Need for improvement in error Handling Across the Project

[Keshav-poha]

Current Problems:
Missing null/undefined checks
Code assumes API responses are always well-formed
Users see technical errors or blank screens
One error breaks entire features

Here are examples of problematic code lines that fit each category:

Missing null/undefined checks

// script.js:L157-L159
if (data.results.length === 0) {
    showError('No results found for the given query.');
    return;

Issue: data.results could be undefined if API returns unexpected structure

// script.js:L293-L295
nodes.forEach(node => {
    const label = node.properties.name || node.properties.asn || node.id;
    const type = node.labels[0];

Issue: node.properties and node.labels could be undefined/empty

// script.js:L394-L396
relationships.forEach(rel => {
    const row = tbody.insertRow();
    row.insertCell(0).textContent = rel.type;

Issue: rel.type could be undefined

Code assumes API responses are always well-formed

// script.js:L161-L163
const nodes = data.results.flatMap(result => result.nodes);
const relationships = data.results.flatMap(result => result.relationships);
storeData(nodes, relationships);

Issue: Assumes result.nodes and result.relationships always exist

// script.js:L466-L468
.then(response => response.json())
.then(data => {
    const newNodes = data.results.flatMap(result => result.nodes);

Issue: No validation that response contains expected structure

// script.js:L207-L209
function storeData(nodes, relationships) {
    nodes.forEach(node => {
        if (!allNodes.has(node.id)) {

Issue: Assumes node.id always exists

Users see technical errors or blank screens

// script.js:L511-L513
.catch(error => {
    console.error('Error expanding node:', error);
    showError('Failed to expand node: ' + error.message);

Issue: Shows raw error.message to users (technical details)

// script.js:L488-L490
.catch(error => {
    console.error('Error fetching data:', error);
    showError('Failed to fetch data: ' + error.message);

Issue: Technical error message exposed to users

One error breaks entire features

// script.js:L293-L300
nodes.forEach(node => {
    const label = node.properties.name || node.properties.asn || node.id;
    const type = node.labels[0];
    if (selectedNodeTypes.size === 0 || selectedNodeTypes.has(type)) {
        const nodeElement = svg.append('circle')
            .attr('r', 10)
            .attr('fill', getNodeColor(type))
            .attr('stroke', '#fff')

Issue: If one node has malformed data, the entire forEach fails and no graph renders

// script.js:L161-L166
const nodes = data.results.flatMap(result => result.nodes);
const relationships = data.results.flatMap(result => result.relationships);
storeData(nodes, relationships);
renderGraph();
renderTable();

Issue: If storeData() throws error, both renderGraph() and renderTable() never execute

[Keshav-poha]

these are few of the many examples I found, one important one has the consequence that a the blank page shows because of lack
of user-sided error messages, example- https://iyp.iijlab.net/browser/embed

[Keshav-poha]

I would like to contribute towards this optimization.

[dpgiakatos]

I don't expect the user to access https://iyp.iijlab.net/browser/embed, as it's impossible to navigate through the tool in that manner. Have you tried reproducing the issues you described? Each issue should include steps for reproduction, along with screenshots and detailed instructions; otherwise, they remain hypotheses.

Have you reviewed the connector code between Neo4j and the tool? Additionally, have you attempted to return nodes with null properties? I do not consider this an issue until you provide clear evidence that the problems you've described actually exist. This is how issues should be reported.

Please note that our organization has a strict AI policy for potential GSoC contributors. If you are interested in GSoC, I assume you have already read our GSoC repository before starting to contribute and open issues. I can sense from your message that you are using an AI tool, as you consistently reference a script.js file, which does not exist in this repository.

[Keshav-poha]

Hey! so yes i reproduce all of my submitted issues (you can see in my previously raised issues), But since there were so many error handling issues in the project, which would mostly classified as improvement rather than bugs, Hence why i mentioned "improvement" and "optimization" in my issue message.

i have recreated one of them here by imitating network errors, cors errors and timeout errors by block the API, which shows an ever loading result, rather than an immediate user-end error message.

I still think recreating all the error handling in the project isnt necessary in one single issue as its pretty clear that, i suggested improvements/optimizations rather than bugs.

Yes, i have read the code, and attempted to recreate some of the bugs (not all)
I will keep your words in mind next time i report an issue.

Also, Thanks for telling me about GSoC opportunity, I would surely look forward to it and apply for myself, and as a requirement, I would disclose any Ai usage from now on, (i was not going for gsoc before that is why i had no idea i had to disclose Ai usage)
my first disclosure- I do use an LLM which read all the VUE codes as a single script.js file, it helped me write this issue message, but i can assure you i edit and read the code for issues with the best of my OWN abilities.

I apologize if i had broken any code of conduct unknowingly

[Keshav-poha]

As for the https://iyp.iijlab.net/browser/embed, the blank page being changed to a clear error message would be an improvement as it would make the jobs easier for developers willing to add this embed onto their websites, a good error message will lead them to correct urls,
for example https://iyp.iijlab.net/browser/embed?session=W3sicXVlcnkiOiJNQVRDSCAobikgUkVUVVJOIG4gTElNSVQgMTAifV0=&showGraphOverview=true)

if any of the query is missing, or wrong , instead of an error message it shows a white page (crash)

[Rutuja123-dos]

Hi, I’m a student contributor interested in gsoc and improving frontend robustness.
I’d like to start by adding null/undefined checks and improving error handling
in the areas mentioned above. Please let me know if I can proceed.