fix: stop solveUntilPhase when solver reaches terminal state (#267)

[iprasen]

Summary

Fixes an infinite loop in LayoutPipelineSolver.solveUntilPhase(phase: string) when the solver reaches a terminal state (solved or failed) before reaching the target phase.

Root Cause

In lib/solvers/LayoutPipelineSolver/LayoutPipelineSolver.ts:

solveUntilPhase(phase: string) {
  while (this.getCurrentPhase() !== phase) {
    this.step()
  }
}

BaseSolver.step() immediately returns when this.solved || this.failed. If phase is unknown, already passed, or if an intermediate phase fails or completes the pipeline without matching phase, step() becomes a no-op that never advances currentPipelineStepIndex. The loop condition this.getCurrentPhase() !== phase remains true indefinitely, blocking the runtime thread.

Solution

Mirror the terminal-state guards from BaseSolver.solve():

solveUntilPhase(phase: string) {
  while (!this.solved && !this.failed && this.getCurrentPhase() !== phase) {
    this.step()
  }
}

Verification

• Added comprehensive regression test suite in tests/LayoutPipelineSolver/solveUntilPhase-terminal.test.ts with 11 targeted test cases:
  1. Already at target phase: exits immediately without extra steps
  2. Real fixture: cleanly reaches intermediate phase
  3. Pre-failed solver: preserves failure without calling step
  4. Pre-solved solver: does not step for unmet target
  5. Failed active subsolver: halts and preserves subsolver error
  6. Iteration budget exhaustion: terminates promptly instead of spinning
  7. Unknown target phase: safely terminates when solver completes
  8. Requesting an already-passed phase: returns safely
  9. none sentinel: preserves stopping before final step
  10. Thrown child exceptions: correctly propagates errors
  11. Staged solve equivalence: staged execution matches direct solve() output
• Full repository test suite passes (11/11 new tests passing).
• bun x --no-install tsc --noEmit: 0 errors.
• bun run format:check: clean.
• bun run build: clean ESM + DTS output.

Closes #267

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Project	Deployment	Actions	Updated
matchpack	Ready	Preview	Sep 18, 2026 5:59pm UTC