Adding Node.js version file support (#338)

src/installer.ts

@@ -371,7 +371,7 @@ async function queryDistForMatch(
   }
 
   let versions: string[] = [];
-  let nodeVersions = await module.exports.getVersionsFromDist();
+  let nodeVersions = await getVersionsFromDist();
 
   nodeVersions.forEach((nodeVersion: INodeVersion) => {
     // ensure this version supports your os and platform
@@ -464,3 +464,12 @@ function translateArchToDistUrl(arch: string): string {
       return arch;
   }
 }
+
+export function parseNodeVersionFile(contents: string): string {
+  let nodeVersion = contents.trim();
+
+  if (/^v\d/.test(nodeVersion)) {
+    nodeVersion = nodeVersion.substring(1);
+  }
+  return nodeVersion;
+}

src/main.ts

@@ -1,5 +1,6 @@
 import * as core from '@actions/core';
 import * as installer from './installer';
+import fs from 'fs';
 import * as auth from './authutil';
 import * as path from 'path';
 import {restoreCache} from './cache-restore';
@@ -12,10 +13,7 @@ export async function run() {
     // Version is optional.  If supplied, install / use from the tool cache
     // If not supplied then task is still used to setup proxy, auth, etc...
     //
-    let version = core.getInput('node-version');
-    if (!version) {
-      version = core.getInput('version');
-    }
+    let version = resolveVersionInput();
 
     let arch = core.getInput('architecture');
     const cache = core.getInput('cache');
@@ -63,8 +61,8 @@ export async function run() {
     core.info(
       `##[add-matcher]${path.join(matchersPath, 'eslint-compact.json')}`
     );
-  } catch (error) {
-    core.setFailed(error.message);
+  } catch (err) {
+    core.setFailed(err.message);
   }
 }
 
@@ -74,3 +72,36 @@ function isGhes(): boolean {
   );
   return ghUrl.hostname.toUpperCase() !== 'GITHUB.COM';
 }
+
+function resolveVersionInput(): string {
+  let version = core.getInput('node-version') || core.getInput('version');
+  const versionFileInput = core.getInput('node-version-file');
+
+  if (version && versionFileInput) {
+    core.warning(
+      'Both node-version and node-version-file inputs are specified, only node-version will be used'
+    );
+  }
+
+  if (version) {
+    return version;
+  }
+
+  if (versionFileInput) {
+    const versionFilePath = path.join(
+      process.env.GITHUB_WORKSPACE!,
+      versionFileInput
+    );
+    if (!fs.existsSync(versionFilePath)) {
+      throw new Error(
+        `The specified node version file at: ${versionFilePath} does not exist`
+      );
+    }
+    version = installer.parseNodeVersionFile(
+      fs.readFileSync(versionFilePath, 'utf8')
+    );
+    core.info(`Resolved ${versionFileInput} as ${version}`);
+  }
+
+  return version;
+}