Bug 1905959 - Move jsm rule handling out of eslint-plugin-mozilla to the top-level config. r=frontend-codestyle-reviewers,Gijs

This helps to simplify the combinations in eslint-plugin-mozilla ahead of supporting the ESLint flat config.

Differential Revision: https://phabricator.services.mozilla.com/D215541

.eslintrc.js

@@ -272,6 +272,43 @@ module.exports = {
         "@microsoft/sdl/no-insecure-url": "off",
       },
     },
+    // JSM Handling. This handles the obsolete JSM files whilst we await the
+    // removal of JSM. These reflect some of the rules in recommended.js but
+    // are moved here to simplify reworking the configuration for flat config.
+    {
+      // System mjs files and jsm files are not loaded in the browser scope,
+      // so we turn that off for those. Though we do have our own special
+      // environment for them.
+      env: {
+        browser: false,
+        "mozilla/sysmjs": true,
+      },
+      files: ["**/*.jsm"],
+      rules: {
+        "mozilla/lazy-getter-object-name": "error",
+        "mozilla/mark-exported-symbols-as-used": "error",
+        "mozilla/reject-eager-module-in-lazy-getter": "error",
+        "mozilla/reject-global-this": "error",
+        "mozilla/reject-globalThis-modification": "error",
+        // For all system modules, we expect no properties to need importing,
+        // hence reject everything.
+        "mozilla/reject-importGlobalProperties": ["error", "everything"],
+        "mozilla/reject-mixing-eager-and-lazy": "error",
+        "mozilla/reject-top-level-await": "error",
+        // TODO: Bug 1575506 turn `builtinGlobals` on here.
+        // We can enable builtinGlobals for jsms due to their scopes.
+        "no-redeclare": ["error", { builtinGlobals: false }],
+        // Modules and workers are far easier to check for no-unused-vars on a
+        // global scope, than our content files. Hence we turn that on here.
+        "no-unused-vars": [
+          "error",
+          {
+            argsIgnorePattern: "^_",
+            vars: "all",
+          },
+        ],
+      },
+    },
     ...rollouts,
   ],
 };

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

@@ -45,14 +45,14 @@ module.exports = {
 
   overrides: [
     {
-      // System mjs files and jsm files are not loaded in the browser scope,
+      // System mjs files files are not loaded in the browser scope,
       // so we turn that off for those. Though we do have our own special
       // environment for them.
       env: {
         browser: false,
         "mozilla/sysmjs": true,
       },
-      files: ["**/*.sys.mjs", "**/*.jsm"],
+      files: ["**/*.sys.mjs"],
       rules: {
         "mozilla/lazy-getter-object-name": "error",
         "mozilla/reject-eager-module-in-lazy-getter": "error",
@@ -64,12 +64,12 @@ module.exports = {
         "mozilla/reject-mixing-eager-and-lazy": "error",
         "mozilla/reject-top-level-await": "error",
         // TODO: Bug 1575506 turn `builtinGlobals` on here.
-        // We can enable builtinGlobals for jsms due to their scopes.
+        // We can enable builtinGlobals for mjs files due to their scopes.
         "no-redeclare": ["error", { builtinGlobals: false }],
       },
     },
     {
-      files: ["**/*.mjs", "**/*.jsx", "**/*.jsm", "**/?(*.)worker.?(m)js"],
+      files: ["**/*.mjs", "**/*.jsx", "**/?(*.)worker.?(m)js"],
       rules: {
         // Modules and workers are far easier to check for no-unused-vars on a
         // global scope, than our content files. Hence we turn that on here.
@@ -103,12 +103,6 @@ module.exports = {
         strict: "error",
       },
     },
-    {
-      files: ["**/*.jsm"],
-      rules: {
-        "mozilla/mark-exported-symbols-as-used": "error",
-      },
-    },
     {
       env: {
         browser: false,

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

@@ -1,6 +1,6 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "3.7.4",
+  "version": "3.7.5",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {

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

@@ -1,6 +1,6 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "3.7.4",
+  "version": "3.7.5",
   "description": "A collection of rules that help enforce JavaScript coding standard in the Mozilla project.",
   "keywords": [
     "eslint",