Add support for npm

Closes #51

Author: felipecrs

.github/workflows/CI.yml

@@ -73,11 +73,12 @@ jobs:
 
     - run: tests/log-info.sh
     - run: tests/check-version.sh 'volta' 'current'
-    - run: volta install [email protected] [email protected]
+    - run: volta install [email protected] [email protected] [email protected]
     - run: tests/check-version.sh 'node' 'v12.16.1'
+    - run: tests/check-version.sh 'npm' '7.5.2'
     - run: tests/check-version.sh 'yarn' '1.19.1'
 
-  test-specified-node-yarn-overrides-pinned-versions:
+  test-specified-node-npm-yarn-overrides-pinned-versions:
     runs-on: "${{ matrix.os }}-latest"
 
     defaults:
@@ -103,13 +104,15 @@ jobs:
     - uses: ./action
       with:
         node-version: 12.14.0
+        npm-version: 7.5.2
         yarn-version: 1.22.0
 
     - run: tests/log-info.sh
     - run: tests/check-version.sh 'node' 'v12.14.0'
+    - run: tests/check-version.sh 'npm' '7.5.2'
     - run: tests/check-version.sh 'yarn' '1.22.0'
 
-  test-specific-volta-node-yarn:
+  test-specific-volta-node-npm-yarn:
     runs-on: "${{ matrix.os }}-latest"
 
     strategy:
@@ -123,11 +126,13 @@ jobs:
     - run: npm run build
     - uses: ./
       with:
-        volta-version: 0.8.7
+        volta-version: 1.0.1
         node-version: 12.0.0
+        npm-version: 7.5.2
         yarn-version: 1.22.0
 
     - run: tests/log-info.sh
-    - run: tests/check-version.sh 'volta' '0.8.7'
+    - run: tests/check-version.sh 'volta' '1.0.1'
     - run: tests/check-version.sh 'node' 'v12.0.0'
+    - run: tests/check-version.sh 'npm' '7.5.2'
     - run: tests/check-version.sh 'yarn' '1.22.0'

README.md

@@ -54,6 +54,24 @@ steps:
 - run: npm test
 ```
 
+You can also specify the version of npm:
+
+```yaml
+strategy:
+  matrix:
+    node-version: ['^8.12', '10', '12']
+
+steps:
+- uses: actions/checkout@v1
+- uses: volta-cli/action@v1
+  with:
+    node-version: ${{ matrix.node-version }}
+    npm-version: '7'
+
+- run: npm install
+- run: npm test
+```
+
 # License
 
 The scripts and documentation in this project are released under the [MIT License](LICENSE)

action.yml

@@ -8,6 +8,9 @@ inputs:
   node-version:
     description: 'Version Spec of the node version to use.  Examples: 10.6.x, 10.15.1, >=10.15.0'
     default: ''
+  npm-version:
+    description: 'Version Spec of the npm version to use.  Examples: 7.5.x, 7.5.3, >=7.5.3'
+    default: ''
   yarn-version:
     description: 'Version Spec of the yarn version to use.  Examples: 1.6.x, 10.15.1, >=10.15.0'
     default: ''

src/index.ts

@@ -20,6 +20,17 @@ async function run(): Promise<void> {
       }
     }
 
+    const npmVersion = core.getInput('npm-version', { required: false });
+    if (npmVersion !== '') {
+      core.info(`installing NPM ${npmVersion === 'true' ? '' : npmVersion}`);
+      await installer.installNpm(npmVersion);
+
+      // cannot pin `npm` when `node` is not pinned as well
+      if (nodeVersion !== '' && hasPackageJSON) {
+        await installer.pinNpm(npmVersion);
+      }
+    }
+
     const yarnVersion = core.getInput('yarn-version', { required: false });
     if (yarnVersion !== '') {
       core.info(`installing Yarn ${yarnVersion === 'true' ? '' : yarnVersion}`);

src/installer.ts

@@ -168,6 +168,10 @@ export async function installNode(version: string): Promise<void> {
   await execVolta(['install', `node${version === 'true' ? '' : `@${version}`}`]);
 }
 
+export async function installNpm(version: string): Promise<void> {
+  await execVolta(['install', `npm${version === 'true' ? '' : `@${version}`}`]);
+}
+
 export async function installYarn(version: string): Promise<void> {
   await execVolta(['install', `yarn${version === 'true' ? '' : `@${version}`}`]);
 }
@@ -176,6 +180,10 @@ export async function pinNode(version: string): Promise<void> {
   await execVolta(['pin', `node${version === 'true' ? '' : `@${version}`}`]);
 }
 
+export async function pinNpm(version: string): Promise<void> {
+  await execVolta(['pin', `npm${version === 'true' ? '' : `@${version}`}`]);
+}
+
 export async function pinYarn(version: string): Promise<void> {
   await execVolta(['pin', `yarn${version === 'true' ? '' : `@${version}`}`]);
 }