Use node api instead of spawning commands to link babel-jest

Author: thymikee

integration-tests/__tests__/transform.test.js

@@ -56,7 +56,7 @@ describe('no babel-jest', () => {
     linkJestPackage('babel-jest', tempDir);
   });
 
-  it('fails with syntax error on flow types', () => {
+  test('fails with syntax error on flow types', () => {
     const {stderr} = runJest(tempDir, ['--no-cache', '--no-watchman']);
     expect(stderr).toMatch(/FAIL.*fails_with_syntax_error/);
     expect(stderr).toMatch('Unexpected token');

integration-tests/utils.js

@@ -43,8 +43,9 @@ const linkJestPackage = (packageName: string, cwd: Path) => {
   const packagesDir = path.resolve(__dirname, '../packages');
   const packagePath = path.resolve(packagesDir, packageName);
   const destination = path.resolve(cwd, 'node_modules/');
-  run(`mkdir -p ${destination}`);
-  return run(`ln -sf ${packagePath} ${destination}`);
+  mkdirp.sync(destination);
+  rimraf.sync(destination);
+  fs.symlinkSync(packagePath, destination, 'dir');
 };
 
 const fileExists = (filePath: Path) => {