1 files changed, 147 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/tests/no-useless-parameters.js b/tools/lint/eslint/eslint-plugin-mozilla/tests/no-useless-parameters.js
new file mode 100644
index 0000000000..0c9b12f6eb
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/tests/no-useless-parameters.js
@@ -0,0 +1,147 @@
+/* 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-parameters");
+var RuleTester = require("eslint").RuleTester;
+
+const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 6 } });
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+function callError(message) {
+  return [{ message, type: "CallExpression" }];
+}
+
+ruleTester.run("no-useless-parameters", rule, {
+  valid: [
+    "Services.prefs.clearUserPref('browser.search.custom');",
+    "Services.removeObserver('notification name', {});",
+    "Services.io.newURI('http://example.com');",
+    "Services.io.newURI('http://example.com', 'utf8');",
+    "elt.addEventListener('click', handler);",
+    "elt.addEventListener('click', handler, true);",
+    "elt.addEventListener('click', handler, {once: true});",
+    "elt.removeEventListener('click', handler);",
+    "elt.removeEventListener('click', handler, true);",
+    "Services.obs.addObserver(this, 'topic', true);",
+    "Services.obs.addObserver(this, 'topic');",
+    "Services.prefs.addObserver('branch', this, true);",
+    "Services.prefs.addObserver('branch', this);",
+    "array.appendElement(elt);",
+    "Services.obs.notifyObservers(obj, 'topic', 'data');",
+    "Services.obs.notifyObservers(obj, 'topic');",
+    "window.getComputedStyle(elt);",
+    "window.getComputedStyle(elt, ':before');",
+  ],
+  invalid: [
+    {
+      code: "Services.prefs.clearUserPref('browser.search.custom', false);",
+      output: "Services.prefs.clearUserPref('browser.search.custom');",
+      errors: callError("clearUserPref takes only 1 parameter."),
+    },
+    {
+      code: "Services.prefs.clearUserPref('browser.search.custom',\n   false);",
+      output: "Services.prefs.clearUserPref('browser.search.custom');",
+      errors: callError("clearUserPref takes only 1 parameter."),
+    },
+    {
+      code: "Services.removeObserver('notification name', {}, false);",
+      output: "Services.removeObserver('notification name', {});",
+      errors: callError("removeObserver only takes 2 parameters."),
+    },
+    {
+      code: "Services.removeObserver('notification name', {}, true);",
+      output: "Services.removeObserver('notification name', {});",
+      errors: callError("removeObserver only takes 2 parameters."),
+    },
+    {
+      code: "Services.io.newURI('http://example.com', null, null);",
+      output: "Services.io.newURI('http://example.com');",
+      errors: callError("newURI's last parameters are optional."),
+    },
+    {
+      code: "Services.io.newURI('http://example.com', 'utf8', null);",
+      output: "Services.io.newURI('http://example.com', 'utf8');",
+      errors: callError("newURI's last parameters are optional."),
+    },
+    {
+      code: "Services.io.newURI('http://example.com', null);",
+      output: "Services.io.newURI('http://example.com');",
+      errors: callError("newURI's last parameters are optional."),
+    },
+    {
+      code: "Services.io.newURI('http://example.com', '', '');",
+      output: "Services.io.newURI('http://example.com');",
+      errors: callError("newURI's last parameters are optional."),
+    },
+    {
+      code: "Services.io.newURI('http://example.com', '');",
+      output: "Services.io.newURI('http://example.com');",
+      errors: callError("newURI's last parameters are optional."),
+    },
+    {
+      code: "elt.addEventListener('click', handler, false);",
+      output: "elt.addEventListener('click', handler);",
+      errors: callError(
+        "addEventListener's third parameter can be omitted when it's false."
+      ),
+    },
+    {
+      code: "elt.removeEventListener('click', handler, false);",
+      output: "elt.removeEventListener('click', handler);",
+      errors: callError(
+        "removeEventListener's third parameter can be omitted when it's" +
+          " false."
+      ),
+    },
+    {
+      code: "Services.obs.addObserver(this, 'topic', false);",
+      output: "Services.obs.addObserver(this, 'topic');",
+      errors: callError(
+        "addObserver's third parameter can be omitted when it's false."
+      ),
+    },
+    {
+      code: "Services.prefs.addObserver('branch', this, false);",
+      output: "Services.prefs.addObserver('branch', this);",
+      errors: callError(
+        "addObserver's third parameter can be omitted when it's false."
+      ),
+    },
+    {
+      code: "array.appendElement(elt, false);",
+      output: "array.appendElement(elt);",
+      errors: callError(
+        "appendElement's second parameter can be omitted when it's false."
+      ),
+    },
+    {
+      code: "Services.obs.notifyObservers(obj, 'topic', null);",
+      output: "Services.obs.notifyObservers(obj, 'topic');",
+      errors: callError("notifyObservers's third parameter can be omitted."),
+    },
+    {
+      code: "Services.obs.notifyObservers(obj, 'topic', '');",
+      output: "Services.obs.notifyObservers(obj, 'topic');",
+      errors: callError("notifyObservers's third parameter can be omitted."),
+    },
+    {
+      code: "window.getComputedStyle(elt, null);",
+      output: "window.getComputedStyle(elt);",
+      errors: callError("getComputedStyle's second parameter can be omitted."),
+    },
+    {
+      code: "window.getComputedStyle(elt, '');",
+      output: "window.getComputedStyle(elt);",
+      errors: callError("getComputedStyle's second parameter can be omitted."),
+    },
+  ],
+});