1 files changed, 54 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/consistent-if-bracing.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/consistent-if-bracing.js
new file mode 100644
index 0000000000..0c9c9a342f
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/consistent-if-bracing.js
@@ -0,0 +1,54 @@
+/**
+ * @fileoverview checks if/else if/else bracing is consistent
+ *
+ * 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";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/rules/consistent-if-bracing.html",
+    },
+    messages: {
+      consistentIfBracing: "Bracing of if..else bodies should be consistent.",
+    },
+    schema: [],
+    type: "layout",
+  },
+
+  create(context) {
+    return {
+      IfStatement(node) {
+        if (node.parent.type !== "IfStatement") {
+          let types = new Set();
+          for (
+            let currentNode = node;
+            currentNode;
+            currentNode = currentNode.alternate
+          ) {
+            let type = currentNode.consequent.type;
+            types.add(type == "BlockStatement" ? "Block" : "NotBlock");
+            if (
+              currentNode.alternate &&
+              currentNode.alternate.type !== "IfStatement"
+            ) {
+              type = currentNode.alternate.type;
+              types.add(type == "BlockStatement" ? "Block" : "NotBlock");
+              break;
+            }
+          }
+          if (types.size > 1) {
+            context.report({
+              node,
+              messageId: "consistentIfBracing",
+            });
+          }
+        }
+      },
+    };
+  },
+};