download from node-versions and fallback to node dist (#147)

* download LTS versions from releases

* support upcoiming ghes 

Co-authored-by: eric sciple <ericsciple@users.noreply.github.com>

src/main.ts

@@ -0,0 +1,50 @@
+import * as core from '@actions/core';
+import * as installer from './installer';
+import * as auth from './authutil';
+import * as path from 'path';
+import {URL} from 'url';
+
+export async function run() {
+  try {
+    //
+    // 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');
+    }
+
+    console.log(`version: ${version}`);
+    if (version) {
+      let token = core.getInput('token');
+      let auth = !token || isGhes() ? undefined : `token ${token}`;
+      let stable = (core.getInput('stable') || 'true').toUpperCase() === 'TRUE';
+      await installer.getNode(version, stable, auth);
+    }
+
+    const registryUrl: string = core.getInput('registry-url');
+    const alwaysAuth: string = core.getInput('always-auth');
+    if (registryUrl) {
+      auth.configAuthentication(registryUrl, alwaysAuth);
+    }
+
+    const matchersPath = path.join(__dirname, '..', '.github');
+    console.log(`##[add-matcher]${path.join(matchersPath, 'tsc.json')}`);
+    console.log(
+      `##[add-matcher]${path.join(matchersPath, 'eslint-stylish.json')}`
+    );
+    console.log(
+      `##[add-matcher]${path.join(matchersPath, 'eslint-compact.json')}`
+    );
+  } catch (error) {
+    core.setFailed(error.message);
+  }
+}
+
+function isGhes(): boolean {
+  const ghUrl = new URL(
+    process.env['GITHUB_SERVER_URL'] || 'https://github.com'
+  );
+  return ghUrl.hostname.toUpperCase() !== 'GITHUB.COM';
+}