Fixed bug in extraction if string is followed by comma

Author: Shin--

src/extract/parser.ts

@@ -44,7 +44,7 @@ export function parseFunctionCall(mapping: KeywordMapping, tokens: Token[]): Msg
 
     // parse strings arguments
     while (true) {
-      if (t.kind !== TokenKind.String) {
+      if (!t || t.kind !== TokenKind.String) {
         break;
       }
       assertIsDefined(t.value);

tests/extract.test.ts

@@ -0,0 +1,61 @@
+import { mkdir, mkdtemp, readFile, rm, symlink, writeFile } from "fs/promises";
+import { join } from "path";
+import { tmpdir } from "os";
+import { cwd } from "process";
+import { execSync } from "child_process";
+import { describe, it, expect } from "vitest";
+
+describe("Extractor Script Tests", () => {
+  type WithTempDirTest = (tmpDir: string) => Promise<any>;
+
+  // This helper function is copied directly from config.test.ts
+  const withTempDir = async (testFunc: WithTempDirTest) => {
+    let tmpDir;
+    try {
+      tmpDir = await mkdtemp(join(tmpdir(), "vue3-gettext-extract-"));
+      await testFunc(tmpDir);
+    } finally {
+      if (tmpDir) {
+        await rm(tmpDir, { recursive: true, force: true });
+      }
+    }
+  };
+
+  it("should correctly extract a message from a $gettext call with a trailing comma", async () => {
+    await withTempDir(async (tmpDir) => {
+      // 1. Setup the project structure inside the temp directory
+      for (const d of ["src", "scripts", "node_modules"]) {
+        await symlink(join(cwd(), d), join(tmpDir, d));
+      }
+      await writeFile(join(tmpDir, "package.json"), JSON.stringify({ name: "test", type: "commonjs" }));
+
+      await writeFile(
+        join(tmpDir, "gettext.config.js"),
+        `module.exports = { input: { path: './srctest' }, output: { path: './srctest/lang' } };`,
+      );
+
+      await mkdir(join(tmpDir, "srctest", "lang"), { recursive: true });
+      await writeFile(
+        join(tmpDir, "srctest", "MultiLineLiteralWithComma.js"),
+        `
+          const myText = $gettext(
+            \`This is a multiline template literal,
+              That previously caused a crash in extraction.\`,
+          );
+        `,
+      );
+
+      execSync(`sh -c 'cd ${tmpDir}; tsx ./scripts/gettext_extract.ts'`);
+
+      // Verify that the output .pot file is correct.
+      const potContent = (await readFile(join(tmpDir, "srctest", "lang", "messages.pot"))).toString();
+      console.debug(potContent);
+      expect(potContent).toContain(
+        'msgid ""\n' +
+          '"This is a multiline template literal,\\n"\n' +
+          '"              That previously caused a crash in extraction."\n',
+      );
+      expect(potContent).toContain("#: srctest/MultiLineLiteralWithComma.js:2");
+    });
+  });
+});