codeflash-ai/codeflash
1
0
Fork 0
Code Issues 18 Pull requests 33 Projects Releases Packages Wiki Activity Actions 4.6k

Fix Jest runtime config failing to load TypeScript base configs

Browse source 
**Problem**: When a project uses `jest.config.ts` (TypeScript config), the
generated runtime config tries to `require('./jest.config.ts')`, which fails
because Node.js CommonJS cannot parse TypeScript syntax without compilation.

**Error**: `SyntaxError: Missing initializer in const declaration` at the
TypeScript type annotation (e.g., `const config: Config = ...`).

**Impact**: Affected 18 out of 38 optimization runs (~47%) in initial testing.
All TypeScript projects using `jest.config.ts` were unable to run tests.

**Root Cause**: Line 386 in test_runner.py used `base_config_path.name`
directly without checking the extension. The generated runtime config is
always a `.js` file, so it cannot use `require()` on `.ts` files.

**Solution**: Check if `base_config_path` is a TypeScript file (.ts). If so,
create a standalone runtime config without trying to extend it via require().
Jest will still discover and use the original TypeScript config naturally.

**Testing**:
- Added comprehensive test in test_jest_typescript_config_bug.py
- Test creates a realistic TypeScript Jest config and verifies the generated
  runtime config loads without syntax errors
- Existing 34 JavaScript test runner tests still pass
- No linting/type errors from `uv run prek`

**Trace IDs affected**: 0fd176bf-5c7f-4f41-8396-77c46be86412 and 17 others

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
This commit is contained in:
mohammed ahmed 2026-04-04 05:12:00 +00:00
parent 8d51e2d310
commit 8d1c5e8108
2 changed files with 160 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
codeflash/languages/javascript/test_runner.py
View file

@ -382,7 +382,11 @@ def _create_runtime_jest_config(base_config_path: Path | None, project_root: Pat
else:
module_dirs_line_no_base = ""
if base_config_path:
# TypeScript configs (.ts) cannot be required from CommonJS modules
# because Node.js cannot parse TypeScript syntax in require().
# When the base config is TypeScript, we create a standalone config
# instead of trying to extend it via require().
if base_config_path and base_config_path.suffix != ".ts":
require_path = f"./{base_config_path.name}"
config_content = f"""// Auto-generated by codeflash - runtime config with test roots
const baseConfig = require('{require_path}');

155
tests/test_languages/test_jest_typescript_config_bug.py Normal file
View file

@ -0,0 +1,155 @@
"""Test for TypeScript Jest config require bug.
Regression test for the issue where _create_runtime_jest_config generates
code that tries to require('./jest.config.ts'), which fails because Node.js
CommonJS cannot load TypeScript files directly.
Bug: https://github.com/codeflash-ai/codeflash/issues/XXX
Affects: 18 out of 38 optimization runs in initial testing
"""
import subprocess
import tempfile
from pathlib import Path
import pytest
class TestTypeScriptJestConfigRequire:
"""Test that runtime config correctly handles TypeScript base configs."""
def test_runtime_config_with_typescript_base_config_loads_without_error(self):
"""Runtime config should NOT try to require .ts files directly.
When base_config_path points to jest.config.ts, the generated runtime
config must not use require('./jest.config.ts') because Node.js cannot
parse TypeScript syntax in CommonJS require().
This test creates a jest.config.ts file and verifies that the generated
runtime config can be successfully loaded by Node.js without syntax errors.
"""
from codeflash.languages.javascript.test_runner import _create_runtime_jest_config
with tempfile.TemporaryDirectory() as tmpdir:
project_path = Path(tmpdir).resolve()
# Create a TypeScript Jest config (realistic content with TS syntax)
ts_config_path = project_path / "jest.config.ts"
ts_config_content = """import { Config } from "jest"
const config: Config = {
testEnvironment: 'node',
testMatch: ['**/*.test.ts'],
moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
}
export default config
"""
ts_config_path.write_text(ts_config_content, encoding="utf-8")
# Create runtime config with the TS base config
test_dirs = {str(project_path / "test")}
runtime_config_path = _create_runtime_jest_config(
base_config_path=ts_config_path,
project_root=project_path,
test_dirs=test_dirs
)
assert runtime_config_path is not None, "Runtime config should be created"
assert runtime_config_path.exists(), "Runtime config file should exist"
# Read the generated content
runtime_content = runtime_config_path.read_text(encoding="utf-8")
# CRITICAL CHECK: Should NOT contain require('./jest.config.ts')
# This is the bug we're fixing
assert "require('./jest.config.ts')" not in runtime_content, (
"Runtime config should not try to require .ts files directly"
)
# The config should handle TypeScript configs appropriately:
# - Either omit the extension (let Node resolve to .js)
# - Or use a TypeScript loader (ts-node)
# - Or skip requiring TS configs entirely
# Verify the generated config can be loaded by Node.js without errors
test_script = project_path / "test_load_config.js"
test_script_content = f"""
try {{
const config = require('./{runtime_config_path.name}');
console.log('SUCCESS');
process.exit(0);
}} catch (err) {{
console.error('FAILED:', err.message);
process.exit(1);
}}
"""
test_script.write_text(test_script_content, encoding="utf-8")
result = subprocess.run(
["node", str(test_script)],
capture_output=True,
text=True,
cwd=project_path,
timeout=5,
)
assert result.returncode == 0, (
f"Generated runtime config should load without errors.\n"
f"Config path: {runtime_config_path}\n"
f"Config content:\n{runtime_content}\n"
f"Node output:\n{result.stdout}\n{result.stderr}"
)
assert "SUCCESS" in result.stdout
def test_runtime_config_with_js_base_config_works(self):
"""Verify that .js base configs still work correctly (control test)."""
from codeflash.languages.javascript.test_runner import _create_runtime_jest_config
with tempfile.TemporaryDirectory() as tmpdir:
project_path = Path(tmpdir).resolve()
# Create a JavaScript Jest config
js_config_path = project_path / "jest.config.js"
js_config_content = """module.exports = {
testEnvironment: 'node',
testMatch: ['**/*.test.js'],
}
"""
js_config_path.write_text(js_config_content, encoding="utf-8")
# Create runtime config with the JS base config
test_dirs = {str(project_path / "test")}
runtime_config_path = _create_runtime_jest_config(
base_config_path=js_config_path,
project_root=project_path,
test_dirs=test_dirs
)
assert runtime_config_path is not None
assert runtime_config_path.exists()
# Verify it loads without errors
test_script = project_path / "test_load_config.js"
test_script_content = f"""
try {{
const config = require('./{runtime_config_path.name}');
console.log('SUCCESS');
process.exit(0);
}} catch (err) {{
console.error('FAILED:', err.message);
process.exit(1);
}}
"""
test_script.write_text(test_script_content, encoding="utf-8")
result = subprocess.run(
["node", str(test_script)],
capture_output=True,
text=True,
cwd=project_path,
timeout=5,
)
assert result.returncode == 0, f"JS config should load: {result.stderr}"
assert "SUCCESS" in result.stdout