Merge pull request #1808 from codeflash-ai/fix/jest-runtime-config-for-external-tests

fix: use runtime Jest config for test files outside project root

Author: mohammedahmed18

codeflash/languages/javascript/test_runner.py

@@ -339,6 +339,73 @@ def _create_codeflash_jest_config(
         return None
 
 
+def _create_runtime_jest_config(base_config_path: Path | None, project_root: Path, test_dirs: set[str]) -> Path | None:
+    """Create a runtime Jest config that includes test directories in roots and testMatch.
+
+    This is needed because test files generated by codeflash may be placed
+    outside the project root (e.g., in a monorepo where the source file lives
+    in a subpackage but tests are generated at the repo root). Jest requires
+    test files to be within configured ``roots`` and to match ``testMatch``
+    patterns (which typically use ``<rootDir>``). Since ``roots`` set via CLI
+    can be overridden by config, and ``testMatch`` patterns using ``<rootDir>``
+    won't match files outside the project root, we must create a wrapper config.
+
+    Args:
+        base_config_path: Path to the base Jest config to extend, or None.
+        project_root: The project root directory (where package.json lives).
+        test_dirs: Set of absolute directory paths containing test files.
+
+    Returns:
+        Path to the created runtime config file.
+
+    """
+    is_esm = _is_esm_project(project_root)
+    config_ext = ".cjs" if is_esm else ".js"
+
+    if base_config_path:
+        config_dir = base_config_path.parent
+    else:
+        config_dir = project_root
+
+    runtime_config_path = config_dir / f"jest.codeflash.runtime.config{config_ext}"
+
+    test_dirs_js = ", ".join(f"'{d}'" for d in sorted(test_dirs))
+
+    if base_config_path:
+        require_path = f"./{base_config_path.name}"
+        config_content = f"""// Auto-generated by codeflash - runtime config with test roots
+const baseConfig = require('{require_path}');
+module.exports = {{
+  ...baseConfig,
+  roots: [
+    ...(baseConfig.roots || [__dirname]),
+    {test_dirs_js},
+  ],
+  testMatch: ['**/*.test.ts', '**/*.test.js', '**/*.test.tsx', '**/*.test.jsx'],
+}};
+"""
+    else:
+        config_content = f"""// Auto-generated by codeflash - runtime config with test roots
+module.exports = {{
+  roots: ['{project_root}', {test_dirs_js}],
+  testMatch: ['**/*.test.ts', '**/*.test.js', '**/*.test.tsx', '**/*.test.jsx'],
+}};
+"""
+
+    try:
+        runtime_config_path.write_text(config_content, encoding="utf-8")
+        _created_config_files.add(runtime_config_path)
+        logger.debug(f"Created runtime Jest config with test roots: {runtime_config_path}")
+    except Exception as e:
+        logger.warning(f"Failed to create runtime Jest config: {e}")
+        # Fall back to base config
+        if base_config_path:
+            return base_config_path
+        return None
+
+    return runtime_config_path
+
+
 def _get_jest_config_for_project(project_root: Path) -> Path | None:
     """Get the appropriate Jest config for the project.
 
@@ -712,6 +779,17 @@ def run_jest_behavioral_tests(
     # Add Jest config if found - needed for TypeScript transformation
     # Uses codeflash-compatible config if project has bundler moduleResolution
     jest_config = _get_jest_config_for_project(effective_cwd)
+
+    # If test files are outside the project root, create a runtime wrapper config
+    # that adds their directories to Jest's `roots` and overrides `testMatch`.
+    # This is necessary because Jest's testMatch patterns use <rootDir> which
+    # resolves to the config file's directory, excluding external test files.
+    if test_files:
+        resolved_root = effective_cwd.resolve()
+        test_dirs = {str(Path(f).resolve().parent) for f in test_files}
+        if any(not Path(d).is_relative_to(resolved_root) for d in test_dirs):
+            jest_config = _create_runtime_jest_config(jest_config, effective_cwd, test_dirs)
+
     if jest_config:
         jest_cmd.append(f"--config={jest_config}")
 
@@ -723,12 +801,6 @@ def run_jest_behavioral_tests(
         jest_cmd.append("--runTestsByPath")
         resolved_test_files = [str(Path(f).resolve()) for f in test_files]
         jest_cmd.extend(resolved_test_files)
-        # Add --roots to include directories containing test files
-        # This is needed because some projects configure Jest with restricted roots
-        # (e.g., roots: ["<rootDir>/src"]) which excludes the test directory
-        test_dirs = {str(Path(f).resolve().parent) for f in test_files}
-        for test_dir in sorted(test_dirs):
-            jest_cmd.extend(["--roots", test_dir])
 
     if timeout:
         jest_cmd.append(f"--testTimeout={timeout * 1000}")  # Jest uses milliseconds
@@ -962,17 +1034,21 @@ def run_jest_benchmarking_tests(
     # Add Jest config if found - needed for TypeScript transformation
     # Uses codeflash-compatible config if project has bundler moduleResolution
     jest_config = _get_jest_config_for_project(effective_cwd)
+
+    # If test files are outside the project root, create a runtime wrapper config
+    if test_files:
+        resolved_root = effective_cwd.resolve()
+        test_dirs = {str(Path(f).resolve().parent) for f in test_files}
+        if any(not Path(d).is_relative_to(resolved_root) for d in test_dirs):
+            jest_config = _create_runtime_jest_config(jest_config, effective_cwd, test_dirs)
+
     if jest_config:
         jest_cmd.append(f"--config={jest_config}")
 
     if test_files:
         jest_cmd.append("--runTestsByPath")
         resolved_test_files = [str(Path(f).resolve()) for f in test_files]
         jest_cmd.extend(resolved_test_files)
-        # Add --roots to include directories containing test files
-        test_dirs = {str(Path(f).resolve().parent) for f in test_files}
-        for test_dir in sorted(test_dirs):
-            jest_cmd.extend(["--roots", test_dir])
 
     if timeout:
         jest_cmd.append(f"--testTimeout={timeout * 1000}")
@@ -1127,17 +1203,21 @@ def run_jest_line_profile_tests(
     # Add Jest config if found - needed for TypeScript transformation
     # Uses codeflash-compatible config if project has bundler moduleResolution
     jest_config = _get_jest_config_for_project(effective_cwd)
+
+    # If test files are outside the project root, create a runtime wrapper config
+    if test_files:
+        resolved_root = effective_cwd.resolve()
+        test_dirs = {str(Path(f).resolve().parent) for f in test_files}
+        if any(not Path(d).is_relative_to(resolved_root) for d in test_dirs):
+            jest_config = _create_runtime_jest_config(jest_config, effective_cwd, test_dirs)
+
     if jest_config:
         jest_cmd.append(f"--config={jest_config}")
 
     if test_files:
         jest_cmd.append("--runTestsByPath")
         resolved_test_files = [str(Path(f).resolve()) for f in test_files]
         jest_cmd.extend(resolved_test_files)
-        # Add --roots to include directories containing test files
-        test_dirs = {str(Path(f).resolve().parent) for f in test_files}
-        for test_dir in sorted(test_dirs):
-            jest_cmd.extend(["--roots", test_dir])
 
     if timeout:
         jest_cmd.append(f"--testTimeout={timeout * 1000}")