Add support for Ballerina Interpreter v0.5.0

[snelusha]

Introduce PAL including proper stdout, stderr handling and HTTP support with fetch API.
Resolves #15

Summary by CodeRabbit

• New Features

  • Added browser-compatible HTTP client for WASM execution
  • Enhanced diagnostic messages with improved location and source formatting

• Bug Fixes

  • Fixed Node.js process hanging due to uncleared WASM timers

• Chores

  • Updated dependencies
  • Improved project loading mechanism

[coderabbitai]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 39d7bed4-f289-4bd6-913d-68f857f39ee5

📥 Commits

Reviewing files that changed from the base of the PR and between 5266da1 and 4fc2805.

📒 Files selected for processing (1)

• packages/ballerina-wasm/pal_wasm.go

📝 Walkthrough

Walkthrough

This PR refactors the Ballerina WASM runtime to load projects via projects.Load, introduces diagnostic environment awareness for better error reporting, adds a browser-based HTTP client using JavaScript fetch, and improves the Node.js WASM bridge to prevent process hangs from lingering Go timers.

Changes

Ballerina WASM Runtime and Platform Refactoring

Layer / File(s)	Summary
Diagnostic Environment and Location Handling packages/ballerina-wasm/diagnostic_printer.go	printDiagnostics now accepts and passes *diagnostics.DiagnosticEnv to each diagnostic; printDiagnostic replaces nil-location checks with empty-location semantics and uses environment-derived getters for file name and line/column coordinates.
Project Loading and Diagnostics Integration packages/ballerina-wasm/ballerina-lang-go, packages/ballerina-wasm/main_wasm.go, packages/ballerina-wasm/go.mod	Main entrypoint switches from directory.LoadProject to projects.Load, creates and wires diagnostics.NewDiagnosticEnv() into diagnostic printing; imports updated for runtime and diagnostics tools; subproject updated to new commit; go.mod adds github.com/cockroachdb/apd/v3 indirect dependency.
Browser HTTP Client with Fetch packages/ballerina-wasm/pal_wasm.go	New fetchHTTPClient implementation using JavaScript fetch API, constructs fetch options with method/headers/redirect/body/timeout, extracts response status/headers/body via JS callbacks, and newPal wires the client into pal.Platform with stdout/stderr writers.
Runtime Initialization with PAL and Type Environment packages/ballerina-wasm/main_wasm.go	Runtime now created with newPal(stdout, stderr) and project's type environment instead of no-arg constructor; stdout defaults to os.Stdout when not provided; capturePrintlnOutput helper removed.

Node.js WASM Bridge Timeout Management

Layer / File(s)	Summary
Go Runtime Lifetime Management and Timeout Cleanup packages/balrun/src/wasm-bridge.ts, packages/balrun/package.json	WasmBridge stores Go runtime instance during load and clears scheduled timeouts in a finally block after each run via new clearScheduledTimeouts method, preventing internal _scheduledTimeouts from keeping Node alive; unrun added to devDependencies.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related PRs

• snelusha/balrun#16: Establishes the initial WASM bridge implementation that this PR extends with Go runtime cleanup logic.

Poem

🐰 The runtime hops with fetch so swift,
Diagnostics dance with env's gift,
No timers linger, no ghosts remain—
The bridge now breathes, released from chain!
✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately reflects the main objective of the pull request: upgrading support to Ballerina Interpreter v0.5.0. It directly corresponds to the source branch (chore/v0.5.0) and the substantial changes across multiple files for this upgrade.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch chore/v0.5.0

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[coderabbitai]

🧹 Nitpick comments (1)

packages/ballerina-wasm/pal_wasm.go (1)

52-72: 💤 Low value

Silent fallback when AbortController is unavailable.

If setupTimeout fails (e.g., AbortController not available in the environment), the error is silently ignored and the request proceeds without timeout protection. Consider logging or returning an error to make this behavior explicit.

🤖 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 `@packages/ballerina-wasm/pal_wasm.go` around lines 52 - 72, The
buildFetchOptions function currently swallows setupTimeout errors (e.g., missing
AbortController) which results in silent no-timeout requests; change
buildFetchOptions to surface that failure by returning (map[string]any, error)
instead of just map[string]any, call setupTimeout and if it errors return the
partially built options with the error (or nil options with the error) so
callers can decide, or alternatively log the error explicitly (using the
client's logger on fetchHTTPClient) before proceeding; update all callers of
buildFetchOptions (e.g., the HTTP request entrypoint that invokes
buildFetchOptions) to handle the new error return and either abort or proceed
with explicit warning so the lack of timeout is not silent.

🤖 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.

Nitpick comments:
In `@packages/ballerina-wasm/pal_wasm.go`:
- Around line 52-72: The buildFetchOptions function currently swallows
setupTimeout errors (e.g., missing AbortController) which results in silent
no-timeout requests; change buildFetchOptions to surface that failure by
returning (map[string]any, error) instead of just map[string]any, call
setupTimeout and if it errors return the partially built options with the error
(or nil options with the error) so callers can decide, or alternatively log the
error explicitly (using the client's logger on fetchHTTPClient) before
proceeding; update all callers of buildFetchOptions (e.g., the HTTP request
entrypoint that invokes buildFetchOptions) to handle the new error return and
either abort or proceed with explicit warning so the lack of timeout is not
silent.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: f99a1b66-e267-4945-b3ec-3d20696bd2e2

📥 Commits

Reviewing files that changed from the base of the PR and between 2d9bdc3 and 5266da1.

⛔ Files ignored due to path filters (2)

• bun.lock is excluded by !**/*.lock
• packages/ballerina-wasm/go.sum is excluded by !**/*.sum

📒 Files selected for processing (7)

• packages/ballerina-wasm/ballerina-lang-go
• packages/ballerina-wasm/diagnostic_printer.go
• packages/ballerina-wasm/go.mod
• packages/ballerina-wasm/main_wasm.go
• packages/ballerina-wasm/pal_wasm.go
• packages/balrun/package.json
• packages/balrun/src/wasm-bridge.ts