running-tests

name	running-tests
audience	swarm-plugin
description	Safe test execution patterns for opencode-swarm. Covers when to use the test_runner tool vs shell bun commands, scope safety rules, per-file isolation loops (bash and PowerShell), pre-existing failure verification, CI log reading, and failure classification. Load this skill when you need to run tests — not when you need to write them (see writing-tests for authoring guidance).

Running Tests for opencode-swarm

This skill is about executing tests safely. For writing tests, see writing-tests.

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⛔ The One Rule That Prevents Session Kills

Never use test_runner with more than one source file for any discovery scope.

graph and impact each fan out per file through the import tree; convention maps each source file to a test file by name convention. The union quickly exceeds MAX_SAFE_TEST_FILES = 50, triggering scope_exceeded, which causes LLMs to cascade to scope: 'all' and kill the session. All three scopes now reject with scope_exceeded before fan-out when sourceFiles.length > MAX_SAFE_SOURCE_FILES = 1.

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Three-Layer Defense Against Session Blocking

test_runner has three pre-resolution guards that prevent unbounded fan-out from blocking the session:

Layer 1 — Source-file count guard (synchronous, fires before any I/O)

sourceFiles.length > MAX_SAFE_SOURCE_FILES (1) → returns scope_exceeded immediately. Catches the common case of multi-file calls before any filesystem access.

Layer 2 — Pre-resolution fan-out estimate (fast, ~100ms)

estimateFanOut(sourceFiles, workingDir) reads the cached impact map and counts unique test files without spawning subprocesses. If the estimate exceeds MAX_SAFE_TEST_FILES = 50, the call returns scope_exceeded immediately — before any graph traversal begins. Only fires when sourceFiles.length === 1 (Layer 1 has already passed).

Layer 3 — Budget-limited traversal + post-resolution length check

analyzeImpact accepts a budget parameter (MAX_SAFE_TEST_FILES = 50). The traversal stops as soon as it has visited 50 test files and sets budgetExceeded: true. The call site checks this flag and returns scope_exceeded before processing results. After graph resolution, the final testFiles.length is additionally compared to MAX_SAFE_TEST_FILES. If exceeded, scope_exceeded is returned.

Result: When fan-out exceeds the safe threshold, the session gets outcome: 'scope_exceeded' instead of hanging.

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Decision Tree: test_runner tool vs bun shell command

Do you need to run tests?
│
├─ Single test file, targeted validation
│   └─ Either works. Prefer shell: bun --smol test <file> --timeout 30000
│
├─ Multiple files in the same directory (e.g. all agents tests)
│   └─ Shell only — per-file loop. Never test_runner with multiple files.
│
├─ Find tests related to ONE changed source file
│   └─ test_runner is fine: { scope: 'graph', files: ['src/agents/coder.ts'] }
│      (single file → bounded fan-out)
│
├─ Find tests related to MULTIPLE changed source files
│   └─ Shell only — per-file loop over the changed files, or run the whole directory.
│      test_runner with any discovery scope + multiple source files = scope_exceeded
│      (guard fires before fan-out for convention, graph, and impact scopes).
│
└─ Validate the entire repo (pre-push)
    └─ Shell only — 5-tier suite from commit-pr skill. Never test_runner scope:'all'.

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Scope Safety Reference

Scope	With files: [one]	With files: [many]	Notes
'convention'	✅ Safe	❌ Rejected (scope_exceeded)	Guard fires before fan-out; direct test file paths exempt
'graph'	✅ Safe (capped at 50 via budget)	❌ Rejected (scope_exceeded)	Two-layer guard: source-file count + fan-out estimate
'impact'	✅ Safe (capped at 50 via budget)	❌ Rejected (scope_exceeded)	Two-layer guard: source-file count + fan-out estimate
'all'	❌ Never	❌ Never	Env-gated (SWARM_ALLOW_FULL_SUITE=1); CI mirror only

Rule of thumb: Pass exactly one source file to test_runner. For multiple files, use a shell loop.

For one named Go or CTest test, bypass file discovery with an exact native selector:

• Go: { scope: "target", native_target: { framework: "go-test", name: "TestName[/Subtest]", path: "relative/package" } }
• CTest: { scope: "target", native_target: { framework: "ctest", name: "ExactTestName", path: "relative/build-dir" } }

The target name is treated literally, the directory must stay within the project root, and the runner never falls back to a broader package or build-tree sweep.

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Per-File Isolation Loops

CI runs agents/tools/services in per-file isolation (one bun --smol process per file). Reproduce this locally with the following loops.

bash (Linux / macOS)

# Single directory — per-file isolation
for f in tests/unit/agents/*.test.ts; do
  bun --smol test "$f" --timeout 30000
done

# Multiple directories
for dir in tests/unit/tools tests/unit/services tests/unit/agents; do
  for f in "$dir"/*.test.ts; do
    bun --smol test "$f" --timeout 30000
  done
done

# Stop on first failure (useful for debugging)
for f in tests/unit/agents/*.test.ts; do
  bun --smol test "$f" --timeout 30000 || { echo "FAILED: $f"; break; }
done

PowerShell (Windows)

# Single directory — per-file isolation
Get-ChildItem tests/unit/agents/*.test.ts | ForEach-Object {
  bun --smol test $_.FullName --timeout 30000
}

# Multiple directories
@('tests/unit/tools', 'tests/unit/services', 'tests/unit/agents') | ForEach-Object {
  Get-ChildItem "$_/*.test.ts" | ForEach-Object {
    bun --smol test $_.FullName --timeout 30000
  }
}

# Capture output (avoids truncation on large output)
Get-ChildItem tests/unit/agents/*.test.ts | ForEach-Object {
  bun --smol test $_.FullName --timeout 30000
} | Out-File "$env:TEMP\test_out.txt"
Get-Content "$env:TEMP\test_out.txt" | Select-Object -Last 50

Common PowerShell pitfalls:

• for f in ...; do — invalid, use Get-ChildItem | ForEach-Object
• Select-String -Last N — invalid parameter, use Select-Object -Last N
• 2>&1 2>&1 — duplicate redirection, causes parse error; use 2>&1 once
• && — not supported in PowerShell 5.1; use ; if ($?) { cmd2 } instead
• bun test --exec bash — fails on Windows hosts with ENOENT (bash is not available in standard PowerShell). Use bun test directly or a PowerShell-based loop instead.
• After bun install --frozen-lockfile --force, non-elevated Windows shells can hit EPERM while reading refreshed node_modules entries. Treat that as a host permission/access issue: rerun the same focused Bun command with approved/elevated access before diagnosing it as a code or test failure.

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Batch vs Per-File: Which Directories Need Isolation?

Directory	Mode	Reason
tests/unit/tools/	Per-file loop	Heavy mock.module usage; cache poisoning risk
tests/unit/services/	Per-file loop	Same
tests/unit/agents/	Per-file loop	Same
tests/unit/hooks/	Per-file loop	Same
tests/unit/cli/	Batch OK	Fewer mock conflicts
tests/unit/commands/	Batch OK	Fewer mock conflicts
tests/unit/config/	Batch OK	Fewer mock conflicts
tests/integration/	Batch OK	Integration fixtures, not mock-heavy
tests/security/	Batch OK	Adversarial inputs, no module mocks
tests/smoke/	Batch OK	Built-package tests

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Truncated Output Recovery

When bun test output exceeds the bash tool's buffer, it is saved to a file with an ID like tool_dff778.... This ID format is not accepted by retrieve_summary (which only reads S1, S2 etc. format IDs). The output is effectively lost.

Prevention — pipe to a file explicitly:

# PowerShell
bun --smol test tests/unit/agents --timeout 60000 |
  Out-File "$env:TEMP\test_out.txt"
Get-Content "$env:TEMP\test_out.txt" | Select-Object -Last 50

# bash
bun --smol test tests/unit/agents --timeout 60000 2>&1 | tee /tmp/test_out.txt
tail -50 /tmp/test_out.txt

To get a clean pass/fail summary only, filter immediately:

# PowerShell — show only summary lines
bun --smol test tests/unit/agents --timeout 60000 |
  Select-String "pass|fail|error" |
  Select-Object -Last 10

# bash
bun --smol test tests/unit/agents --timeout 60000 2>&1 | grep -E "pass|fail|error" | tail -10

---

Verifying Pre-Existing Failures

Before documenting a failure as "pre-existing," prove it exists on main without affecting your working tree. Use a Git worktree — safer than git stash (stash can drop untracked files, fail on locked files on Windows, and leave you in an inconsistent state).

# bash — create a throwaway checkout of main
git worktree add /tmp/repro-check origin/main
bun --smol test /tmp/repro-check/tests/unit/agents/architect-workflow-security.test.ts --timeout 30000
git worktree remove /tmp/repro-check

# PowerShell — same pattern (use Join-Path for robust separator handling)
git worktree add "$env:TEMP\repro-check" origin/main
$testPath = Join-Path "$env:TEMP\repro-check" "tests\unit\agents\architect-workflow-security.test.ts"
bun --smol test $testPath --timeout 30000
git worktree remove "$env:TEMP\repro-check"

Decision after checking:

• Fails on main too → pre-existing. Document under ## Pre-existing failures in PR body. Continue.
• Fails only on your branch → you introduced it. Fix before pushing.

⚠️ Check your own session history first. Before documenting anything as pre-existing, confirm you did not fix or update this test earlier in the current session. A test you fixed 20 messages ago is not pre-existing — listing it as such in the table or PR body is incorrect and will be caught in review.

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Failure Classification

Not all failures are equal. Before deciding what to do, classify the failure:

Class	Definition	Example	What to do
Stale assertion	Test checks for text/value that was deliberately removed	expect(prompt).toContain('CONSTRAINT: [what NOT to do]') — template removed in refactor	Update the assertion to match current state
Soft regression indicator	Test checks a threshold the codebase has since exceeded	expect(tokenCount).toBeLessThan(35000) — prompt grew past limit	Fix the threshold or reduce the prompt; do not just document and ignore
Genuine pre-existing	Failure exists on main unrelated to any recent change	See the quarantine ledgers (scripts/ci/quarantined-tests*.txt)	Document in PR body; do not fix unless scoped
New regression	Failure introduced by your changes	Tests for prompt text you removed without updating tests	Fix before pushing

Stale assertions and soft regression indicators are actionable — they signal drift between tests and code. Genuine pre-existing failures are not your responsibility to fix in this PR, but they must be documented.

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Reading CI Failure Logs

When a CI job fails, the GitHub Actions log shows the exact file:line of the failure. Do not guess — read the log.

# Get the failing job URL from the PR
gh pr view <number> --json statusCheckRollup --jq '.statusCheckRollup[] | select(.conclusion=="FAILURE") | .detailsUrl'

# Fetch and search the log (if gh CLI available)
gh run view --log <run-id> | grep -E "FAIL|error" | head -20

Or open the detailsUrl directly in a browser / via WebFetch and search for:

• (fail) — Bun test failure marker
• error: — parse or runtime error
• at <anonymous> — stack frame pointing to the test file and line

Once you have tests/unit/agents/some-file.test.ts:354, reproduce locally:

bun --smol test tests/unit/agents/some-file.test.ts --timeout 30000

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Quick Reference: Common Failures and Causes

Symptom	Likely cause	Fix
scope_exceeded returned from test_runner	Fan-out exceeded 50 test files during graph/impact resolution	Switch to per-file shell loop; reduce changed-files scope
Session killed during test_runner	Pre-fix: unbounded fan-out on multiple files	Now returns scope_exceeded instead — no more session kills
mock.module breaks unrelated tests	Missing spread of real module exports	Add ...realModule spread
Windows tests fail with EBUSY	mock.restore() called while child process holds lock	Add test.skipIf(process.platform === 'win32')
Test output truncated, ID unreadable	Bash tool buffer exceeded	Pipe to Out-File/tee explicitly
for f in ...; do parse error	Bash syntax in PowerShell	Use `Get-ChildItem
Select-String -Last N error	Invalid PowerShell parameter	Use Select-Object -Last N
Token budget test failure	Prompt grew past hardcoded threshold	Treat as soft regression; update threshold
CONSTRAINT assertion fails after refactor	Test checks for removed format template	Update assertion to match current prompt
package-check CI failure	package-check validates the npm tarball (npm pack + tarball contents) — a source/build/package-manifest problem, not generated-file drift	dist/ is generated and NOT committed — do not stage it; run bun run build locally only when you need the bundle. There is no longer a committed-dist drift check.

Tree-sitter / WASM test timeouts

Tests that exercise tree-sitter (any test calling extractFileSymbols or loading a web-tree-sitter grammar) may take several seconds on first WASM module load. Depending on the code path, tree-sitter is reached via the dynamic symbol-graph import or the externalized runtime import; either way, the first Parser.init / grammar load in a process is slow.

• Use --timeout 60000 (not 30000) for test files that load tree-sitter grammars.
• If the test_engineer agent gets stuck (no output for extended time), run the test file directly via bash with a longer timeout (--timeout 120000) to determine whether it's a WASM first-load delay or a genuine code failure.
• Classify the timeout before returning the test_engineer to the coder — a WASM-load timeout is infrastructure, not a code bug.
• Each test process loads WASM independently (no cross-process cache), so every file's first grammar load is slow.