Bug 1229588: Add a taskcluster test for eslint. r=dustin

Adds a new lint docker image for linting tools and adds an eslint-gecko task
that uses it to run eslint over the tree.

testing/docker/lint/Dockerfile

@@ -0,0 +1,24 @@
+FROM          node:4.2
+MAINTAINER    Dave Townsend <dtownsend@oxymoronical.com>
+
+RUN useradd -d /home/worker -s /bin/bash -m worker
+WORKDIR /home/worker
+
+# install necessary npm packages
+RUN           npm install -g taskcluster-vcs@2.3.12
+RUN           npm install -g eslint@1.10.3
+RUN           npm install -g eslint-plugin-html@1.1.0
+RUN           npm install -g eslint-plugin-react@3.13.1
+
+# Set variable normally configured at login, by the shells parent process, these
+# are taken from GNU su manual
+ENV           HOME          /home/worker
+ENV           SHELL         /bin/bash
+ENV           USER          worker
+ENV           LOGNAME       worker
+ENV           HOSTNAME      taskcluster-worker
+ENV           LANG          en_US.UTF-8
+ENV           LC_ALL        en_US.UTF-8
+
+# Set a default command useful for debugging
+CMD ["/bin/bash", "--login"]

testing/taskcluster/tasks/branches/base_job_flags.yml

@@ -105,6 +105,7 @@ flags:
     - linux64-st-an
     - macosx64
     - macosx64-st-an
+    - eslint-gecko
 
   tests:
     - cppunit

testing/taskcluster/tasks/branches/base_jobs.yml

@@ -176,6 +176,12 @@ builds:
     types:
       opt:
         task: tasks/builds/android_api_11_b2gdroid.yml
+  eslint-gecko:
+    platforms:
+      - lint
+    types:
+      opt:
+        task: tasks/tests/eslint-gecko.yml
 
 tests:
   cppunit:

testing/taskcluster/tasks/lint.yml

@@ -0,0 +1,40 @@
+# This is the "base" task which contains the common values all linting tests must
+# provide.
+---
+taskId: {{build_slugid}}
+
+task:
+  created: '{{now}}'
+  deadline: '{{#from_now}}24 hours{{/from_now}}'
+  metadata:
+    source: http://todo.com/soon
+    owner: mozilla-taskcluster-maintenance@mozilla.com
+
+  tags:
+    createdForUser: {{owner}}
+
+  workerType: b2gtest
+  provisionerId: aws-provisioner-v1
+  schedulerId: task-graph-scheduler
+
+  routes:
+    - 'index.gecko.v1.{{project}}.revision.linux.{{head_rev}}.{{build_name}}.{{build_type}}'
+    - 'index.gecko.v1.{{project}}.latest.linux.{{build_name}}.{{build_type}}'
+  scopes:
+    # Nearly all of our build tasks use tc-vcs so just include the scope across
+    # the board.
+    - 'docker-worker:cache:tc-vcs'
+
+  payload:
+    # Thirty minutes should be enough for lint checks
+    maxRunTime: 1800
+
+    cache:
+      tc-vcs: '/home/worker/.tc-vcs'
+
+  extra:
+    build_product: '{{build_product}}'
+    build_name: '{{build_name}}'
+    build_type: '{{build_type}}'
+    index:
+      rank: {{pushlog_id}}

testing/taskcluster/tasks/tests/eslint-gecko.yml

@@ -0,0 +1,35 @@
+---
+$inherits:
+    from: 'tasks/lint.yml'
+
+task:
+  metadata:
+    name: '[TC] - ESLint'
+    description: 'ESLint test'
+
+  payload:
+    image:
+      type: 'task-image'
+      path: 'public/image.tar'
+      taskId: '{{#task_id_for_image}}lint{{/task_id_for_image}}'
+
+    command:
+      - bash
+      - -cx
+      - >
+          tc-vcs checkout ./gecko {{base_repository}} {{head_repository}} {{head_rev}} {{head_ref}} &&
+          cd gecko &&
+          npm link testing/eslint-plugin-mozilla &&
+          eslint --plugin html --ext [.js,.jsm,.jsx,.xml,.html] -f tools/lint/eslint-formatter .
+  extra:
+    locations:
+        build: null
+        tests: null
+    treeherder:
+        machine:
+            platform: lint
+        groupSymbol: tc
+        symbol: ES
+    treeherderEnv:
+        - production
+        - staging

tools/lint/eslint-formatter.js

@@ -0,0 +1,23 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+const path = require("path")
+
+module.exports = function(results) {
+  for (let file of results) {
+    let filePath = path.relative(".", file.filePath);
+    for (let message of file.messages) {
+      let status = message.message;
+
+      if ("ruleId" in message) {
+        status = `${status} (${message.ruleId})`;
+      }
+
+      let severity = message.severity == 1 ? "TEST-UNEXPECTED-WARNING"
+                                           : "TEST-UNEXPECTED-ERROR";
+      console.log(`${severity} | ${filePath}:${message.line}:${message.column} | ${status}`);
+    }
+  }
+};