Bug 1596918: Part 2 - Add ESLint support for SpecialPowers.spawn globals. r=Standard8

This patch updates the existing ContentTask.spawn rule to do similar things
for SpecialPowers.spawn calls, only with a slightly different set of globals.

Differential Revision: https://phabricator.services.mozilla.com/D53739

--HG--
extra : moz-landing-system : lando

testing/specialpowers/content/SpecialPowersSandbox.jsm

@@ -18,6 +18,9 @@ ChromeUtils.defineModuleGetter(
   "resource://testing-common/Assert.jsm"
 );
 
+// Note: When updating the set of globals exposed to sandboxes by
+// default, please also update the ESLint plugin rule defined in
+// import-content-task-globals.js.
 const SANDBOX_GLOBALS = [
   "Blob",
   "ChromeUtils",
@@ -25,6 +28,10 @@ const SANDBOX_GLOBALS = [
   "TextEncoder",
   "URL",
 ];
+const EXTRA_IMPORTS = {
+  EventUtils: "resource://specialpowers/SpecialPowersEventUtils.jsm",
+  Services: "resource://gre/modules/Services.jsm",
+};
 
 let expectFail = false;
 function expectingFail(fn) {
@@ -62,14 +69,16 @@ class SpecialPowersSandbox {
     }
 
     let imports = {
-      EventUtils: "resource://specialpowers/SpecialPowersEventUtils.jsm",
-      Services: "resource://gre/modules/Services.jsm",
+      ...EXTRA_IMPORTS,
       ...opts.imports,
     };
     for (let [symbol, url] of Object.entries(imports)) {
       ChromeUtils.defineModuleGetter(this.sandbox, symbol, url);
     }
 
+    // Note: When updating the set of globals exposed to sandboxes by
+    // default, please also update the ESLint plugin rule defined in
+    // import-content-task-globals.js.
     Object.assign(this.sandbox, {
       BrowsingContext,
       InspectorUtils,

tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-content-task-globals.js

@@ -36,5 +36,38 @@ module.exports = function(context) {
         );
       }
     },
+    "CallExpression[callee.object.name='SpecialPowers'][callee.property.name='spawn']": function(
+      node
+    ) {
+      // The global environment of SpecialPowers.spawn tasks is
+      // controlled by the Sandbox environment created by
+      // SpecialPowersSandbox.jsm. This list should be kept in sync with
+      // that module.
+      let globals = [
+        "Assert",
+        "Blob",
+        "BrowsingContext",
+        "ChromeUtils",
+        "ContentTaskUtils",
+        "EventUtils",
+        "Services",
+        "SpecialPowers",
+        "TextDecoder",
+        "TextEncoder",
+        "URL",
+        "assert",
+        "content",
+        "docShell",
+        "info",
+        "is",
+        "isnot",
+        "ok",
+        "todo",
+        "todo_is",
+      ];
+      for (let global of globals) {
+        helpers.addVarToScope(global, context.getScope(), false);
+      }
+    },
   };
 };