fix(native-preview): guard unterminated surrogate literals

Author: TorinAsakura

internal/api/encoder/encoder_test.go

@@ -75,6 +75,21 @@ func TestEncodeSourceFilePreservesSurrogateEscapes(t *testing.T) {
 	})
 }
 
+func TestEncodeSourceFileFallsBackForUnterminatedSurrogateEscape(t *testing.T) {
+	t.Parallel()
+	sourceFile := parser.ParseSourceFile(ast.SourceFileParseOptions{
+		FileName: "/test.ts",
+		Path:     "/test.ts",
+	}, `let s = "\uD800a`, core.ScriptKindTS)
+
+	buf, err := encoder.EncodeSourceFile(sourceFile)
+	assert.NilError(t, err)
+
+	text, ok := findExtendedNodeText(buf, ast.KindStringLiteral)
+	assert.Assert(t, ok)
+	assert.DeepEqual(t, text, []byte("\ufffda"))
+}
+
 func BenchmarkEncodeSourceFile(b *testing.B) {
 	repo.SkipIfNoTypeScriptSubmodule(b)
 	filePath := filepath.Join(repo.TypeScriptSubmodulePath(), "src/compiler/checker.ts")

internal/api/encoder/literal_text.go

@@ -37,7 +37,7 @@ func rawQuotedLiteralText(node *ast.Node, strs *stringTable) (string, bool) {
 	}
 	switch strs.fileText[start] {
 	case '\'', '"', '`':
-		if node.End()-start < 2 {
+		if node.End()-start < 2 || strs.fileText[node.End()-1] != strs.fileText[start] {
 			return "", false
 		}
 		return strs.fileText[start:node.End()], true