Bug 1766228 - Add an ESLint rule to ensure that member property accesses of Services are valid. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D149393

devtools/client/shared/test-helpers/jest-fixtures/Services.js

@@ -12,6 +12,8 @@
 // This fixture is probably doing too much and should be reduced to the minimum
 // needed to pass the tests.
 
+/* eslint-disable mozilla/valid-services */
+
 // Some constants from nsIPrefBranch.idl.
 const PREF_INVALID = 0;
 const PREF_STRING = 32;

docs/code-quality/lint/linters/eslint-plugin-mozilla/valid-services.rst

@@ -0,0 +1,22 @@
+valid-services
+==============
+
+Ensures that accesses of the ``Services`` object are valid.
+
+Examples of incorrect code for this rule:
+-----------------------------------------
+
+Assuming ``foo`` is not defined within Services.
+
+.. code-block:: js
+
+    Services.foo.fn();
+
+Examples of correct code for this rule:
+---------------------------------------
+
+Assuming ``bar`` is defined within Services.
+
+.. code-block:: js
+
+    Services.bar.fn();

tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js

@@ -179,6 +179,7 @@ module.exports = {
     "mozilla/use-ownerGlobal": "error",
     "mozilla/use-returnValue": "error",
     "mozilla/use-services": "error",
+    "mozilla/valid-services": "error",
 
     // Use [] instead of Array()
     "no-array-constructor": "error",

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

@@ -73,6 +73,7 @@ module.exports = {
     "use-isInstance": require("./rules/use-isInstance"),
     "use-returnValue": require("../lib/rules/use-returnValue"),
     "use-services": require("../lib/rules/use-services"),
+    "valid-services": require("../lib/rules/valid-services"),
     "var-only-at-top-level": require("../lib/rules/var-only-at-top-level"),
   },
 };

tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services.js

@@ -0,0 +1,59 @@
+/**
+ * @fileoverview Require use of Services.* rather than getService.
+ *
+ * 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 helpers = require("../helpers");
+
+module.exports = {
+  meta: {
+    docs: {
+      url:
+        "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-services.html",
+    },
+    type: "problem",
+  },
+
+  create(context) {
+    let servicesInterfaceMap = helpers.servicesData;
+    let serviceAliases = new Set([
+      ...Object.values(servicesInterfaceMap),
+      // This is defined only for Android, so most builds won't pick it up.
+      "androidBridge",
+      // These are defined without interfaces and hence are not in the services map.
+      "cpmm",
+      "crashmanager",
+      "mm",
+      "ppmm",
+      // The new xulStore also does not have an interface.
+      "xulStore",
+    ]);
+    return {
+      MemberExpression(node) {
+        if (node.computed || node.object.type !== "Identifier") {
+          return;
+        }
+
+        let alias;
+        if (node.object.name == "Services") {
+          alias = node.property.name;
+        } else if (
+          node.property.name == "Services" &&
+          node.parent.type == "MemberExpression"
+        ) {
+          alias = node.parent.property.name;
+        } else {
+          return;
+        }
+
+        if (!serviceAliases.has(alias)) {
+          context.report(node, `Unknown Services member property ${alias}`);
+        }
+      },
+    };
+  },
+};

tools/lint/eslint/eslint-plugin-mozilla/tests/valid-services.js

@@ -0,0 +1,33 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+var rule = require("../lib/rules/valid-services");
+var RuleTester = require("eslint").RuleTester;
+
+const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 6 } });
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+function invalidCode(code, name) {
+  let message = `Unknown Services member property ${name}`;
+  return { code, errors: [{ message }] };
+}
+
+ruleTester.run("valid-services", rule, {
+  valid: ["Services.crashmanager", "lazy.Services.crashmanager"],
+  invalid: [
+    invalidCode("Services.foo", "foo"),
+    invalidCode("Services.foo()", "foo"),
+    invalidCode("lazy.Services.foo", "foo"),
+    invalidCode("Services.foo.bar()", "foo"),
+    invalidCode("lazy.Services.foo.bar()", "foo"),
+  ],
+});