node modules symlink to avoid reinstallation of npm package

codeflash/languages/javascript/mocha_runner.py

@@ -65,14 +65,21 @@ def _ensure_runtime_files(project_root: Path) -> None:
     Installs codeflash package if not already present.
     The package provides all runtime files needed for test instrumentation.
 
+    In monorepos, node_modules may be hoisted to the repo root, so we walk
+    upward from project_root to find an existing codeflash installation.
+
     Args:
         project_root: The project root directory.
 
     """
-    node_modules_pkg = project_root / "node_modules" / "codeflash"
-    if node_modules_pkg.exists():
-        logger.debug("codeflash already installed")
-        return
+    # Walk upward to find codeflash in any ancestor node_modules (monorepo hoisting)
+    current = project_root
+    while current != current.parent:
+        node_modules_pkg = current / "node_modules" / "codeflash"
+        if node_modules_pkg.exists():
+            logger.debug(f"codeflash already installed at {node_modules_pkg}")
+            return
+        current = current.parent
 
     install_cmd = get_package_install_command(project_root, "codeflash", dev=True)
     try:

codeflash/languages/javascript/support.py

@@ -1951,6 +1951,13 @@ def setup_test_config(self, test_cfg: TestConfig, file_path: Path, current_workt
             )
             if original_node_modules.exists() and not worktree_node_modules.exists():
                 worktree_node_modules.symlink_to(original_node_modules)
+            # In monorepos, node_modules lives at the repo root, not the package level.
+            # Symlink the root-level node_modules into the worktree so Vitest/npx can resolve deps.
+            if not worktree_node_modules.exists():
+                worktree_root_node_modules = current_worktree / "node_modules"
+                original_root_node_modules = original_js_root / "node_modules"
+                if original_root_node_modules.exists() and not worktree_root_node_modules.exists():
+                    worktree_root_node_modules.symlink_to(original_root_node_modules)
         verify_js_requirements(test_cfg)
 
     def adjust_test_config_for_discovery(self, test_cfg: TestConfig) -> None:

codeflash/languages/javascript/test_runner.py

@@ -699,14 +699,21 @@ def _ensure_runtime_files(project_root: Path) -> None:
     The package provides all runtime files needed for test instrumentation.
     Uses the project's detected package manager (npm, pnpm, yarn, or bun).
 
+    In monorepos, node_modules may be hoisted to the repo root, so we walk
+    upward from project_root to find an existing codeflash installation.
+
     Args:
         project_root: The project root directory.
 
     """
-    node_modules_pkg = project_root / "node_modules" / "codeflash"
-    if node_modules_pkg.exists():
-        logger.debug("codeflash already installed")
-        return
+    # Walk upward to find codeflash in any ancestor node_modules (monorepo hoisting)
+    current = project_root
+    while current != current.parent:
+        node_modules_pkg = current / "node_modules" / "codeflash"
+        if node_modules_pkg.exists():
+            logger.debug(f"codeflash already installed at {node_modules_pkg}")
+            return
+        current = current.parent
 
     install_cmd = get_package_install_command(project_root, "codeflash", dev=True)
     try:

codeflash/languages/javascript/vitest_runner.py

@@ -6,6 +6,7 @@
 
 from __future__ import annotations
 
+import os
 import subprocess
 import time
 from pathlib import Path
@@ -95,14 +96,21 @@ def _ensure_runtime_files(project_root: Path) -> None:
     The package provides all runtime files needed for test instrumentation.
     Uses the project's detected package manager (npm, pnpm, yarn, or bun).
 
+    In monorepos, node_modules may be hoisted to the repo root, so we walk
+    upward from project_root to find an existing codeflash installation.
+
     Args:
         project_root: The project root directory.
 
     """
-    node_modules_pkg = project_root / "node_modules" / "codeflash"
-    if node_modules_pkg.exists():
-        logger.debug("codeflash already installed")
-        return
+    # Walk upward to find codeflash in any ancestor node_modules (monorepo hoisting)
+    current = project_root
+    while current != current.parent:
+        node_modules_pkg = current / "node_modules" / "codeflash"
+        if node_modules_pkg.exists():
+            logger.debug(f"codeflash already installed at {node_modules_pkg}")
+            return
+        current = current.parent
 
     install_cmd = get_package_install_command(project_root, "codeflash", dev=True)
     try:
@@ -295,6 +303,18 @@ def _build_vitest_behavioral_command(
         if codeflash_vitest_config:
             cmd.append(f"--config={codeflash_vitest_config}")
 
+    # In monorepos, test files may be outside the project root (e.g., tests/ at repo root
+    # while project_root is packages/features/). Vitest only discovers files under its root
+    # directory, so we use --dir to widen the scan to the common ancestor.
+    if project_root and test_files:
+        resolved_root = project_root.resolve()
+        test_dirs = {f.resolve().parent for f in test_files}
+        if any(not d.is_relative_to(resolved_root) for d in test_dirs):
+            all_paths = [str(resolved_root)] + [str(d) for d in test_dirs]
+            common_ancestor = Path(os.path.commonpath(all_paths))
+            cmd.append(f"--dir={common_ancestor}")
+            logger.debug(f"Test files outside project root, using --dir={common_ancestor}")
+
     if output_file:
         # Use dot notation for junit reporter output file when multiple reporters are used
         # Format: --outputFile.junit=/path/to/file.xml
@@ -343,6 +363,16 @@ def _build_vitest_benchmarking_command(
         if codeflash_vitest_config:
             cmd.append(f"--config={codeflash_vitest_config}")
 
+    # In monorepos, test files may be outside the project root. Widen the scan directory.
+    if project_root and test_files:
+        resolved_root = project_root.resolve()
+        test_dirs = {f.resolve().parent for f in test_files}
+        if any(not d.is_relative_to(resolved_root) for d in test_dirs):
+            all_paths = [str(resolved_root)] + [str(d) for d in test_dirs]
+            common_ancestor = Path(os.path.commonpath(all_paths))
+            cmd.append(f"--dir={common_ancestor}")
+            logger.debug(f"Test files outside project root, using --dir={common_ancestor}")
+
     if output_file:
         # Use dot notation for junit reporter output file when multiple reporters are used
         cmd.append(f"--outputFile.junit={output_file}")