NodeToolV0: allow reading versionSpec from file

Tasks/NodeToolV0/Strings/resources.resjson/en-US/resources.resjson

@@ -4,7 +4,7 @@
   "loc.description": "Finds or downloads and caches the specified version spec of Node.js and adds it to the PATH",
   "loc.instanceNameFormat": "Use Node $(versionSpec)",
   "loc.input.label.versionSpec": "Version Spec",
-  "loc.input.help.versionSpec": "Version Spec of version to get.  Examples: 6.x, 4.x, 6.10.0, >=6.10.0",
+  "loc.input.help.versionSpec": "Version Spec of version to get.  Examples: 6.x, 4.x, 6.10.0, >=6.10.0. Also supports a path to a file.  Examples: src/.nvmrc, .node-version",
   "loc.input.label.checkLatest": "Check for Latest Version",
   "loc.input.help.checkLatest": "Always checks online for the latest available version that satisfies the version spec. This is typically false unless you have a specific scenario to always get latest. This will cause it to incur download costs when potentially not necessary, especially with the hosted build pool.",
   "loc.input.label.force32bit": "Use 32 bit version on x64 agents",

Tasks/NodeToolV0/Tests/L0.ts

@@ -73,4 +73,18 @@ describe('NodeTool Suite', function () {
         }, tr, done);
     });
 
+    it('Reads node version from nvmrc', (done: Mocha.Done) => {
+        this.timeout(5000);
+
+        let tp: string = path.join(__dirname, 'L0ReadsNvmrc.js');
+        let tr: ttm.MockTestRunner = new ttm.MockTestRunner(tp);
+
+        tr.run();
+
+        runValidations(() => {
+            assert(tr.succeeded, 'NodeTool should have succeeded.');
+            assert(tr.stderr.length === 0, 'NodeTool should not have written to stderr');
+        }, tr, done);
+    });
+
 });

Tasks/NodeToolV0/Tests/L0ReadsNvmrc.ts

@@ -0,0 +1,100 @@
+import ma = require('azure-pipelines-task-lib/mock-answer');
+import tmrm = require('azure-pipelines-task-lib/mock-run');
+import os = require('os');
+import path = require('path');
+import semver = require('semver');
+
+let taskPath = path.join(__dirname, '..', 'nodetool.js');
+let tmr: tmrm.TaskMockRunner = new tmrm.TaskMockRunner(taskPath);
+
+tmr.setInput('versionSpec', 'src/.nvmrc');
+
+let a: ma.TaskLibAnswers = <ma.TaskLibAnswers>{
+    "assertAgent": {
+        "2.115.1": true
+    },
+    "checkPath": {
+        ".nvmrc": true,
+    },
+};
+tmr.setAnswers(a);
+
+
+//Create assertAgent and getVariable mocks
+const tl = require('azure-pipelines-task-lib/mock-task');
+const tlClone = Object.assign({}, tl);
+tlClone.getVariable = function (variable: string) {
+    if (variable.toLowerCase() == 'agent.tempdirectory') {
+        return 'temp';
+    }
+    return null;
+};
+tlClone.assertAgent = function (variable: string) {
+    return;
+};
+tmr.registerMock('azure-pipelines-task-lib/mock-task', tlClone);
+
+tmr.registerMock('fs', {
+    readFileSync: function (path, options) {
+        if (path != 'src/.nvmrc') {
+            throw new Error(`reading wrong .nvmrc: '${[path]}'`);
+        }
+
+        return '0.6.21';
+    }
+});
+
+//Create tool-lib mock
+tmr.registerMock('azure-pipelines-tool-lib/tool', {
+    isExplicitVersion: semver.valid,
+    findLocalTool: function (toolName, versionSpec) {
+        if (toolName != 'node') {
+            throw new Error('Searching for wrong tool');
+        }
+        return false;
+    },
+    evaluateVersions: function (versions, versionSpec) {
+        if (versionSpec !== 'v0.6.21') {
+            throw new Error(`Incorrect versionSpec: ${versionSpec}`);
+        }
+        return versionSpec;
+    },
+    cleanVersion: semver.clean,
+    downloadTool(url) {
+        let err = new Error();
+        err['httpStatusCode'] = '404';
+        if (url === `https://nodejs.org/dist/v0.6.21/node-v0.6.21-win-${os.arch()}.7z` ||
+            url === `https://nodejs.org/dist/v0.6.21/node-v0.6.21-${os.platform()}-${os.arch()}.tar.gz`) {
+            throw err;
+        }
+        else if (url === `https://nodejs.org/dist/v0.6.21/win-${os.arch()}/node.exe`) {
+            throw err;
+        }
+        else if (url === `https://nodejs.org/dist/v0.6.21/win-${os.arch()}/node.lib`) {
+            throw err;
+        }
+        else if (url === `https://nodejs.org/dist/v0.6.21/node.exe`) {
+            return 'exe_loc';
+        }
+        else if (url === `https://nodejs.org/dist/v0.6.21/node.lib`) {
+            return 'exe_lib';
+        }
+        else {
+            throw new Error(`Incorrect URL: ${url}`);
+        }
+    },
+    extract7z(downloadPath, extPath, _7zPath) {
+        return 'extPath';
+    },
+    extractTar(downloadPath, extPath, _7zPath) {
+        return 'extPath';
+    },
+    cacheDir(dir, tool, version) {
+        return 'path to tool';
+    },
+    prependPath(toolPath) {
+        return;
+    }
+});
+
+tmr.run();

Tasks/NodeToolV0/nodetool.ts

@@ -4,14 +4,15 @@ import * as restm from 'typed-rest-client/RestClient';
 import * as telemetry from 'azure-pipelines-tasks-utility-common/telemetry';
 import * as os from 'os';
 import * as path from 'path';
+import * as fs from 'fs';
 
 const force32bit: boolean = taskLib.getBoolInput('force32bit', false);
 let osPlat: string = os.platform();
 let osArch: string = getArch();
 
 async function run() {
     try {
-        let versionSpec = taskLib.getInput('versionSpec', true);
+        let versionSpec = getVersionSpec();
         let checkLatest: boolean = taskLib.getBoolInput('checkLatest', false);
         await getNode(versionSpec, checkLatest);
         telemetry.emitTelemetry('TaskHub', 'NodeToolV0', { versionSpec, checkLatest, force32bit });
@@ -21,6 +22,20 @@ async function run() {
     }
 }
 
+function getVersionSpec() {
+    const versionSpecInput = taskLib.getInput('versionSpec', true);
+
+    const cleanVersion = toolLib.cleanVersion(versionSpecInput);
+    if (cleanVersion) {
+        taskLib.debug(`version spec '${cleanVersion}' from '${versionSpecInput}'`);
+        return versionSpecInput;
+    }
+
+    const versionSpec = fs.readFileSync(versionSpecInput, { 'encoding': 'utf' });
+    taskLib.debug(`Got node version spec '${versionSpec}' from file '${versionSpecInput}'`);
+    return versionSpec;
+}
+
 //
 // Node versions interface
 // see https://nodejs.org/dist/index.json

Tasks/NodeToolV0/task.json

@@ -31,7 +31,7 @@
             "label": "Version Spec",
             "defaultValue": "6.x",
             "required": true,
-            "helpMarkDown": "Version Spec of version to get.  Examples: 6.x, 4.x, 6.10.0, >=6.10.0"
+            "helpMarkDown": "Version Spec of version to get.  Examples: 6.x, 4.x, 6.10.0, >=6.10.0. Also supports a path to a file.  Examples: src/.nvmrc, .node-version"
         },
         {
             "name": "checkLatest",