feat: Extract useTranslations/getTranslations usages in SWC plugin

packages/next-intl/src/extractor/catalog/CatalogManager.tsx

@@ -11,7 +11,7 @@ import type {
   ExtractorConfig,
   ExtractorMessage,
   Locale,
-  SourceMessage
+  SourceExtractedMessage
 } from '../types.js';
 import {
   compareReferences,
@@ -43,17 +43,17 @@ export default class CatalogManager implements Disposable {
    */
   private sourceMessagesByFile: Map<
     /* File path */ string,
-    Map</* ID */ string, Array<SourceMessage>>
+    Map</* ID */ string, Array<SourceExtractedMessage>>
   > = new Map();
 
   /**
    * Reverse index for rebuilding aggregated messages without scanning all files.
-   * Contains the same `SourceMessage` arrays as `sourceMessagesByFile` and is
+   * Contains the same `SourceExtractedMessage` arrays as `sourceMessagesByFile` and is
    * kept in sync with it.
    */
   private sourceMessagesById: Map<
     /* ID */ string,
-    Map</* File path */ string, Array<SourceMessage>>
+    Map</* File path */ string, Array<SourceExtractedMessage>>
   > = new Map();
 
   /**
@@ -308,8 +308,8 @@ export default class CatalogManager implements Disposable {
 
   private async extractFile(
     absoluteFilePath: string
-  ): Promise<Array<SourceMessage> | undefined> {
-    let messages: Array<SourceMessage> = [];
+  ): Promise<Array<SourceExtractedMessage> | undefined> {
+    let messages: Array<SourceExtractedMessage> = [];
     try {
       const content = await fs.readFile(absoluteFilePath, 'utf8');
       let extraction: Awaited<ReturnType<typeof this.extractor.extract>>;
@@ -330,7 +330,7 @@ export default class CatalogManager implements Disposable {
 
   private applyFileMessages(
     absoluteFilePath: string,
-    messages: Array<SourceMessage>
+    messages: Array<SourceExtractedMessage>
   ): boolean {
     const prevFileMessages = this.sourceMessagesByFile.get(absoluteFilePath);
     const nextFileMessages = this.groupSourceMessagesById(messages);
@@ -378,9 +378,9 @@ export default class CatalogManager implements Disposable {
   }
 
   private groupSourceMessagesById(
-    messages: Array<SourceMessage>
-  ): Map<string, Array<SourceMessage>> {
-    const result = new Map<string, Array<SourceMessage>>();
+    messages: Array<SourceExtractedMessage>
+  ): Map<string, Array<SourceExtractedMessage>> {
+    const result = new Map<string, Array<SourceExtractedMessage>>();
     for (const message of messages) {
       const messagesById = result.get(message.id);
       if (messagesById) {
@@ -429,7 +429,7 @@ export default class CatalogManager implements Disposable {
   }
 
   private mergeDescriptions(
-    messages: Array<SourceMessage>
+    messages: Array<SourceExtractedMessage>
   ): ExtractorMessage['description'] {
     const sortedByReference = messages.toSorted((a, b) =>
       compareReferences(a.reference, b.reference)
@@ -447,8 +447,8 @@ export default class CatalogManager implements Disposable {
   }
 
   private haveMessagesChangedForFile(
-    beforeMessages: Map<string, Array<SourceMessage>> | undefined,
-    afterMessages: Map<string, Array<SourceMessage>>
+    beforeMessages: Map<string, Array<SourceExtractedMessage>> | undefined,
+    afterMessages: Map<string, Array<SourceExtractedMessage>>
   ): boolean {
     // If one exists and the other doesn't, there's a change
     if (!beforeMessages) {
@@ -481,8 +481,8 @@ export default class CatalogManager implements Disposable {
   }
 
   private areSourceMessageArraysEqual(
-    messages1: Array<SourceMessage>,
-    messages2: Array<SourceMessage>
+    messages1: Array<SourceExtractedMessage>,
+    messages2: Array<SourceExtractedMessage>
   ): boolean {
     return (
       messages1.length === messages2.length &&
@@ -493,8 +493,8 @@ export default class CatalogManager implements Disposable {
   }
 
   private areSourceMessagesEqual(
-    msg1: SourceMessage,
-    msg2: SourceMessage
+    msg1: SourceExtractedMessage,
+    msg2: SourceExtractedMessage
   ): boolean {
     return (
       msg1.id === msg2.id &&

packages/next-intl/src/extractor/extractor/MessageExtractor.tsx

@@ -1,7 +1,7 @@
 import {createRequire} from 'module';
 import path from 'path';
 import {transform} from '@swc/core';
-import type {SourceMessage} from '../types.js';
+import type {SourceExtractedMessage} from '../types.js';
 import {getDefaultProjectRoot, normalizePathToPosix} from '../utils.js';
 import LRUCache from './LRUCache.js';
 
@@ -12,7 +12,7 @@ export default class MessageExtractor {
   private projectRoot: string;
   private sourceMap: boolean;
   private compileCache = new LRUCache<{
-    messages: Array<SourceMessage>;
+    messages: Array<SourceExtractedMessage>;
     code: string;
     map?: string;
   }>(750);
@@ -31,7 +31,7 @@ export default class MessageExtractor {
     absoluteFilePath: string,
     source: string
   ): Promise<{
-    messages: Array<SourceMessage>;
+    messages: Array<SourceExtractedMessage>;
     code: string;
     map?: string;
   }> {
@@ -79,9 +79,20 @@ export default class MessageExtractor {
 
     // TODO: Improve the typing of @swc/core
     const output = (result as any).output as string;
-    const messages = JSON.parse(
-      JSON.parse(output).results
-    ) as Array<SourceMessage>;
+    // The plugin emits a tagged union of extracted messages and
+    // `useTranslations` usages; this extractor only consumes the former.
+    const messages = (
+      JSON.parse(JSON.parse(output).results) as Array<
+        {type: 'extracted' | 'translation'} & SourceExtractedMessage
+      >
+    )
+      .filter((item) => item.type === 'extracted')
+      .map((item) => ({
+        id: item.id,
+        message: item.message,
+        description: item.description,
+        reference: item.reference
+      }));
 
     const extractionResult = {
       code: result.code,

packages/next-intl/src/extractor/types.tsx

@@ -11,7 +11,7 @@ export type ExtractorMessageReference = {
 };
 
 /** A single statically extracted source-code usage before any aggregation. */
-export type SourceMessage = {
+export type SourceExtractedMessage = {
   id: string;
   message: string;
   description: string | null;