fix: add --prefix to npm install to target correct project directory (#88)

Author: nitinkumar-saucelabs

src/utils.ts

@@ -68,10 +68,15 @@ export async function setUpNpmConfig(
 export async function installNpmDependencies(
   nodeCtx: NodeContext,
   packageList: { [key: string]: string },
+  projectPath?: string,
 ) {
   const packages = Object.entries(packageList).map(([k, v]) => `${k}@${v}`);
   console.log(`\nInstalling packages: ${packages.join(' ')}`);
-  await npm.install(nodeCtx, packages);
+  if (projectPath) {
+    await npm.install(nodeCtx, ['--prefix', projectPath, ...packages]);
+  } else {
+    await npm.install(nodeCtx, packages);
+  }
 }
 
 export async function rebuildNpmDependencies(
@@ -218,8 +223,9 @@ export async function prepareNpmEnv(
   }
 
   // install npm packages
+  const projectPath = path.dirname(runCfg.path);
   startTime = new Date().getTime();
-  await installNpmDependencies(nodeCtx, fixedPackageList);
+  await installNpmDependencies(nodeCtx, fixedPackageList, projectPath);
   endTime = new Date().getTime();
 
   if (runCfg.npm?.usePackageLock !== true) {

tests/unit/src/__snapshots__/utils.spec.ts.snap

@@ -72,6 +72,21 @@ exports[`utils .prepareNpmEnv should call npm install 1`] = `
 ]
 `;
 
+exports[`utils .prepareNpmEnv should call npm install with --prefix when projectPath is provided 1`] = `
+[
+  {
+    "nodePath": "node-bin",
+    "npmPath": "npm-bin",
+    "useGlobals": false,
+  },
+  [
+    "--prefix",
+    "/fake/project",
+    "mypackage@1.2.3",
+  ],
+]
+`;
+
 exports[`utils .prepareNpmEnv should set right registry for npm 1`] = `
 [
   {

tests/unit/src/utils.spec.ts

@@ -152,6 +152,17 @@ describe('utils', function () {
         installSpyOn.mock.calls[installSpyOn.mock.calls.length - 1],
       ).toMatchSnapshot();
     });
+    it('should call npm install with --prefix when projectPath is provided', async function () {
+      const installSpyOn = jest.spyOn(npm, 'install');
+      await installNpmDependencies(
+        nodeCtx,
+        { mypackage: '1.2.3' },
+        '/fake/project',
+      );
+      expect(
+        installSpyOn.mock.calls[installSpyOn.mock.calls.length - 1],
+      ).toMatchSnapshot();
+    });
     it('should use env var for registry', async function () {
       process.env.SAUCE_NPM_CACHE = 'npmland.io';
       const loadSpyOn = jest.spyOn(npm, 'configure');