Support edge labels for one-to-one and through relations 🩷

[kingrubic]

Summary

• preserve existing OneToOneField metadata labels in the ER diagram
• parse ManyToManyField through= arguments and include the intermediate model in edge labels
• add a regression test covering both relation types

Tests

• npm test
• npm run build
• npm run package -- --out /tmp/django-orm-lens-issue-2.vsix
• git diff --check

Closes #2

Summary by CodeRabbit

• New Features
  • Mermaid relationship diagrams now include intermediary (“through”) model details for many-to-many relationships.
  • Relationship edge labels now surface additional metadata such as cascade behavior, related names, and through-model information.
• Bug Fixes
  • Improved Django relationship parsing so generated diagram connections better match configured model relationships.
• Tests
  • Added automated coverage to verify the generated edge labels include through-model and related metadata.
  • Added an npm test script to build the extension and run the Node test runner.

[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

test/edge-labels.test.js (1)

5-11: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Restore Module._load after the test to avoid global side effects.

The vscode mock replaces Module._load globally but never restores it. While node --test typically runs each file in its own process, restoring the original loader is good hygiene and prevents interference if test isolation changes.

♻️ Proposed fix

 const originalLoad = Module._load;
 Module._load = function (request, parent, isMain) {
   if (request === 'vscode') {
     return {};
   }
   return originalLoad.call(this, request, parent, isMain);
 };
+
+// Restore the original loader after all tests in this file complete.
+test.after(() => {
+  Module._load = originalLoad;
+});

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@test/edge-labels.test.js` around lines 5 - 11, Restore Module._load to
originalLoad after the test completes, ensuring the temporary vscode mock in the
Module._load override does not persist globally. Use the existing originalLoad
symbol and the test’s teardown mechanism rather than changing the mock behavior.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/parser.ts`:
- Around line 112-117: Update the regular expression in extractThroughModel to
require a word boundary immediately before “through”, preventing matches within
longer argument names while preserving the existing value-capture behavior.

---

Nitpick comments:
In `@test/edge-labels.test.js`:
- Around line 5-11: Restore Module._load to originalLoad after the test
completes, ensuring the temporary vscode mock in the Module._load override does
not persist globally. Use the existing originalLoad symbol and the test’s
teardown mechanism rather than changing the mock behavior.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 42da5480-f993-45a1-beac-3b80f1c70598

📥 Commits

Reviewing files that changed from the base of the PR and between 31fdfba and a479842.

📒 Files selected for processing (5)

• package.json
• src/graphWebview.ts
• src/parser.ts
• src/types.ts
• test/edge-labels.test.js

[FROWNINGdev]

Thanks for the contribution! The through-model handling with the \b boundary is exactly right (correctly ignores passthrough=), and the regression test covers both branches. Setting to auto-merge once the workflow completes.