tests: add tests for project root finder util (#1483)

packages/utils/__tests__/find-project-root/package.json

@@ -0,0 +1 @@
+{}

packages/utils/__tests__/find-project-root/project/find-project-root.test.ts

@@ -0,0 +1,24 @@
+// eslint-disable-next-line node/no-unpublished-import
+import { findProjectRoot } from '../../../src/path-utils';
+import { join } from 'path';
+
+beforeAll(() => {
+    // This sets the project root as the root dir, needed since some tests change process cwd.
+    process.chdir(join(__dirname, '../../../../../'));
+});
+
+describe('findProjectRoot function', () => {
+    it('works correctly', () => {
+        /* when no directory is passed, it takes the current process working directory as starting point
+         which contains package.json thus it should be the project root */
+        const projectRoot = findProjectRoot();
+        expect(projectRoot).toEqual(process.cwd());
+    });
+
+    it('works correctly with a non-default dir', () => {
+        /* when passing a custom directory, it's used as the starting point and so it should yield the path
+        nearest package.json from the given directory */
+        const projectRoot = findProjectRoot(__dirname);
+        expect(projectRoot).toEqual(join(__dirname, '..'));
+    });
+});

packages/utils/src/path-utils.ts

@@ -19,12 +19,12 @@ export function isLocalPath(str: string): boolean {
 
 /**
  * Find the root directory path of a project.
- *
+ * @param {String} cwd - Any custom starting point to walk through directories
  * @returns {String} Absolute path of the project root.
  */
 
-export function findProjectRoot(): string {
-    const rootFilePath = findup('package.json');
+export function findProjectRoot(cwd = process.cwd()): string {
+    const rootFilePath = findup('package.json', { cwd });
     const projectRoot = path.dirname(rootFilePath);
     return projectRoot;
 }