1 files changed, 90 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/tests/reject-globalThis-modification.js b/tools/lint/eslint/eslint-plugin-mozilla/tests/reject-globalThis-modification.js
new file mode 100644
index 0000000000..a0002ff654
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/tests/reject-globalThis-modification.js
@@ -0,0 +1,90 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+var rule = require("../lib/rules/reject-globalThis-modification");
+var RuleTester = require("eslint").RuleTester;
+
+const ruleTester = new RuleTester();
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+function invalidCall(code) {
+  return {
+    code,
+    errors: [
+      {
+        message:
+          "`globalThis` shouldn't be passed to function that can modify it. `globalThis` is the shared global inside the system module, and properties defined on it is visible from all modules.",
+        type: "CallExpression",
+      },
+    ],
+  };
+}
+
+function invalidAssignment(code) {
+  return {
+    code,
+    errors: [
+      {
+        message:
+          "`globalThis` shouldn't be modified. `globalThis` is the shared global inside the system module, and properties defined on it is visible from all modules.",
+        type: "AssignmentExpression",
+      },
+    ],
+  };
+}
+
+ruleTester.run("reject-globalThis-modification", rule, {
+  valid: [
+    `var x = globalThis.Array;`,
+    `Array in globalThis;`,
+    `result.deserialize(globalThis)`,
+  ],
+  invalid: [
+    invalidAssignment(`
+    globalThis.foo = 10;
+`),
+    invalidCall(`
+    Object.defineProperty(globalThis, "foo", { value: 10 });
+`),
+    invalidCall(`
+    Object.defineProperties(globalThis, {
+      foo: { value: 10 },
+    });
+`),
+    invalidCall(`
+    Object.assign(globalThis, { foo: 10 });
+`),
+    invalidCall(`
+    ChromeUtils.defineModuleGetter(
+      globalThis, "AppConstants", "resource://gre/modules/AppConstants.jsm"
+    );
+`),
+    invalidCall(`
+    ChromeUtils.defineESMGetters(globalThis, {
+      AppConstants: "resource://gre/modules/AppConstants.sys.mjs",
+    });
+`),
+    invalidCall(`
+    XPCOMUtils.defineLazyModuleGetter(
+      globalThis, "AppConstants", "resource://gre/modules/AppConstants.jsm"
+    );
+`),
+    invalidCall(`
+    XPCOMUtils.defineLazyModuleGetters(globalThis, {
+      AppConstants: "resource://gre/modules/AppConstants.jsm",
+    });
+`),
+    invalidCall(`
+    someFunction(1, globalThis);
+`),
+  ],
+});