chore: check generated snapshots

.github/workflows/ci.yml

@@ -86,6 +86,15 @@ jobs:
         run: |
           rustup toolchain install ${{ matrix.rust-version }}
           rustup default ${{ matrix.rust-version }}
+      - uses: actions/setup-go@v6
+        with:
+          go-version: stable
+          cache-dependency-path: |
+            tools/snapshots/go/go.sum
+      - name: Generate test snapshots
+        shell: bash
+        working-directory: tools/snapshots/go
+        run: go test -v ./...
       - name: Build
         run: cargo build --workspace --all-features --bins --tests --examples --benches --lib
       - name: Run unit tests

tests/hll_serialization_test.rs

@@ -18,8 +18,10 @@
 //! HLL Sketch Serialization Compatibility Tests
 //!
 //! These tests verify binary compatibility with Apache DataSketches implementations:
+//!
 //! - Java (datasketches-java)
 //! - C++ (datasketches-cpp)
+//! - Go (datasketches-go)
 //!
 //! Test data is generated by the reference implementations and stored in:
 //! `tests/serialization_test_data/`
@@ -41,7 +43,16 @@ fn get_test_data_path(sub_dir: &str, name: &str) -> PathBuf {
 fn test_sketch_file(path: PathBuf, expected_cardinality: usize, expected_lg_k: u8) {
     let expected = expected_cardinality as f64;
 
-    let bytes = fs::read(&path).unwrap();
+    let bytes = match fs::read(&path) {
+        Ok(bytes) => bytes,
+        Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
+            panic!(
+                "snapshot {} not found; generate it with ...",
+                path.display()
+            );
+        }
+        Err(err) => panic!("failed to read test data file {}: {}", path.display(), err),
+    };
     let sketch1 = HllSketch::deserialize(&bytes).unwrap();
     let estimate1 = sketch1.estimate();
 
@@ -177,6 +188,39 @@ fn test_cpp_hll8_compatibility() {
     }
 }
 
+#[test]
+fn test_go_hll4_compatibility() {
+    let test_cases = [0, 1, 10, 100, 1000, 10000, 100000, 1000000];
+
+    for n in test_cases {
+        let filename = format!("hll4_n{}_go.sk", n);
+        let path = get_test_data_path("go_generated_files", &filename);
+        test_sketch_file(path, n, 12);
+    }
+}
+
+#[test]
+fn test_go_hll6_compatibility() {
+    let test_cases = [0, 1, 10, 100, 1000, 10000, 100000, 1000000];
+
+    for n in test_cases {
+        let filename = format!("hll6_n{}_go.sk", n);
+        let path = get_test_data_path("go_generated_files", &filename);
+        test_sketch_file(path, n, 12);
+    }
+}
+
+#[test]
+fn test_go_hll8_compatibility() {
+    let test_cases = [0, 1, 10, 100, 1000, 10000, 100000, 1000000];
+
+    for n in test_cases {
+        let filename = format!("hll8_n{}_go.sk", n);
+        let path = get_test_data_path("go_generated_files", &filename);
+        test_sketch_file(path, n, 12);
+    }
+}
+
 #[test]
 fn test_estimate_accuracy() {
     // This test verifies and prints actual estimates to show accuracy

tests/serialization_test_data/go_generated_files/.gitignore

@@ -0,0 +1 @@
+*.sk

tools/snapshots/go/go.mod

@@ -0,0 +1,15 @@
+module datasketches.apache.org/tools
+
+go 1.25.5
+
+require (
+	github.com/apache/datasketches-go v0.0.0-20251212084617-f7bc4b1db865
+	github.com/stretchr/testify v1.11.1
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/twmb/murmur3 v1.1.8 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

tools/snapshots/go/go.sum

@@ -0,0 +1,14 @@
+github.com/apache/datasketches-go v0.0.0-20251212084617-f7bc4b1db865 h1:C8vuEhEBC2udZqWnx40Li2JkDw0NRyqJDycjedrauLw=
+github.com/apache/datasketches-go v0.0.0-20251212084617-f7bc4b1db865/go.mod h1:tWCpdsIfpbCQH04ZV3mUb6RyIfovjjNwHn/dGT8wrTw=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+github.com/twmb/murmur3 v1.1.8 h1:8Yt9taO/WN3l08xErzjeschgZU2QSrwm1kclYq+0aRg=
+github.com/twmb/murmur3 v1.1.8/go.mod h1:Qq/R7NUyOfr65zD+6Q5IHKsJLwP7exErjN6lyyq3OSQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

tools/snapshots/go/tools_test.go

@@ -0,0 +1,54 @@
+package tools
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/apache/datasketches-go/hll"
+	"github.com/stretchr/testify/require"
+)
+
+const defaultLgK = 12
+
+func TestGenerateGoFile(t *testing.T) {
+	path, err := os.Getwd()
+	require.NoError(t, err)
+
+	workspace := filepath.Join(path, "..", "..", "..")
+	target := filepath.Join(workspace, "tests", "serialization_test_data", "go_generated_files")
+
+	nArr := []int{0, 1, 10, 100, 1000, 10000, 100000, 1000000}
+	for _, n := range nArr {
+		hll4, err := hll.NewHllSketch(defaultLgK, hll.TgtHllTypeHll4)
+		require.NoError(t, err)
+		hll6, err := hll.NewHllSketch(defaultLgK, hll.TgtHllTypeHll6)
+		require.NoError(t, err)
+		hll8, err := hll.NewHllSketch(defaultLgK, hll.TgtHllTypeHll8)
+		require.NoError(t, err)
+
+		for i := 0; i < n; i++ {
+			require.NoError(t, hll4.UpdateUInt64(uint64(i)))
+			require.NoError(t, hll6.UpdateUInt64(uint64(i)))
+			require.NoError(t, hll8.UpdateUInt64(uint64(i)))
+		}
+		err = os.MkdirAll(target, os.ModePerm)
+		require.NoError(t, err)
+
+		sl4, err := hll4.ToCompactSlice()
+		require.NoError(t, err)
+		err = os.WriteFile(fmt.Sprintf("%s/hll4_n%d_go.sk", target, n), sl4, 0644)
+		require.NoError(t, err)
+
+		sl6, err := hll6.ToCompactSlice()
+		require.NoError(t, err)
+		err = os.WriteFile(fmt.Sprintf("%s/hll6_n%d_go.sk", target, n), sl6, 0644)
+		require.NoError(t, err)
+
+		sl8, err := hll8.ToCompactSlice()
+		require.NoError(t, err)
+		err = os.WriteFile(fmt.Sprintf("%s/hll8_n%d_go.sk", target, n), sl8, 0644)
+		require.NoError(t, err)
+	}
+}