Extract shared test infrastructure: deduplicate mock providers and setup boilerplate

[codesoda]

Summary

Three patterns of test duplication across the codebase: identical test_artifact_dir() helpers in 2 files plus 10 inline copies, near-identical mock AgentSession implementations in 2 files, and 30+ executor tests repeating the same 3-line setup block.

Severity: S2 (Medium) | Confidence: 0.95 | Blast radius: Low (test-only)

Technical Details

1. test_artifact_dir() — 12 copies across 3 files

Identical private helpers:

• src/executor.rs:1036 — fn test_artifact_dir() -> (TempDir, ArtifactDir)
• src/report.rs:315 — fn test_artifact_dir() -> (TempDir, ArtifactDir)

Inline copies (no helper, pattern repeated directly):

• src/command.rs — 10 instances at lines 654-657, 676-679, 697-700, 720-723, 738-741, 756-759, 784-787, 817-820, 838-841, 858-861:

  let tmp = tempfile::tempdir().unwrap();
  let run_id = RunId("test-run".to_string());
  let artifact_dir = ArtifactDir::from_run_id(tmp.path(), &run_id);
  artifact_dir.create_all().unwrap();

2. Mock AgentSession — 2 near-identical implementations

• src/executor.rs:947-1001 — MockSession with responses: Vec<...>, call_count: usize
• tests/pipeline_integration.rs:21-97 — MockProvider with identical struct layout and logic

Both implement AgentSession with the same stub methods for initialize, start, send_bootstrap, and close. Neither references the other.

3. Per-test setup boilerplate — 30+ copies

Every executor unit test repeats:

let steps = test_steps();
let (run_id, session_id) = test_run_ids();
let (_tmp, artifact_dir) = test_artifact_dir();
// Then: execute_steps(..., None, None, None, Path::new("."), &AtomicBool::new(false))

The 5 trailing None, None, None, Path::new("."), &AtomicBool::new(false) arguments are identical across all 30+ call sites.

Proposed Fix

1. Create src/test_helpers.rs with #[cfg(test)]:

   #[cfg(test)]
   pub mod test_helpers {
       pub fn test_artifact_dir() -> (TempDir, ArtifactDir) { ... }
       pub struct MockSession { ... }
       impl AgentSession for MockSession { ... }
   }

2. Replace all 10 inline copies in command.rs and 2 private helpers with use crate::test_helpers::*
3. Replace MockProvider in pipeline_integration.rs with the shared mock
4. Introduce a TestCtx builder for executor tests:

   struct TestCtx { run_id, session_id, artifact_dir, ... }
   impl TestCtx {
       fn run_steps(&self, session: &mut MockSession, steps: Vec<Step>) -> Result<...> { ... }
   }

Estimated effort: ~6 hours

Related

• Related to F5: test code makes up 1,060 of executor.rs's 1,918 lines
• Part of refactor Bundle 3: Shared Test Infrastructure

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🔍 Found by vibe-code-audit — automated codebase audit skill for Claude Code.