[test-improver] Improve tests for launcher connection pool

[github-actions]

Test Improvements: connection_pool_test.go

File Analyzed

• Test File: internal/launcher/connection_pool_test.go
• Package: internal/launcher

Improvements Made

1. Increased Coverage

• ✅ Added TestConnectionPoolGet_ClosedState: covers the ConnectionStateClosed early-exit branch in SessionConnectionPool.Get() (lines 232–235 of connection_pool.go)

Function	Before	After
SessionConnectionPool.Get	86.7%	100.0%
Package total	96.5%	97.0%

2. Cleaner & More Stable Tests

• ✅ Follows the established direct-pool-manipulation pattern already used in TestCleanupIdleConnections_AlreadyClosedState — consistent with the rest of the file
• ✅ Deterministic: no timers, goroutines, or external dependencies
• ✅ Descriptive assertions with context messages

Test Execution

All tests pass:

=== RUN   TestConnectionPoolGet_ClosedState
--- PASS: TestConnectionPoolGet_ClosedState (0.00s)
PASS
ok  github.com/github/gh-aw-mcpg/internal/launcher  17.124s  coverage: 97.0% of statements

Why These Changes?

SessionConnectionPool.Get() had an untested branch: when a connection exists in the pool map but its State is ConnectionStateClosed, Get returns (nil, false) without removing the entry. This is the correct behaviour (cleanup is delegated to cleanupIdleConnections), but the branch was never exercised by tests.

The new test injects a closed-state entry directly into pool.connections (same technique as TestCleanupIdleConnections_AlreadyClosedState) and asserts that Get correctly signals "not found" while leaving the entry intact for the background cleanup pass.

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[Copilot]

Pull request overview

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Improves unit test coverage and stability for SessionConnectionPool.Get() by adding a deterministic test that exercises the “closed connection entry” early-exit path.

Changes:

• Added TestConnectionPoolGet_ClosedState to cover the ConnectionStateClosed branch in Get().
• Asserts that Get() returns (nil, false) and does not remove the closed entry (leaving cleanup to the idle cleanup path).

Show a summary per file

File	Description
internal/launcher/connection_pool_test.go	Adds a new unit test to cover the “closed-state entry exists in map” branch in SessionConnectionPool.Get().

Copilot's findings

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• Files reviewed: 1/1 changed files
• Comments generated: 2

[lpcox]

@copilot address review feedback

[Copilot]

@copilot address review feedback

Addressed in c76521f.

Updates made in TestConnectionPoolGet_ClosedState:

• switched to NewSessionConnectionPoolWithConfig with a long cleanup interval to keep the test deterministic
• used a single now := time.Now() for both CreatedAt and LastUsedAt
• changed lock usage to scoped defer pool.mu.Unlock() within a closure

Validation run: go test -v ./internal/launcher and make agent-finished both pass.