BridgeJS: Improve ts2swift diagnostics on invalid definitions

```
$ cat /tmp/tmp.UUlUCtSa64/foo.d.ts
export function x(): ;

$ node Plugins/BridgeJS/Sources/TS2Swift/JavaScript/bin/ts2swift.js /tmp/tmp.UUlUCtSa64/foo.d.ts
error: TypeScript syntax errors:
/tmp/tmp.UUlUCtSa64/foo.d.ts:1:22 - error TS1110: Type expected.

1 export function x(): ;
```

Author: kateinoigakukun

Plugins/BridgeJS/Sources/TS2Swift/JavaScript/src/cli.js

@@ -122,14 +122,30 @@ export function run(filePaths, options) {
     }
 
     const program = TypeProcessor.createProgram([...filePaths, ...globalFiles], configParseResult.options);
-    const diagnostics = program.getSemanticDiagnostics();
-    if (diagnostics.length > 0) {
+
+    const formatDiagnostics = (diagnostics, kind) => {
+        if (diagnostics.length === 0) return null;
         const message = ts.formatDiagnosticsWithColorAndContext(diagnostics, {
             getCanonicalFileName: (fileName) => fileName,
             getNewLine: () => ts.sys.newLine,
             getCurrentDirectory: () => ts.sys.getCurrentDirectory(),
         });
-        throw new Error(`TypeScript semantic errors:\n${message}`);
+        return `${kind} errors:\n${message}`;
+    };
+
+    const syntaxErrors = formatDiagnostics(program.getSyntacticDiagnostics(), "TypeScript syntax");
+    if (syntaxErrors) {
+        throw new Error(syntaxErrors);
+    }
+
+    const optionErrors = formatDiagnostics(program.getOptionsDiagnostics(), "TypeScript option");
+    if (optionErrors) {
+        throw new Error(optionErrors);
+    }
+
+    const semanticErrors = formatDiagnostics(program.getSemanticDiagnostics(), "TypeScript semantic");
+    if (semanticErrors) {
+        throw new Error(semanticErrors);
     }
 
     const prelude = [
@@ -244,6 +260,13 @@ export function main(args) {
             cleanup();
         }
     }
+
+    if (swiftOutput.length === 0) {
+        diagnosticEngine.print(
+            "warning",
+            "No Swift declarations were generated. This usually means the .d.ts contained constructs that BridgeJS cannot import."
+        );
+    }
     // Write to file or stdout
     if (options.values.output && options.values.output !== "-") {
         if (swiftOutput.length > 0) {

Plugins/BridgeJS/Sources/TS2Swift/JavaScript/test/ts2swift.test.js

@@ -1,8 +1,9 @@
 // @ts-check
 import { describe, it, expect } from 'vitest';
-import { readdirSync } from 'fs';
+import { readdirSync, mkdtempSync, writeFileSync, rmSync } from 'fs';
 import { fileURLToPath } from 'url';
 import path from 'path';
+import os from 'os';
 import { run } from '../src/cli.js';
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
@@ -38,4 +39,15 @@ describe('ts2swift', () => {
             expect(swiftOutput).toMatchSnapshot(name);
         });
     }
+
+    it('reports TypeScript syntax errors via thrown message', () => {
+        const tmpDir = mkdtempSync(path.join(os.tmpdir(), 'ts2swift-invalid-'));
+        const invalidPath = path.join(tmpDir, 'invalid.d.ts');
+        writeFileSync(invalidPath, 'function foo(x');
+        try {
+            expect(() => runTs2Swift(invalidPath)).toThrowError(/TypeScript syntax errors/);
+        } finally {
+            rmSync(tmpDir, { recursive: true, force: true });
+        }
+    });
 });