1 files changed, 81 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-multiple-getters-calls.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-multiple-getters-calls.js
new file mode 100644
index 0000000000..56d09d3963
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-multiple-getters-calls.js
@@ -0,0 +1,81 @@
+/**
+ * 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";
+
+const helpers = require("../helpers");
+
+function findStatement(node) {
+  while (node && node.type !== "ExpressionStatement") {
+    node = node.parent;
+  }
+
+  return node;
+}
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url:
+        "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-multiple-getters-calls.html",
+    },
+    messages: {
+      rejectMultipleCalls:
+        "ChromeUtils.defineESModuleGetters is already called for {{target}} in the same context. Please merge those calls",
+    },
+    type: "suggestion",
+  },
+
+  create(context) {
+    const parentToTargets = new Map();
+
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type === "MemberExpression" &&
+          isIdentifier(callee.object, "ChromeUtils") &&
+          isIdentifier(callee.property, "defineESModuleGetters")
+        ) {
+          const stmt = findStatement(node);
+          if (!stmt) {
+            return;
+          }
+
+          let target;
+          try {
+            target = helpers.getASTSource(node.arguments[0]);
+          } catch (e) {
+            return;
+          }
+
+          const parent = stmt.parent;
+          let targets;
+          if (parentToTargets.has(parent)) {
+            targets = parentToTargets.get(parent);
+          } else {
+            targets = new Set();
+            parentToTargets.set(parent, targets);
+          }
+
+          if (targets.has(target)) {
+            context.report({
+              node,
+              messageId: "rejectMultipleCalls",
+              data: { target },
+            });
+          }
+
+          targets.add(target);
+        }
+      },
+    };
+  },
+};