1 files changed, 96 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/tests/no-useless-removeEventListener.js b/tools/lint/eslint/eslint-plugin-mozilla/tests/no-useless-removeEventListener.js
new file mode 100644
index 0000000000..f5fc60158d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/tests/no-useless-removeEventListener.js
@@ -0,0 +1,96 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+var rule = require("../lib/rules/no-useless-removeEventListener");
+var RuleTester = require("eslint").RuleTester;
+
+const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: "latest" } });
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+function invalidCode(code) {
+  return { code, errors: [{ messageId: "useOnce", type: "CallExpression" }] };
+}
+
+ruleTester.run("no-useless-removeEventListener", rule, {
+  valid: [
+    // Listeners that aren't a function are always valid.
+    "elt.addEventListener('click', handler);",
+    "elt.addEventListener('click', handler, true);",
+    "elt.addEventListener('click', handler, {once: true});",
+
+    // Should not fail on empty functions.
+    "elt.addEventListener('click', function() {});",
+
+    // Should not reject when removing a listener for another event.
+    "elt.addEventListener('click', function listener() {" +
+      "  elt.removeEventListener('keypress', listener);" +
+      "});",
+
+    // Should not reject when there's another instruction before
+    // removeEventListener.
+    "elt.addEventListener('click', function listener() {" +
+      "  elt.focus();" +
+      "  elt.removeEventListener('click', listener);" +
+      "});",
+
+    // Should not reject when wantsUntrusted is true.
+    "elt.addEventListener('click', function listener() {" +
+      "  elt.removeEventListener('click', listener);" +
+      "}, false, true);",
+
+    // Should not reject when there's a literal and a variable
+    "elt.addEventListener('click', function listener() {" +
+      "  elt.removeEventListener(eventName, listener);" +
+      "});",
+
+    // Should not reject when there's 2 different variables
+    "elt.addEventListener(event1, function listener() {" +
+      "  elt.removeEventListener(event2, listener);" +
+      "});",
+
+    // Should not fail if this is a different type of event listener function.
+    "myfunc.addEventListener(listener);",
+  ],
+  invalid: [
+    invalidCode(
+      "elt.addEventListener('click', function listener() {" +
+        "  elt.removeEventListener('click', listener);" +
+        "});"
+    ),
+    invalidCode(
+      "elt.addEventListener('click', function listener() {" +
+        "  elt.removeEventListener('click', listener, true);" +
+        "}, true);"
+    ),
+    invalidCode(
+      "elt.addEventListener('click', function listener() {" +
+        "  elt.removeEventListener('click', listener);" +
+        "}, {once: true});"
+    ),
+    invalidCode(
+      "elt.addEventListener('click', function listener() {" +
+        "  /* Comment */" +
+        "  elt.removeEventListener('click', listener);" +
+        "});"
+    ),
+    invalidCode(
+      "elt.addEventListener('click', function() {" +
+        "  elt.removeEventListener('click', arguments.callee);" +
+        "});"
+    ),
+    invalidCode(
+      "elt.addEventListener(eventName, function listener() {" +
+        "  elt.removeEventListener(eventName, listener);" +
+        "});"
+    ),
+  ],
+});