BYTE_CHUNKY_ARRAY": "bWFnaWM=,bWFnaWMy",
                 "OTHER_BYTE_CHUNKY_ARRAY": "bWFnaWM=,bWFnaWMy,bWFnaWM=",
             ],
@@ -55,7 +61,7 @@ struct EnvironmentVariablesProviderTests {
     @available(Configuration 1.0, *)
     @Test func printingDescription() throws {
         let expectedDescription = #"""
-            EnvironmentVariablesProvider[20 values]
+            EnvironmentVariablesProvider[26 values]
             """#
         #expect(provider.description == expectedDescription)
     }
@@ -63,11 +69,40 @@ struct EnvironmentVariablesProviderTests {
     @available(Configuration 1.0, *)
     @Test func printingDebugDescription() throws {
         let expectedDebugDescription = #"""
-            EnvironmentVariablesProvider[20 values: BOOL=true, BOOLY_ARRAY=true,false, BYTES=bWFnaWM=, BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy, DOUBLE=3.14, DOUBLY_ARRAY=3.14,2.72, INT=42, INTY_ARRAY=42,24, OTHER_BOOL=false, OTHER_BOOLY_ARRAY=false,true,true, OTHER_BYTES=bWFnaWMy, OTHER_BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy,bWFnaWM=, OTHER_DOUBLE=2.72, OTHER_DOUBLY_ARRAY=0.9,1.8, OTHER_INT=24, OTHER_INTY_ARRAY=16,32, OTHER_STRING=Other Hello, OTHER_STRINGY_ARRAY=Hello,Swift, STRING=<REDACTED>, STRINGY_ARRAY=Hello,World]
+            EnvironmentVariablesProvider[26 values: BOOL=true, BOOLY_ARRAY=true,false, BYTES=bWFnaWM=, BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy, DOUBLE=3.14, DOUBLY_ARRAY=3.14,2.72, INT=42, INTY_ARRAY=42,24, OTHER_BOOL=false, OTHER_BOOLY_ARRAY=false,true,true, OTHER_BOOLY_ARRAY_1_0=0, 1, 1, OTHER_BOOLY_ARRAY_YES_NO=NO, YES, YES, OTHER_BOOL_0=0, OTHER_BOOL_1=1, OTHER_BOOL_NO=NO, OTHER_BOOL_YES=YES, OTHER_BYTES=bWFnaWMy, OTHER_BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy,bWFnaWM=, OTHER_DOUBLE=2.72, OTHER_DOUBLY_ARRAY=0.9,1.8, OTHER_INT=24, OTHER_INTY_ARRAY=16,32, OTHER_STRING=Other Hello, OTHER_STRINGY_ARRAY=Hello,Swift, STRING=<REDACTED>, STRINGY_ARRAY=Hello,World]
             """#
         #expect(provider.debugDescription == expectedDebugDescription)
     }
 
+    @available(Configuration 1.0, *)
+    @Test func valuesForKeys() throws {
+        #expect(try provider.value(forKey: "OTHER_BOOL_1", type: .bool).value == true)
+        #expect(try provider.value(forKey: "OTHER_BOOL_0", type: .bool).value == false)
+        #expect(try provider.value(forKey: "OTHER_BOOL_YES", type: .bool).value == true)
+        #expect(try provider.value(forKey: "OTHER_BOOL_NO", type: .bool).value == false)
+        #expect(
+            try provider
+                .value(forKey: "OTHER_BOOLY_ARRAY", type: .boolArray).value == .init(
+                    [false, true, true],
+                    isSecret: false
+                )
+        )
+        #expect(
+            try provider
+                .value(forKey: "OTHER_BOOLY_ARRAY_1_0", type: .boolArray).value == .init(
+                    [false, true, true],
+                    isSecret: false
+                )
+        )
+        #expect(
+            try provider
+                .value(forKey: "OTHER_BOOLY_ARRAY_YES_NO", type: .boolArray).value == .init(
+                    [false, true, true],
+                    isSecret: false
+                )
+        )
+    }
+
     @available(Configuration 1.0, *)
     @Test func compat() async throws {
         try await ProviderCompatTest(provider: provider).runTest()

From 9b6bc7b9f253186d63afa456921852a5892c5735 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Tue, 16 Dec 2025 16:49:30 +0100
Subject: [PATCH 02/12] Update docc documentation

---
 .../Reference/EnvironmentVariablesProvider.md               | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md b/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md
index 8b20dbf..b0eead7 100644
--- a/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md
+++ b/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md
@@ -4,9 +4,9 @@
 
 ### Creating an environment variable provider
 
-- ``init(secretsSpecifier:bytesDecoder:arraySeparator:)``
-- ``init(environmentVariables:secretsSpecifier:bytesDecoder:arraySeparator:)``
-- ``init(environmentFilePath:allowMissing:secretsSpecifier:bytesDecoder:arraySeparator:)``
+- ``init(secretsSpecifier:bytesDecoder:boolDecoder:arraySeparator:)``
+- ``init(environmentVariables:secretsSpecifier:bytesDecoder:boolDecoder:arraySeparator:)``
+- ``init(environmentFilePath:allowMissing:secretsSpecifier:bytesDecoder:boolDecoder:arraySeparator:)``
 
 ### Inspecting an environment variable provider
 

From 85667b46e7789afc85fb83d0f7412c1c84846e97 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 10:53:18 +0100
Subject: [PATCH 03/12] Address review comments

- Remove boolDecoder init customization
- Revert changes to the default set of values in tests
- Create a dedicated test to cover various string boolean variants
---
 .../EnvironmentVariablesProvider.swift        |  8 +-
 .../ConfigBoolsFromStringDecoder.swift        | 43 +++-------
 .../ConfigBoolsFromStringDecoderTests.swift   | 38 ++++-----
 .../ConfigSnapshotReaderMethodTestsGet2.swift | 83 +++++--------------
 .../EnvironmentVariablesProviderTests.swift   | 64 +++++++-------
 5 files changed, 86 insertions(+), 150 deletions(-)

diff --git a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
index 013629c..c793270 100644
--- a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
+++ b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
@@ -173,7 +173,7 @@ public struct EnvironmentVariablesProvider: Sendable {
     public init(
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .allBooleanStrings,
+        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) {
         self.init(
@@ -212,7 +212,7 @@ public struct EnvironmentVariablesProvider: Sendable {
         environmentVariables: [String: String],
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .allBooleanStrings,
+        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) {
         let tuples: [(String, EnvironmentValue)] = environmentVariables.map { key, value in
@@ -262,7 +262,7 @@ public struct EnvironmentVariablesProvider: Sendable {
         allowMissing: Bool = false,
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .allBooleanStrings,
+        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) async throws {
         try await self.init(
@@ -294,7 +294,7 @@ public struct EnvironmentVariablesProvider: Sendable {
         fileSystem: some CommonProviderFileSystem,
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .allBooleanStrings,
+        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) async throws {
         let loadedData = try await fileSystem.fileContents(atPath: environmentFilePath)
diff --git a/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift b/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
index 6d92e6f..79fa852 100644
--- a/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
+++ b/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
@@ -21,44 +21,27 @@ import Foundation
 /// A decoder that converts a boolean string into a Bool, taking into account different boolean string pairs.
 ///
 /// This decoder is able to convert a string to Bool values when the string’s Boolean value format is 0 or 1, true or false, or yes or no.
-/// Boolean strings taken into account when decoding are configurable at init time only.
 ///
 /// ## Boolean values
 ///
-/// By default, following boolean string pairs are decoded to a Bool value: trueFalse (true, false), oneZero (1, 0), yesNo (yes, no).
+/// Following boolean string pairs are decoded to a Bool value: trueFalse (true, false), oneZero (1, 0), yesNo (yes, no).
 /// Decoding is case-insensitive.
 @available(Configuration 1.0, *)
 public struct BoolDecoder: Sendable {
 
-    public enum BooleanString: Sendable { case trueFalse, oneZero, yesNo }
+    /// Creates a new bool decoder.
+    public init() {}
 
-    public static var allBooleanStrings: Self { .init(booleanStrings: [.trueFalse, .oneZero, .yesNo]) }
-
-    private let booleanStrings: [BooleanString]
-
-    public init(booleanStrings: [BooleanString]) {
-        self.booleanStrings = booleanStrings
-    }
-
-    func decodeBool(from string: String) -> Bool? {
-        for semantic in self.booleanStrings {
-            switch semantic {
-            case .trueFalse:
-                let stringLowercased = string.lowercased()
-                if ["true", "false"].contains(stringLowercased) {
-                    return stringLowercased == "true"
-                }
-            case .oneZero:
-                if ["1", "0"].contains(string) {
-                    return string == "1"
-                }
-            case .yesNo:
-                let stringLowercased = string.lowercased()
-                if ["yes", "no"].contains(stringLowercased) {
-                    return stringLowercased == "yes"
-                }
-            }
+    public func decodeBool(from string: String) -> Bool? {
+        let stringLowercased = string.lowercased()
+        return if ["true", "false"].contains(stringLowercased) {
+            stringLowercased == "true"
+        } else if ["yes", "no"].contains(stringLowercased) {
+            stringLowercased == "yes"
+        } else if ["1", "0"].contains(stringLowercased) {
+            stringLowercased == "1"
+        } else {
+            nil
         }
-        return nil
     }
 }
diff --git a/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift b/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
index 70bcb92..a3445fa 100644
--- a/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
+++ b/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
@@ -18,28 +18,24 @@ import Foundation
 
 struct ConfigBoolsFromStringDecoderTests {
 
+    @Test()
     @available(Configuration 1.0, *)
-    @Test("boolDecoder, all boolean strings enabled")
-    func boolDecoderAllBooleanStringsEnabled() throws {
-        let bd = BoolDecoder(booleanStrings: [.oneZero, .trueFalse, .yesNo])
-        #expect(bd.decodeBool(from: "1") == true)
-        #expect(bd.decodeBool(from: "0") == false)
-        #expect(["Yes", "yes", "YES", "yES"].allSatisfy { bd.decodeBool(from: $0) == true })
-        #expect(["No", "no", "NO", "nO"].allSatisfy { bd.decodeBool(from: $0) == false })
-        #expect(["true", "TRUE", "trUe"].allSatisfy { bd.decodeBool(from: $0) == true })
-        #expect(["false", "FALSE", "faLse"].allSatisfy { bd.decodeBool(from: $0) == false })
-        #expect(["_true_", "_false_", "11", "00"].allSatisfy { bd.decodeBool(from: $0) == nil })
-    }
+    func stringToBool() throws {
+        let bd = BoolDecoder()
+        let cases: [(expected: Bool?, input: [String])] = [
+            (true, ["1"]),
+            (false, ["0"]),
+            (true, ["Yes", "yes", "YES", "yES"]),
+            (false, ["No", "no", "NO", "nO"]),
+            (true, ["true", "TRUE", "trUe"]),
+            (false, ["false", "FALSE", "faLse"]),
+            (nil, ["", "_true_", "_false_", "_yes_", "_no_", "_1_", "_0_", "11", "00"])
+        ]
 
-    @available(Configuration 1.0, *)
-    @Test("boolDecoder, only .oneZero boolean strings enabled")
-    func boolDecoderOnlyOneZeroBooleanStringsEnabled() throws {
-        let bd = BoolDecoder(booleanStrings: [.oneZero])
-        #expect(bd.decodeBool(from: "1") == true)
-        #expect(bd.decodeBool(from: "0") == false)
-        #expect(bd.decodeBool(from: "true") == nil)
-        #expect(bd.decodeBool(from: "false") == nil)
-        #expect(bd.decodeBool(from: "yes") == nil)
-        #expect(bd.decodeBool(from: "no") == nil)
+        for (expected, inputs) in cases {
+            for input in inputs {
+                #expect(bd.decodeBool(from: input) == expected, "input: \(input)")
+            }
+        }
     }
 }
diff --git a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
index 1ae2735..991475b 100644
--- a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
+++ b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
@@ -12,18 +12,20 @@
 //
 //===----------------------------------------------------------------------===//
 
-// #############################################################################
-// #                                                                           #
-// #            DO NOT EDIT THIS FILE; IT IS AUTOGENERATED.                    #
-// #                                                                           #
-// #############################################################################
+
+    // #############################################################################
+    // #                                                                           #
+    // #            DO NOT EDIT THIS FILE; IT IS AUTOGENERATED.                    #
+    // #                                                                           #
+    // #############################################################################
+    
 
 import Testing
 @testable import Configuration
 import ConfigurationTestingInternal
 
 struct ConfigSnapshotReaderMethodTestsGet2 {
-
+    
     typealias Defaults = ConfigReaderTests.Defaults
     typealias TestEnum = ConfigReaderTests.TestEnum
     typealias TestStringConvertible = ConfigReaderTests.TestStringConvertible
@@ -32,14 +34,11 @@ struct ConfigSnapshotReaderMethodTestsGet2 {
     @Test func get() async throws {
         let config = ConfigReaderTests.config
 
-        do {
+        do { 
             let snapshot = config.snapshot()
 
             // Optional - success
-            #expect(
-                snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self)
-                    == Defaults.stringConvertible
-            )
+            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
 
             // Optional - missing
             #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self) == nil)
@@ -48,50 +47,25 @@ struct ConfigSnapshotReaderMethodTestsGet2 {
             #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self) == nil)
 
             // Defaulted - success
-            #expect(
-                snapshot.string(
-                    forKey: "stringConvertible",
-                    as: TestStringConvertible.self,
-                    default: Defaults.otherStringConvertible
-                ) == Defaults.stringConvertible
-            )
+            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.stringConvertible)
 
             // Defaulted - missing
-            #expect(
-                snapshot.string(
-                    forKey: "absentStringConvertible",
-                    as: TestStringConvertible.self,
-                    default: Defaults.otherStringConvertible
-                ) == Defaults.otherStringConvertible
-            )
+            #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
 
             // Defaulted - failing
-            #expect(
-                snapshot.string(
-                    forKey: "failure",
-                    as: TestStringConvertible.self,
-                    default: Defaults.otherStringConvertible
-                ) == Defaults.otherStringConvertible
-            )
+            #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
 
             // Required - success
-            try #expect(
-                snapshot.requiredString(forKey: "stringConvertible", as: TestStringConvertible.self)
-                    == Defaults.stringConvertible
-            )
+            try #expect(snapshot.requiredString(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
 
             // Required - missing
-            let error1 = #expect(throws: ConfigError.self) {
-                try snapshot.requiredString(forKey: "absentStringConvertible", as: TestStringConvertible.self)
-            }
+            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringConvertible", as: TestStringConvertible.self) }
             #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringConvertible"])))
 
             // Required - failing
-            #expect(throws: TestProvider.TestError.self) {
-                try snapshot.requiredString(forKey: "failure", as: TestStringConvertible.self)
-            }
+            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestStringConvertible.self) }
         }
-        do {
+        do { 
             let snapshot = config.snapshot()
 
             // Optional - success
@@ -104,36 +78,23 @@ struct ConfigSnapshotReaderMethodTestsGet2 {
             #expect(snapshot.string(forKey: "failure", as: TestEnum.self) == nil)
 
             // Defaulted - success
-            #expect(
-                snapshot.string(forKey: "stringEnum", as: TestEnum.self, default: Defaults.otherStringEnum)
-                    == Defaults.stringEnum
-            )
+            #expect(snapshot.string(forKey: "stringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.stringEnum)
 
             // Defaulted - missing
-            #expect(
-                snapshot.string(forKey: "absentStringEnum", as: TestEnum.self, default: Defaults.otherStringEnum)
-                    == Defaults.otherStringEnum
-            )
+            #expect(snapshot.string(forKey: "absentStringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
 
             // Defaulted - failing
-            #expect(
-                snapshot.string(forKey: "failure", as: TestEnum.self, default: Defaults.otherStringEnum)
-                    == Defaults.otherStringEnum
-            )
+            #expect(snapshot.string(forKey: "failure", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
 
             // Required - success
             try #expect(snapshot.requiredString(forKey: "stringEnum", as: TestEnum.self) == Defaults.stringEnum)
 
             // Required - missing
-            let error1 = #expect(throws: ConfigError.self) {
-                try snapshot.requiredString(forKey: "absentStringEnum", as: TestEnum.self)
-            }
+            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringEnum", as: TestEnum.self) }
             #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringEnum"])))
 
             // Required - failing
-            #expect(throws: TestProvider.TestError.self) {
-                try snapshot.requiredString(forKey: "failure", as: TestEnum.self)
-            }
+            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestEnum.self) }
         }
     }
 }
diff --git a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
index 89da9fb..ab06b22 100644
--- a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
+++ b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
@@ -33,10 +33,6 @@ struct EnvironmentVariablesProviderTests {
                 "OTHER_DOUBLE": "2.72",
                 "BOOL": "true",
                 "OTHER_BOOL": "false",
-                "OTHER_BOOL_1": "1",
-                "OTHER_BOOL_0": "0",
-                "OTHER_BOOL_YES": "YES",
-                "OTHER_BOOL_NO": "NO",
                 "BYTES": "bWFnaWM=",
                 "OTHER_BYTES": "bWFnaWMy",
                 "STRINGY_ARRAY": "Hello,World",
@@ -47,8 +43,6 @@ struct EnvironmentVariablesProviderTests {
                 "OTHER_DOUBLY_ARRAY": "0.9,1.8",
                 "BOOLY_ARRAY": "true,false",
                 "OTHER_BOOLY_ARRAY": "false,true,true",
-                "OTHER_BOOLY_ARRAY_1_0": "0, 1, 1",
-                "OTHER_BOOLY_ARRAY_YES_NO": "NO, YES, YES",
                 "BYTE_CHUNKY_ARRAY": "bWFnaWM=,bWFnaWMy",
                 "OTHER_BYTE_CHUNKY_ARRAY": "bWFnaWM=,bWFnaWMy,bWFnaWM=",
             ],
@@ -61,7 +55,7 @@ struct EnvironmentVariablesProviderTests {
     @available(Configuration 1.0, *)
     @Test func printingDescription() throws {
         let expectedDescription = #"""
-            EnvironmentVariablesProvider[26 values]
+            EnvironmentVariablesProvider[20 values]
             """#
         #expect(provider.description == expectedDescription)
     }
@@ -69,38 +63,40 @@ struct EnvironmentVariablesProviderTests {
     @available(Configuration 1.0, *)
     @Test func printingDebugDescription() throws {
         let expectedDebugDescription = #"""
-            EnvironmentVariablesProvider[26 values: BOOL=true, BOOLY_ARRAY=true,false, BYTES=bWFnaWM=, BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy, DOUBLE=3.14, DOUBLY_ARRAY=3.14,2.72, INT=42, INTY_ARRAY=42,24, OTHER_BOOL=false, OTHER_BOOLY_ARRAY=false,true,true, OTHER_BOOLY_ARRAY_1_0=0, 1, 1, OTHER_BOOLY_ARRAY_YES_NO=NO, YES, YES, OTHER_BOOL_0=0, OTHER_BOOL_1=1, OTHER_BOOL_NO=NO, OTHER_BOOL_YES=YES, OTHER_BYTES=bWFnaWMy, OTHER_BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy,bWFnaWM=, OTHER_DOUBLE=2.72, OTHER_DOUBLY_ARRAY=0.9,1.8, OTHER_INT=24, OTHER_INTY_ARRAY=16,32, OTHER_STRING=Other Hello, OTHER_STRINGY_ARRAY=Hello,Swift, STRING=<REDACTED>, STRINGY_ARRAY=Hello,World]
+            EnvironmentVariablesProvider[20 values: BOOL=true, BOOLY_ARRAY=true,false, BYTES=bWFnaWM=, BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy, DOUBLE=3.14, DOUBLY_ARRAY=3.14,2.72, INT=42, INTY_ARRAY=42,24, OTHER_BOOL=false, OTHER_BOOLY_ARRAY=false,true,true, OTHER_BYTES=bWFnaWMy, OTHER_BYTE_CHUNKY_ARRAY=bWFnaWM=,bWFnaWMy,bWFnaWM=, OTHER_DOUBLE=2.72, OTHER_DOUBLY_ARRAY=0.9,1.8, OTHER_INT=24, OTHER_INTY_ARRAY=16,32, OTHER_STRING=Other Hello, OTHER_STRINGY_ARRAY=Hello,Swift, STRING=<REDACTED>, STRINGY_ARRAY=Hello,World]
             """#
         #expect(provider.debugDescription == expectedDebugDescription)
     }
 
     @available(Configuration 1.0, *)
-    @Test func valuesForKeys() throws {
-        #expect(try provider.value(forKey: "OTHER_BOOL_1", type: .bool).value == true)
-        #expect(try provider.value(forKey: "OTHER_BOOL_0", type: .bool).value == false)
-        #expect(try provider.value(forKey: "OTHER_BOOL_YES", type: .bool).value == true)
-        #expect(try provider.value(forKey: "OTHER_BOOL_NO", type: .bool).value == false)
-        #expect(
-            try provider
-                .value(forKey: "OTHER_BOOLY_ARRAY", type: .boolArray).value == .init(
-                    [false, true, true],
-                    isSecret: false
-                )
-        )
-        #expect(
-            try provider
-                .value(forKey: "OTHER_BOOLY_ARRAY_1_0", type: .boolArray).value == .init(
-                    [false, true, true],
-                    isSecret: false
-                )
-        )
-        #expect(
-            try provider
-                .value(forKey: "OTHER_BOOLY_ARRAY_YES_NO", type: .boolArray).value == .init(
-                    [false, true, true],
-                    isSecret: false
-                )
-        )
+    @Test func boolDecoderValuesForKeys() throws {
+        let ep = EnvironmentVariablesProvider(
+            environmentVariables: [
+                "BOOL_TRUE": "true",
+                "BOOL_FALSE": "false",
+                "BOOL_1": "1",
+                "BOOL_0": "0",
+                "BOOL_YES": "YES",
+                "BOOL_NO": "NO",
+                "BOOL_THROWS_ERROR_EMPTY": "",
+                "BOOL_THROWS_ERROR_NOT_BOOL_STRING": "2",
+                "BOOLY_ARRAY_TRUE": "true,1,,YES",
+                "BOOLY_ARRAY_FALSE": "false,0,NO",
+                "BOOLY_ARRAY_THROWS_1": "true,1,YESS",
+                "BOOLY_ARRAY_THROWS_2": "false,00,no",
+            ])
+        #expect(try ep.value(forKey: "BOOL_TRUE", type: .bool).value == true)
+        #expect(try ep.value(forKey: "BOOL_FALSE", type: .bool).value == false)
+        #expect(try ep.value(forKey: "BOOL_1", type: .bool).value == true)
+        #expect(try ep.value(forKey: "BOOL_0", type: .bool).value == false)
+        #expect(try ep.value(forKey: "BOOL_YES", type: .bool).value == true)
+        #expect(try ep.value(forKey: "BOOL_NO", type: .bool).value == false)
+        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOL_THROWS_ERROR_EMPTY", type: .bool) }
+        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOL_THROWS_ERROR_NOT_BOOL_STRING", type: .bool) }
+        #expect(try ep.value(forKey: "BOOLY_ARRAY_TRUE", type: .boolArray).value == .init([true, true, true], isSecret: false))
+        #expect(try ep.value(forKey: "BOOLY_ARRAY_FALSE", type: .boolArray).value == .init([false, false, false], isSecret: false))
+        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOLY_ARRAY_THROWS_1", type: .boolArray) }
+        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOLY_ARRAY_THROWS_2", type: .boolArray) }
     }
 
     @available(Configuration 1.0, *)

From 5ba67cb414d9f00461b5ff17a291d45e16cf95d2 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 11:03:56 +0100
Subject: [PATCH 04/12] Delete a generated file

---
 .../ConfigSnapshotReaderMethodTestsGet2.swift | 100 ------------------
 1 file changed, 100 deletions(-)
 delete mode 100644 Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift

diff --git a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
deleted file mode 100644
index 991475b..0000000
--- a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
+++ /dev/null
@@ -1,100 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// This source file is part of the SwiftConfiguration open source project
-//
-// Copyright (c) 2025 Apple Inc. and the SwiftConfiguration project authors
-// Licensed under Apache License v2.0
-//
-// See LICENSE.txt for license information
-// See CONTRIBUTORS.txt for the list of SwiftConfiguration project authors
-//
-// SPDX-License-Identifier: Apache-2.0
-//
-//===----------------------------------------------------------------------===//
-
-
-    // #############################################################################
-    // #                                                                           #
-    // #            DO NOT EDIT THIS FILE; IT IS AUTOGENERATED.                    #
-    // #                                                                           #
-    // #############################################################################
-    
-
-import Testing
-@testable import Configuration
-import ConfigurationTestingInternal
-
-struct ConfigSnapshotReaderMethodTestsGet2 {
-    
-    typealias Defaults = ConfigReaderTests.Defaults
-    typealias TestEnum = ConfigReaderTests.TestEnum
-    typealias TestStringConvertible = ConfigReaderTests.TestStringConvertible
-
-    @available(Configuration 1.0, *)
-    @Test func get() async throws {
-        let config = ConfigReaderTests.config
-
-        do { 
-            let snapshot = config.snapshot()
-
-            // Optional - success
-            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
-
-            // Optional - missing
-            #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self) == nil)
-
-            // Optional - failing
-            #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self) == nil)
-
-            // Defaulted - success
-            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.stringConvertible)
-
-            // Defaulted - missing
-            #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
-
-            // Defaulted - failing
-            #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
-
-            // Required - success
-            try #expect(snapshot.requiredString(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
-
-            // Required - missing
-            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringConvertible", as: TestStringConvertible.self) }
-            #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringConvertible"])))
-
-            // Required - failing
-            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestStringConvertible.self) }
-        }
-        do { 
-            let snapshot = config.snapshot()
-
-            // Optional - success
-            #expect(snapshot.string(forKey: "stringEnum", as: TestEnum.self) == Defaults.stringEnum)
-
-            // Optional - missing
-            #expect(snapshot.string(forKey: "absentStringEnum", as: TestEnum.self) == nil)
-
-            // Optional - failing
-            #expect(snapshot.string(forKey: "failure", as: TestEnum.self) == nil)
-
-            // Defaulted - success
-            #expect(snapshot.string(forKey: "stringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.stringEnum)
-
-            // Defaulted - missing
-            #expect(snapshot.string(forKey: "absentStringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
-
-            // Defaulted - failing
-            #expect(snapshot.string(forKey: "failure", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
-
-            // Required - success
-            try #expect(snapshot.requiredString(forKey: "stringEnum", as: TestEnum.self) == Defaults.stringEnum)
-
-            // Required - missing
-            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringEnum", as: TestEnum.self) }
-            #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringEnum"])))
-
-            // Required - failing
-            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestEnum.self) }
-        }
-    }
-}

From e235d9bef01baab6ee286fdcf3e5f18d01ca3e0d Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 11:05:56 +0100
Subject: [PATCH 05/12] Rename test name

boolDecoderValuesForKeys -> valueForKeyOfBoolAndBoolArrayTypes
---
 .../ConfigurationTests/EnvironmentVariablesProviderTests.swift  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
index ab06b22..2131cc8 100644
--- a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
+++ b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
@@ -69,7 +69,7 @@ struct EnvironmentVariablesProviderTests {
     }
 
     @available(Configuration 1.0, *)
-    @Test func boolDecoderValuesForKeys() throws {
+    @Test func valueForKeyOfBoolAndBoolArrayTypes() throws {
         let ep = EnvironmentVariablesProvider(
             environmentVariables: [
                 "BOOL_TRUE": "true",

From eaf878d2a04e9c8e24ce8bba09e909bf09411483 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 11:09:54 +0100
Subject: [PATCH 06/12] Revert "Delete a generated file"

This reverts commit 5ba67cb414d9f00461b5ff17a291d45e16cf95d2.
---
 .../ConfigSnapshotReaderMethodTestsGet2.swift | 100 ++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift

diff --git a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
new file mode 100644
index 0000000..991475b
--- /dev/null
+++ b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
@@ -0,0 +1,100 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftConfiguration open source project
+//
+// Copyright (c) 2025 Apple Inc. and the SwiftConfiguration project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftConfiguration project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+
+    // #############################################################################
+    // #                                                                           #
+    // #            DO NOT EDIT THIS FILE; IT IS AUTOGENERATED.                    #
+    // #                                                                           #
+    // #############################################################################
+    
+
+import Testing
+@testable import Configuration
+import ConfigurationTestingInternal
+
+struct ConfigSnapshotReaderMethodTestsGet2 {
+    
+    typealias Defaults = ConfigReaderTests.Defaults
+    typealias TestEnum = ConfigReaderTests.TestEnum
+    typealias TestStringConvertible = ConfigReaderTests.TestStringConvertible
+
+    @available(Configuration 1.0, *)
+    @Test func get() async throws {
+        let config = ConfigReaderTests.config
+
+        do { 
+            let snapshot = config.snapshot()
+
+            // Optional - success
+            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
+
+            // Optional - missing
+            #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self) == nil)
+
+            // Optional - failing
+            #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self) == nil)
+
+            // Defaulted - success
+            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.stringConvertible)
+
+            // Defaulted - missing
+            #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
+
+            // Defaulted - failing
+            #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
+
+            // Required - success
+            try #expect(snapshot.requiredString(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
+
+            // Required - missing
+            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringConvertible", as: TestStringConvertible.self) }
+            #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringConvertible"])))
+
+            // Required - failing
+            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestStringConvertible.self) }
+        }
+        do { 
+            let snapshot = config.snapshot()
+
+            // Optional - success
+            #expect(snapshot.string(forKey: "stringEnum", as: TestEnum.self) == Defaults.stringEnum)
+
+            // Optional - missing
+            #expect(snapshot.string(forKey: "absentStringEnum", as: TestEnum.self) == nil)
+
+            // Optional - failing
+            #expect(snapshot.string(forKey: "failure", as: TestEnum.self) == nil)
+
+            // Defaulted - success
+            #expect(snapshot.string(forKey: "stringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.stringEnum)
+
+            // Defaulted - missing
+            #expect(snapshot.string(forKey: "absentStringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
+
+            // Defaulted - failing
+            #expect(snapshot.string(forKey: "failure", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
+
+            // Required - success
+            try #expect(snapshot.requiredString(forKey: "stringEnum", as: TestEnum.self) == Defaults.stringEnum)
+
+            // Required - missing
+            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringEnum", as: TestEnum.self) }
+            #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringEnum"])))
+
+            // Required - failing
+            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestEnum.self) }
+        }
+    }
+}

From 0f3bde29537c8c0376c636745d72c514b6a4f5cb Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 11:13:22 +0100
Subject: [PATCH 07/12] Revert accidental file changes.

---
 .../ConfigSnapshotReaderMethodTestsGet2.swift | 83 ++++++++++++++-----
 1 file changed, 61 insertions(+), 22 deletions(-)

diff --git a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
index 991475b..1ae2735 100644
--- a/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
+++ b/Tests/ConfigurationTests/ConfigReaderTests/ConfigSnapshotReaderMethodTestsGet2.swift
@@ -12,20 +12,18 @@
 //
 //===----------------------------------------------------------------------===//
 
-
-    // #############################################################################
-    // #                                                                           #
-    // #            DO NOT EDIT THIS FILE; IT IS AUTOGENERATED.                    #
-    // #                                                                           #
-    // #############################################################################
-    
+// #############################################################################
+// #                                                                           #
+// #            DO NOT EDIT THIS FILE; IT IS AUTOGENERATED.                    #
+// #                                                                           #
+// #############################################################################
 
 import Testing
 @testable import Configuration
 import ConfigurationTestingInternal
 
 struct ConfigSnapshotReaderMethodTestsGet2 {
-    
+
     typealias Defaults = ConfigReaderTests.Defaults
     typealias TestEnum = ConfigReaderTests.TestEnum
     typealias TestStringConvertible = ConfigReaderTests.TestStringConvertible
@@ -34,11 +32,14 @@ struct ConfigSnapshotReaderMethodTestsGet2 {
     @Test func get() async throws {
         let config = ConfigReaderTests.config
 
-        do { 
+        do {
             let snapshot = config.snapshot()
 
             // Optional - success
-            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
+            #expect(
+                snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self)
+                    == Defaults.stringConvertible
+            )
 
             // Optional - missing
             #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self) == nil)
@@ -47,25 +48,50 @@ struct ConfigSnapshotReaderMethodTestsGet2 {
             #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self) == nil)
 
             // Defaulted - success
-            #expect(snapshot.string(forKey: "stringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.stringConvertible)
+            #expect(
+                snapshot.string(
+                    forKey: "stringConvertible",
+                    as: TestStringConvertible.self,
+                    default: Defaults.otherStringConvertible
+                ) == Defaults.stringConvertible
+            )
 
             // Defaulted - missing
-            #expect(snapshot.string(forKey: "absentStringConvertible", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
+            #expect(
+                snapshot.string(
+                    forKey: "absentStringConvertible",
+                    as: TestStringConvertible.self,
+                    default: Defaults.otherStringConvertible
+                ) == Defaults.otherStringConvertible
+            )
 
             // Defaulted - failing
-            #expect(snapshot.string(forKey: "failure", as: TestStringConvertible.self, default: Defaults.otherStringConvertible) == Defaults.otherStringConvertible)
+            #expect(
+                snapshot.string(
+                    forKey: "failure",
+                    as: TestStringConvertible.self,
+                    default: Defaults.otherStringConvertible
+                ) == Defaults.otherStringConvertible
+            )
 
             // Required - success
-            try #expect(snapshot.requiredString(forKey: "stringConvertible", as: TestStringConvertible.self) == Defaults.stringConvertible)
+            try #expect(
+                snapshot.requiredString(forKey: "stringConvertible", as: TestStringConvertible.self)
+                    == Defaults.stringConvertible
+            )
 
             // Required - missing
-            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringConvertible", as: TestStringConvertible.self) }
+            let error1 = #expect(throws: ConfigError.self) {
+                try snapshot.requiredString(forKey: "absentStringConvertible", as: TestStringConvertible.self)
+            }
             #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringConvertible"])))
 
             // Required - failing
-            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestStringConvertible.self) }
+            #expect(throws: TestProvider.TestError.self) {
+                try snapshot.requiredString(forKey: "failure", as: TestStringConvertible.self)
+            }
         }
-        do { 
+        do {
             let snapshot = config.snapshot()
 
             // Optional - success
@@ -78,23 +104,36 @@ struct ConfigSnapshotReaderMethodTestsGet2 {
             #expect(snapshot.string(forKey: "failure", as: TestEnum.self) == nil)
 
             // Defaulted - success
-            #expect(snapshot.string(forKey: "stringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.stringEnum)
+            #expect(
+                snapshot.string(forKey: "stringEnum", as: TestEnum.self, default: Defaults.otherStringEnum)
+                    == Defaults.stringEnum
+            )
 
             // Defaulted - missing
-            #expect(snapshot.string(forKey: "absentStringEnum", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
+            #expect(
+                snapshot.string(forKey: "absentStringEnum", as: TestEnum.self, default: Defaults.otherStringEnum)
+                    == Defaults.otherStringEnum
+            )
 
             // Defaulted - failing
-            #expect(snapshot.string(forKey: "failure", as: TestEnum.self, default: Defaults.otherStringEnum) == Defaults.otherStringEnum)
+            #expect(
+                snapshot.string(forKey: "failure", as: TestEnum.self, default: Defaults.otherStringEnum)
+                    == Defaults.otherStringEnum
+            )
 
             // Required - success
             try #expect(snapshot.requiredString(forKey: "stringEnum", as: TestEnum.self) == Defaults.stringEnum)
 
             // Required - missing
-            let error1 = #expect(throws: ConfigError.self) { try snapshot.requiredString(forKey: "absentStringEnum", as: TestEnum.self) }
+            let error1 = #expect(throws: ConfigError.self) {
+                try snapshot.requiredString(forKey: "absentStringEnum", as: TestEnum.self)
+            }
             #expect(error1 == .missingRequiredConfigValue(AbsoluteConfigKey(["absentStringEnum"])))
 
             // Required - failing
-            #expect(throws: TestProvider.TestError.self) { try snapshot.requiredString(forKey: "failure", as: TestEnum.self) }
+            #expect(throws: TestProvider.TestError.self) {
+                try snapshot.requiredString(forKey: "failure", as: TestEnum.self)
+            }
         }
     }
 }

From d45e629784a4e163782303a32fdd0e4f1242b1fe Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 14:02:32 +0100
Subject: [PATCH 08/12] Move decodeBool to Snapshot of
 EnvironmentVariablesProvider

Apply review comments
---
 .../Reference/EnvironmentVariablesProvider.md |  6 +--
 .../EnvironmentVariablesProvider.swift        | 27 ++++++-----
 .../ConfigBoolsFromStringDecoder.swift        | 47 -------------------
 .../ConfigBoolsFromStringDecoderTests.swift   | 41 ----------------
 .../EnvironmentVariablesProviderTests.swift   | 20 ++++++++
 5 files changed, 38 insertions(+), 103 deletions(-)
 delete mode 100644 Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
 delete mode 100644 Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift

diff --git a/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md b/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md
index b0eead7..8b20dbf 100644
--- a/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md
+++ b/Sources/Configuration/Documentation.docc/Reference/EnvironmentVariablesProvider.md
@@ -4,9 +4,9 @@
 
 ### Creating an environment variable provider
 
-- ``init(secretsSpecifier:bytesDecoder:boolDecoder:arraySeparator:)``
-- ``init(environmentVariables:secretsSpecifier:bytesDecoder:boolDecoder:arraySeparator:)``
-- ``init(environmentFilePath:allowMissing:secretsSpecifier:bytesDecoder:boolDecoder:arraySeparator:)``
+- ``init(secretsSpecifier:bytesDecoder:arraySeparator:)``
+- ``init(environmentVariables:secretsSpecifier:bytesDecoder:arraySeparator:)``
+- ``init(environmentFilePath:allowMissing:secretsSpecifier:bytesDecoder:arraySeparator:)``
 
 ### Inspecting an environment variable provider
 
diff --git a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
index c793270..08e2a72 100644
--- a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
+++ b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
@@ -144,7 +144,18 @@ public struct EnvironmentVariablesProvider: Sendable {
         var arrayDecoder: EnvironmentValueArrayDecoder
 
         /// A decoder of bool values from a string
-        let boolDecoder: BoolDecoder
+        static func decodeBool(from string: String) -> Bool? {
+            let stringLowercased = string.lowercased()
+            return if ["true", "false"].contains(stringLowercased) {
+                stringLowercased == "true"
+            } else if ["yes", "no"].contains(stringLowercased) {
+                stringLowercased == "yes"
+            } else if ["1", "0"].contains(stringLowercased) {
+                stringLowercased == "1"
+            } else {
+                nil
+            }
+        }
     }
 
     /// The underlying snapshot of the provider.
@@ -173,14 +184,12 @@ public struct EnvironmentVariablesProvider: Sendable {
     public init(
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) {
         self.init(
             environmentVariables: ProcessInfo.processInfo.environment,
             secretsSpecifier: secretsSpecifier,
             bytesDecoder: bytesDecoder,
-            boolDecoder: boolDecoder,
             arraySeparator: arraySeparator
         )
     }
@@ -212,7 +221,6 @@ public struct EnvironmentVariablesProvider: Sendable {
         environmentVariables: [String: String],
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) {
         let tuples: [(String, EnvironmentValue)] = environmentVariables.map { key, value in
@@ -227,8 +235,7 @@ public struct EnvironmentVariablesProvider: Sendable {
         self._snapshot = .init(
             environmentVariables: Dictionary(uniqueKeysWithValues: tuples),
             bytesDecoder: bytesDecoder,
-            arrayDecoder: EnvironmentValueArrayDecoder(separator: arraySeparator),
-            boolDecoder: boolDecoder
+            arrayDecoder: EnvironmentValueArrayDecoder(separator: arraySeparator)
         )
     }
 
@@ -262,7 +269,6 @@ public struct EnvironmentVariablesProvider: Sendable {
         allowMissing: Bool = false,
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) async throws {
         try await self.init(
@@ -271,7 +277,6 @@ public struct EnvironmentVariablesProvider: Sendable {
             fileSystem: LocalCommonProviderFileSystem(),
             secretsSpecifier: secretsSpecifier,
             bytesDecoder: bytesDecoder,
-            boolDecoder: boolDecoder,
             arraySeparator: arraySeparator
         )
     }
@@ -294,7 +299,6 @@ public struct EnvironmentVariablesProvider: Sendable {
         fileSystem: some CommonProviderFileSystem,
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
         bytesDecoder: some ConfigBytesFromStringDecoder = .base64,
-        boolDecoder: BoolDecoder = .init(),
         arraySeparator: Character = ","
     ) async throws {
         let loadedData = try await fileSystem.fileContents(atPath: environmentFilePath)
@@ -311,7 +315,6 @@ public struct EnvironmentVariablesProvider: Sendable {
             environmentVariables: EnvironmentFileParser.parsed(contents),
             secretsSpecifier: secretsSpecifier,
             bytesDecoder: bytesDecoder,
-            boolDecoder: boolDecoder,
             arraySeparator: arraySeparator
         )
     }
@@ -408,7 +411,7 @@ extension EnvironmentVariablesProvider.Snapshot {
             }
             content = .double(doubleValue)
         case .bool:
-            guard let boolValue = boolDecoder.decodeBool(from: stringValue) else {
+            guard let boolValue = Self.decodeBool(from: stringValue) else {
                 try throwMismatch()
             }
             content = .bool(boolValue)
@@ -441,7 +444,7 @@ extension EnvironmentVariablesProvider.Snapshot {
         case .boolArray:
             let arrayValue = arrayDecoder.decode(stringValue)
             let boolArray = try arrayValue.map { stringValue in
-                guard let boolValue = boolDecoder.decodeBool(from: stringValue) else {
+                guard let boolValue = Self.decodeBool(from: stringValue) else {
                     try throwMismatch()
                 }
                 return boolValue
diff --git a/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift b/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
deleted file mode 100644
index 79fa852..0000000
--- a/Sources/Configuration/ValueCoders/ConfigBoolsFromStringDecoder.swift
+++ /dev/null
@@ -1,47 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// This source file is part of the SwiftConfiguration open source project
-//
-// Copyright (c) 2025 Apple Inc. and the SwiftConfiguration project authors
-// Licensed under Apache License v2.0
-//
-// See LICENSE.txt for license information
-// See CONTRIBUTORS.txt for the list of SwiftConfiguration project authors
-//
-// SPDX-License-Identifier: Apache-2.0
-//
-//===----------------------------------------------------------------------===//
-
-#if canImport(FoundationEssentials)
-import FoundationEssentials
-#else
-import Foundation
-#endif
-
-/// A decoder that converts a boolean string into a Bool, taking into account different boolean string pairs.
-///
-/// This decoder is able to convert a string to Bool values when the string’s Boolean value format is 0 or 1, true or false, or yes or no.
-///
-/// ## Boolean values
-///
-/// Following boolean string pairs are decoded to a Bool value: trueFalse (true, false), oneZero (1, 0), yesNo (yes, no).
-/// Decoding is case-insensitive.
-@available(Configuration 1.0, *)
-public struct BoolDecoder: Sendable {
-
-    /// Creates a new bool decoder.
-    public init() {}
-
-    public func decodeBool(from string: String) -> Bool? {
-        let stringLowercased = string.lowercased()
-        return if ["true", "false"].contains(stringLowercased) {
-            stringLowercased == "true"
-        } else if ["yes", "no"].contains(stringLowercased) {
-            stringLowercased == "yes"
-        } else if ["1", "0"].contains(stringLowercased) {
-            stringLowercased == "1"
-        } else {
-            nil
-        }
-    }
-}
diff --git a/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift b/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
deleted file mode 100644
index a3445fa..0000000
--- a/Tests/ConfigurationTests/ConfigBoolsFromStringDecoderTests.swift
+++ /dev/null
@@ -1,41 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// This source file is part of the SwiftConfiguration open source project
-//
-// Copyright (c) 2025 Apple Inc. and the SwiftConfiguration project authors
-// Licensed under Apache License v2.0
-//
-// See LICENSE.txt for license information
-// See CONTRIBUTORS.txt for the list of SwiftConfiguration project authors
-//
-// SPDX-License-Identifier: Apache-2.0
-//
-//===----------------------------------------------------------------------===//
-
-import Testing
-import Foundation
-@testable import Configuration
-
-struct ConfigBoolsFromStringDecoderTests {
-
-    @Test()
-    @available(Configuration 1.0, *)
-    func stringToBool() throws {
-        let bd = BoolDecoder()
-        let cases: [(expected: Bool?, input: [String])] = [
-            (true, ["1"]),
-            (false, ["0"]),
-            (true, ["Yes", "yes", "YES", "yES"]),
-            (false, ["No", "no", "NO", "nO"]),
-            (true, ["true", "TRUE", "trUe"]),
-            (false, ["false", "FALSE", "faLse"]),
-            (nil, ["", "_true_", "_false_", "_yes_", "_no_", "_1_", "_0_", "11", "00"])
-        ]
-
-        for (expected, inputs) in cases {
-            for input in inputs {
-                #expect(bd.decodeBool(from: input) == expected, "input: \(input)")
-            }
-        }
-    }
-}
diff --git a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
index 2131cc8..1fa2f7f 100644
--- a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
+++ b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
@@ -68,6 +68,26 @@ struct EnvironmentVariablesProviderTests {
         #expect(provider.debugDescription == expectedDebugDescription)
     }
 
+    @Test()
+    @available(Configuration 1.0, *)
+    func decodeBoolFromString() throws {
+        let cases: [(expected: Bool?, input: [String])] = [
+            (true, ["1"]),
+            (false, ["0"]),
+            (true, ["Yes", "yes", "YES", "yES"]),
+            (false, ["No", "no", "NO", "nO"]),
+            (true, ["true", "TRUE", "trUe"]),
+            (false, ["false", "FALSE", "faLse"]),
+            (nil, ["", "_true_", "_false_", "_yes_", "_no_", "_1_", "_0_", "11", "00"])
+        ]
+
+        for (expected, inputs) in cases {
+            for input in inputs {
+                #expect(EnvironmentVariablesProvider.Snapshot.decodeBool(from: input) == expected, "input: \(input)")
+            }
+        }
+    }
+
     @available(Configuration 1.0, *)
     @Test func valueForKeyOfBoolAndBoolArrayTypes() throws {
         let ep = EnvironmentVariablesProvider(

From 8ad1813ed76d5e16bd9fafe81a7fc431d15b183c Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 14:04:32 +0100
Subject: [PATCH 09/12] Delete outdated comments

---
 .../EnvironmentVariables/EnvironmentVariablesProvider.swift   | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
index 08e2a72..5f5f327 100644
--- a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
+++ b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
@@ -179,7 +179,6 @@ public struct EnvironmentVariablesProvider: Sendable {
     /// - Parameters:
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
-    ///   - boolDecoder: The decoder used for converting string values to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     public init(
         secretsSpecifier: SecretsSpecifier<String, String> = .none,
@@ -215,7 +214,6 @@ public struct EnvironmentVariablesProvider: Sendable {
     ///   - environmentVariables: A dictionary of environment variable names and values.
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
-    ///   - boolDecoder: The decoder used for converting string to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     public init(
         environmentVariables: [String: String],
@@ -261,7 +259,6 @@ public struct EnvironmentVariablesProvider: Sendable {
     ///     - When `true`, if the file is missing, treats it as empty. Malformed files still throw an error.
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
-    ///   - boolDecoder: The decoder used for converting string values to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     /// - Throws: If the file is malformed, or if missing when allowMissing is `false`.
     public init(
@@ -290,7 +287,6 @@ public struct EnvironmentVariablesProvider: Sendable {
     ///   - fileSystem: The file system implementation to use.
     ///   - secretsSpecifier: Specifies which environment variables should be treated as secrets.
     ///   - bytesDecoder: The decoder used for converting string values to byte arrays.
-    ///   - boolDecoder: The decoder used for converting string values to bool values.
     ///   - arraySeparator: The character used to separate elements in array values.
     /// - Throws: If the file is malformed, or if missing when allowMissing is `false`.
     internal init(

From b4cda9ee1b8099e63ce042f9f349fa9935656234 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 14:13:37 +0100
Subject: [PATCH 10/12] Use sut for instances under test in tests

---
 .../EnvironmentVariablesProviderTests.swift   | 30 +++++++++----------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
index 1fa2f7f..a716423 100644
--- a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
+++ b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
@@ -71,6 +71,7 @@ struct EnvironmentVariablesProviderTests {
     @Test()
     @available(Configuration 1.0, *)
     func decodeBoolFromString() throws {
+        let sut = EnvironmentVariablesProvider.Snapshot.decodeBool
         let cases: [(expected: Bool?, input: [String])] = [
             (true, ["1"]),
             (false, ["0"]),
@@ -80,17 +81,16 @@ struct EnvironmentVariablesProviderTests {
             (false, ["false", "FALSE", "faLse"]),
             (nil, ["", "_true_", "_false_", "_yes_", "_no_", "_1_", "_0_", "11", "00"])
         ]
-
         for (expected, inputs) in cases {
             for input in inputs {
-                #expect(EnvironmentVariablesProvider.Snapshot.decodeBool(from: input) == expected, "input: \(input)")
+                #expect(sut(input) == expected, "input: \(input)")
             }
         }
     }
 
     @available(Configuration 1.0, *)
     @Test func valueForKeyOfBoolAndBoolArrayTypes() throws {
-        let ep = EnvironmentVariablesProvider(
+        let sut = EnvironmentVariablesProvider(
             environmentVariables: [
                 "BOOL_TRUE": "true",
                 "BOOL_FALSE": "false",
@@ -105,18 +105,18 @@ struct EnvironmentVariablesProviderTests {
                 "BOOLY_ARRAY_THROWS_1": "true,1,YESS",
                 "BOOLY_ARRAY_THROWS_2": "false,00,no",
             ])
-        #expect(try ep.value(forKey: "BOOL_TRUE", type: .bool).value == true)
-        #expect(try ep.value(forKey: "BOOL_FALSE", type: .bool).value == false)
-        #expect(try ep.value(forKey: "BOOL_1", type: .bool).value == true)
-        #expect(try ep.value(forKey: "BOOL_0", type: .bool).value == false)
-        #expect(try ep.value(forKey: "BOOL_YES", type: .bool).value == true)
-        #expect(try ep.value(forKey: "BOOL_NO", type: .bool).value == false)
-        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOL_THROWS_ERROR_EMPTY", type: .bool) }
-        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOL_THROWS_ERROR_NOT_BOOL_STRING", type: .bool) }
-        #expect(try ep.value(forKey: "BOOLY_ARRAY_TRUE", type: .boolArray).value == .init([true, true, true], isSecret: false))
-        #expect(try ep.value(forKey: "BOOLY_ARRAY_FALSE", type: .boolArray).value == .init([false, false, false], isSecret: false))
-        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOLY_ARRAY_THROWS_1", type: .boolArray) }
-        #expect(throws: ConfigError.self) { try ep.value(forKey: "BOOLY_ARRAY_THROWS_2", type: .boolArray) }
+        #expect(try sut.value(forKey: "BOOL_TRUE", type: .bool).value == true)
+        #expect(try sut.value(forKey: "BOOL_FALSE", type: .bool).value == false)
+        #expect(try sut.value(forKey: "BOOL_1", type: .bool).value == true)
+        #expect(try sut.value(forKey: "BOOL_0", type: .bool).value == false)
+        #expect(try sut.value(forKey: "BOOL_YES", type: .bool).value == true)
+        #expect(try sut.value(forKey: "BOOL_NO", type: .bool).value == false)
+        #expect(throws: ConfigError.self) { try sut.value(forKey: "BOOL_THROWS_ERROR_EMPTY", type: .bool) }
+        #expect(throws: ConfigError.self) { try sut.value(forKey: "BOOL_THROWS_ERROR_NOT_BOOL_STRING", type: .bool) }
+        #expect(try sut.value(forKey: "BOOLY_ARRAY_TRUE", type: .boolArray).value == .init([true, true, true], isSecret: false))
+        #expect(try sut.value(forKey: "BOOLY_ARRAY_FALSE", type: .boolArray).value == .init([false, false, false], isSecret: false))
+        #expect(throws: ConfigError.self) { try sut.value(forKey: "BOOLY_ARRAY_THROWS_1", type: .boolArray) }
+        #expect(throws: ConfigError.self) { try sut.value(forKey: "BOOLY_ARRAY_THROWS_2", type: .boolArray) }
     }
 
     @available(Configuration 1.0, *)

From e851e094e23889cee7349f9d33e5f351858afc62 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 19:09:19 +0100
Subject: [PATCH 11/12] Update
 Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift

Use a compact switch-based implementation for decodeBool.

Co-authored-by: Honza Dvorsky <honza@apple.com>
---
 .../EnvironmentVariablesProvider.swift              | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
index 5f5f327..829b98e 100644
--- a/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
+++ b/Sources/Configuration/Providers/EnvironmentVariables/EnvironmentVariablesProvider.swift
@@ -145,15 +145,10 @@ public struct EnvironmentVariablesProvider: Sendable {
 
         /// A decoder of bool values from a string
         static func decodeBool(from string: String) -> Bool? {
-            let stringLowercased = string.lowercased()
-            return if ["true", "false"].contains(stringLowercased) {
-                stringLowercased == "true"
-            } else if ["yes", "no"].contains(stringLowercased) {
-                stringLowercased == "yes"
-            } else if ["1", "0"].contains(stringLowercased) {
-                stringLowercased == "1"
-            } else {
-                nil
+            switch string.lowercased() {
+            case "true", "yes", "1": true
+            case "false", "no", "0": false
+            default: nil
             }
         }
     }

From a99f74538e5ba0e453c141bce458494890e68e26 Mon Sep 17 00:00:00 2001
From: Blazej SLEBODA <5544365+Adobels@users.noreply.github.com>
Date: Wed, 17 Dec 2025 19:11:29 +0100
Subject: [PATCH 12/12] Update
 Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift

Fix the order of macros used in a test case to align with the test target order.

Co-authored-by: Honza Dvorsky <honza@apple.com>
---
 .../ConfigurationTests/EnvironmentVariablesProviderTests.swift | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
index a716423..fb15ff8 100644
--- a/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
+++ b/Tests/ConfigurationTests/EnvironmentVariablesProviderTests.swift
@@ -68,9 +68,8 @@ struct EnvironmentVariablesProviderTests {
         #expect(provider.debugDescription == expectedDebugDescription)
     }
 
-    @Test()
     @available(Configuration 1.0, *)
-    func decodeBoolFromString() throws {
+    @Test func decodeBoolFromString() throws {
         let sut = EnvironmentVariablesProvider.Snapshot.decodeBool
         let cases: [(expected: Bool?, input: [String])] = [
             (true, ["1"]),