feat(linter/plugins): correctly transfer script type for tokens

apps/oxlint/src-js/generated/constants.ts

@@ -7,3 +7,6 @@ export const DATA_POINTER_POS_32 = 536870902;
 export const IS_TS_FLAG_POS = 2147483612;
 export const PROGRAM_OFFSET = 0;
 export const SOURCE_LEN_OFFSET = 16;
+export const SOURCE_TYPE_OFFSET = 124;
+export const SOURCE_TYPE_LANGUAGE_OFFSET = 0;
+export const SOURCE_TYPE_VARIANT_OFFSET = 2;

apps/oxlint/src-js/plugins/source_code.ts

@@ -1,4 +1,10 @@
-import { DATA_POINTER_POS_32, SOURCE_LEN_OFFSET } from "../generated/constants.ts";
+import {
+  DATA_POINTER_POS_32,
+  SOURCE_LEN_OFFSET,
+  SOURCE_TYPE_OFFSET,
+  SOURCE_TYPE_LANGUAGE_OFFSET,
+  SOURCE_TYPE_VARIANT_OFFSET,
+} from "../generated/constants.ts";
 
 // We use the deserializer which removes `ParenthesizedExpression`s from AST,
 // and with `range`, `loc`, and `parent` properties on AST nodes, to match ESLint
@@ -66,6 +72,32 @@ export function initSourceText(): void {
   sourceText = textDecoder.decode(buffer.subarray(0, sourceByteLen));
 }
 
+/**
+ * Check if the current source is JSX/TSX.
+ * Reads the `SourceType.variant` (LanguageVariant) from the Program in the buffer.
+ * @returns `true` if the source is JSX or TSX
+ */
+export function isJsxSource(): boolean {
+  debugAssertIsNonNull(buffer);
+  const { uint32 } = buffer,
+    programPos = uint32[DATA_POINTER_POS_32],
+    sourceTypePos = programPos + SOURCE_TYPE_OFFSET;
+  return buffer[sourceTypePos + SOURCE_TYPE_VARIANT_OFFSET] === 1;
+}
+
+/**
+ * Check if the current source is TypeScript.
+ * Reads the `SourceType.language` (Language) from the Program in the buffer.
+ * @returns `true` if the source is TypeScript or TypeScript Definition
+ */
+export function isTypescriptSource(): boolean {
+  debugAssertIsNonNull(buffer);
+  const { uint32 } = buffer,
+    programPos = uint32[DATA_POINTER_POS_32],
+    sourceTypePos = programPos + SOURCE_TYPE_OFFSET;
+  return buffer[sourceTypePos + SOURCE_TYPE_LANGUAGE_OFFSET] >= 1;
+}
+
 /**
  * Deserialize AST from buffer.
  */

apps/oxlint/src-js/plugins/tokens_parse.ts

@@ -5,7 +5,7 @@
 import { createRequire } from "node:module";
 import { filePath } from "./context.ts";
 import { getNodeLoc } from "./location.ts";
-import { sourceText } from "./source_code.ts";
+import { isJsxSource, isTypescriptSource, sourceText } from "./source_code.ts";
 import { debugAssert, debugAssertIsNonNull } from "../utils/asserts.ts";
 
 import type * as ts from "typescript";
@@ -51,6 +51,8 @@ export function parseTokens(): Token[] {
     tsSyntaxKind = tsModule.SyntaxKind;
   }
 
+  const scriptKind = getScriptKind();
+
   // Parse source text into TypeScript AST
   const tsAst = tsModule.createSourceFile(
     filePath,
@@ -62,8 +64,7 @@ export function parseTokens(): Token[] {
       setExternalModuleIndicator: undefined,
     },
     true, // `setParentNodes`
-    // TODO: Use `TS` or `TSX` depending on source type
-    tsModule.ScriptKind.TSX,
+    scriptKind,
   );
 
   // Check that TypeScript hasn't altered source text.
@@ -267,3 +268,20 @@ function hasJSXAncestor(node: ts.Node | undefined): boolean {
 function isJSXTokenKind(kind: ts.SyntaxKind): boolean {
   return kind >= tsSyntaxKind.JsxElement && kind <= tsSyntaxKind.JsxAttribute;
 }
+
+/**
+ * Determine TypeScript ScriptKind based on source type from the buffer.
+ * Reads the JSX flag from `SourceType.variant` and TypeScript flag from metadata.
+ *
+ * @returns Appropriate ScriptKind for the file
+ */
+function getScriptKind(): ts.ScriptKind {
+  debugAssertIsNonNull(tsModule);
+  const isJsx = isJsxSource();
+  const isTs = isTypescriptSource();
+
+  if (isTs) {
+    return isJsx ? tsModule.ScriptKind.TSX : tsModule.ScriptKind.TS;
+  }
+  return isJsx ? tsModule.ScriptKind.JSX : tsModule.ScriptKind.JS;
+}

apps/oxlint/test/fixtures/tokens/files/generic_arrow.ts

@@ -0,0 +1,8 @@
+const obj = {
+  fn: <T>(arg: T): T => {
+    return arg;
+  },
+};
+
+// A comment after the object
+export { obj };