1 files changed, 65 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-arbitrary-setTimeout.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-arbitrary-setTimeout.js
new file mode 100644
index 0000000000..1888aff916
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-arbitrary-setTimeout.js
@@ -0,0 +1,65 @@
+/**
+ * @fileoverview Reject use of non-zero values in setTimeout
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+var testTypes = new Set(["browser", "xpcshell"]);
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-arbitrary-setTimeout.html",
+    },
+    messages: {
+      listenForEvents:
+        "listen for events instead of setTimeout() with arbitrary delay",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    // We don't want to run this on mochitest plain as it already
+    // prevents flaky setTimeout at runtime. This check is built-in
+    // to the rule itself as sometimes other tests can live alongside
+    // plain mochitests and so it can't be configured via eslintrc.
+    if (!testTypes.has(helpers.getTestType(context))) {
+      return {};
+    }
+
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (callee.type === "MemberExpression") {
+          if (
+            callee.property.name !== "setTimeout" ||
+            callee.object.name !== "window" ||
+            node.arguments.length < 2
+          ) {
+            return;
+          }
+        } else if (callee.type === "Identifier") {
+          if (callee.name !== "setTimeout" || node.arguments.length < 2) {
+            return;
+          }
+        } else {
+          return;
+        }
+
+        let timeout = node.arguments[1];
+        if (timeout.type !== "Literal" || timeout.value > 0) {
+          context.report({
+            node,
+            messageId: "listenForEvents",
+          });
+        }
+      },
+    };
+  },
+};