support icu messageformat for translations

build/intl-linter/utils/rule.ts

@@ -0,0 +1,33 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { MessageFormatElement } from '@formatjs/icu-messageformat-parser';
+import { Location } from '@formatjs/icu-messageformat-parser';
+import type { Visitor } from './traverse';
+import { traverse } from './traverse';
+
+export type Element = MessageFormatElement;
+export { Location };
+
+export type Context = {
+  messageId: string;
+  report(message: string, location: Location | void): void;
+};
+
+export type RuleFactory = {
+  (context: Context): Visitor;
+};
+
+export type Rule = {
+  id: string;
+  run(elements: Array<MessageFormatElement>, context: Context): void;
+};
+
+export function rule(id: string, ruleFactory: RuleFactory): Rule {
+  return {
+    id,
+    run(elements, context) {
+      traverse(elements, ruleFactory(context));
+    },
+  };
+}