feat: support MCP-as-CLI progress messages on stderr

[Copilot]

Summary

• update actions/setup/js/mcp_cli_bridge.cjs to parse streamed JSON-RPC/SSE message payloads
• detect MCP notifications/progress events and emit progress output to stderr
• preserve existing final result/error rendering by selecting terminal result/error messages from the stream
• add targeted unit tests for message-based and numeric progress notifications

Validation

• cd /home/runner/work/gh-aw/gh-aw/actions/setup/js && npm run lint:cjs
• cd /home/runner/work/gh-aw/gh-aw/actions/setup/js && npx vitest run mcp_cli_bridge.test.cjs
• cd /home/runner/work/gh-aw/gh-aw && make agent-finish (fails in existing unrelated pkg/workflow tests: TestCopilotDetectionDefaultModel, TestWasmGolden_CompileFixtures)
• parallel_validation (Code Review: no comments; CodeQL: no alerts reported)

[github-actions]

🧪 Test Quality Sentinel Report

Test Quality Score: 85/100

✅ Excellent test quality

Metric	Value
New/modified tests analyzed	2
✅ Design tests (behavioral contracts)	2 (100%)
⚠️ Implementation tests (low value)	0 (0%)
Tests with error/edge cases	1 (50%)
Duplicate test clusters	0
Test inflation detected	No
🚨 Coding-guideline violations	None

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Test Classification Details

Test	File	Classification	Issues Detected
prints progress notifications to stderr and final text result to stdout for SSE responses	actions/setup/js/mcp_cli_bridge.test.cjs	✅ Design	None
prints numeric progress to stderr when progress notification has no message	actions/setup/js/mcp_cli_bridge.test.cjs	✅ Design (edge case)	None

i️ The Go change in pkg/cli/spec_test.go is purely a struct field alignment/rename fix — no new test functions were added, so it is not scored.

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Test Analysis Notes

prints progress notifications to stderr and final text result to stdout for SSE responses
Verifies the behavioral contract for SSE progress notifications: that a notifications/progress message with a message field is written to stderr, and the final tool result text goes to stdout with exit code 0. This is a direct behavioral test of the new feature.

prints numeric progress to stderr when progress notification has no message
Covers the edge case where a progress notification omits the message field — the system should fall back to "Progress: N/M" formatting. Verifies both the fallback formatting on stderr and that the result still routes correctly to stdout. Good edge case coverage.

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Scoring Breakdown

Component	Score
Behavioral Coverage (2/2 design tests × 40)	40/40
Error/Edge Case Coverage (1/2 tests × 30)	15/30
Low Duplication (0 duplicate clusters)	20/20
Proportional Growth (test +24 lines, prod +118 lines → ratio 0.2:1)	10/10
Total	85/100

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Language Support

Tests analyzed:

• 🟨 JavaScript (*.test.cjs): 2 tests (vitest) — mcp_cli_bridge.test.cjs
• 🐹 Go (*_test.go): 0 new tests (only struct formatting change in spec_test.go)

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Verdict

✅ Check passed. 0% of new tests are implementation tests (threshold: 30%). Both new tests verify observable behavioral contracts — stderr output content, stdout output content, and process exit codes — for the new MCP-as-CLI progress message feature.

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📖 Understanding Test Classifications

Design Tests (High Value) verify what the system does:

• Assert on observable outputs, return values, or state changes
• Cover error paths and boundary conditions
• Would catch a behavioral regression if deleted
• Remain valid even after internal refactoring

Implementation Tests (Low Value) verify how the system does it:

• Assert on internal function calls (mocking internals)
• Only test the happy path with typical inputs
• Break during legitimate refactoring even when behavior is correct
• Give false assurance: they pass even when the system is wrong

Goal: Shift toward tests that describe the system's behavioral contract — the promises it makes to its users and collaborators.

References: §24841780742

🧪 Test quality analysis by Test Quality Sentinel · ● 346.2K · ◷

[github-actions]

✅ Test Quality Sentinel: 85/100. Test quality is excellent — 0% of new tests are implementation tests (threshold: 30%). Both new JavaScript tests verify observable behavioral contracts for the MCP-as-CLI progress message feature.