Bug 1330006 - Land and enable self-hosted JS eslint plugin. r=till,mossop

.eslintignore

@@ -24,7 +24,6 @@ hal/**
 image/**
 intl/**
 ipc/**
-js/**
 layout/**
 media/**
 memory/**
@@ -154,6 +153,17 @@ devtools/client/framework/test/code_ugly*
 devtools/server/tests/unit/babel_and_browserify_script_with_source_map.js
 devtools/server/tests/unit/setBreakpoint*
 
+# Exclude everything but self-hosted JS
+js/ductwork/**
+js/examples/**
+js/ipc/**
+js/public/**
+js/xpconnect/**
+js/src/devtools/**
+js/src/octane/**
+js/src/jit-test/**
+js/src/tests/**
+
 # mobile/android/ exclusions
 mobile/android/tests/
 

js/src/builtin/.eslintrc.js

@@ -0,0 +1,22 @@
+"use strict";
+
+module.exports = {
+  "extends": [
+    "../../../toolkit/.eslintrc.js"
+  ],
+
+  "rules": {
+    // We should fix those at some point, but we use this to detect NaNs.
+    "no-self-compare": "off",
+    // Disabling these two make it easier to implement the spec.
+    "spaced-comment": "off",
+    "no-lonely-if": "off",
+    // SpiderMonkey's style doesn't match any of the possible options.
+    "brace-style": "off",
+    // Manually defining all the selfhosted methods is a slog.
+    "no-undef": "off",
+    // Disabled until we can use let/const to fix those erorrs,
+    // and undefined names cause an exception and abort during runtime initialization.
+    "no-redeclare": "off",
+  }
+};

tools/lint/eslint/eslint-plugin-mozilla/lib/index.js

@@ -15,6 +15,7 @@
 module.exports = {
   processors: {
     ".xml": require("../lib/processors/xbl-bindings"),
+    ".js": require("../lib/processors/self-hosted"),
   },
   rules: {
     "avoid-removeChild": require("../lib/rules/avoid-removeChild"),

tools/lint/eslint/eslint-plugin-mozilla/lib/processors/self-hosted.js

@@ -0,0 +1,44 @@
+/**
+ * @fileoverview Remove macros from SpiderMonkey's self-hosted JS.
+ *
+ * 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 selfHostedRegex = /js\/src\/builtin\/.*?\.js$/;
+const macroRegex = /\s*\#(if|ifdef|else|elif|endif|include|define|undef).*/;
+
+module.exports = {
+  preprocess: function(text, filename) {
+    if (!selfHostedRegex.test(filename)) {
+      return [text];
+    }
+
+    let lines = text.split(/\n/);
+    for (let i = 0; i < lines.length; i++) {
+      if (!macroRegex.test(lines[i])) {
+        // No macro here, nothing to do.
+        continue;
+      }
+
+      for (; i < lines.length; i++) {
+        lines[i] = "// " + lines[i];
+
+        // If the line ends with a backslash (\), the next line
+        // is also part of part of the macro.
+        if (!lines[i].endsWith("\\")) {
+          break;
+        }
+      }
+    }
+
+    return [lines.join("\n")];
+  },
+
+  postprocess: function(messages, filename) {
+    return Array.prototype.concat.apply([], messages);
+  }
+}

tools/lint/eslint/eslint-plugin-mozilla/package.json

@@ -1,6 +1,6 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "0.2.18",
+  "version": "0.2.19",
   "description": "A collection of rules that help enforce JavaScript coding standard in the Mozilla project.",
   "keywords": [
     "eslint",