refactor: use typescript as parser instead of babel parser

packages/vite-plugin-doctest/package.json

@@ -41,14 +41,13 @@
 	"devDependencies": {
 		"remark-parse": "^10.0.2",
 		"tsup": "^7.2.0",
-		"typescript": "^5.2.2",
 		"unified": "^10.1.2",
 		"vite": "^4.4.9",
 		"vitest": "^0.34.0"
 	},
 	"dependencies": {
-		"@babel/parser": "^7.22.16",
 		"magic-string": "^0.30.3",
+		"typescript": "^4.0.0 || ^5.0.0",
 		"vite": "^4.0.0 || ^5.0.0-0"
 	}
 }

packages/vite-plugin-doctest/src/transformers/typescript.ts

@@ -1,17 +1,15 @@
-import { parse } from "@babel/parser";
 import MagicString from "magic-string";
-import { extractCode, extractTestComment, vitestExports } from "./utils";
+import typescript from "typescript";
+import { extractCode, vitestExports } from "./utils";
 
 export function transform(code: string, id: string) {
-	const comments =
-		parse(code, {
-			plugins: id.match(/\.[cm]?tsx?$/) ? ["typescript"] : [],
-			sourceType: "module",
-		}).comments ?? [];
-	const tests = comments
-		.filter((c) => c.type === "CommentBlock" && c.value.startsWith("*"))
-		.flatMap((c) => extractTestComment(c.value))
-		.flatMap(extractCode);
+	const node = typescript.createSourceFile(
+		id,
+		code,
+		typescript.ScriptTarget.ESNext,
+	);
+	const jsDocs = findJSDoc(node);
+	const tests = jsDocs.flatMap(extractTestComment).flatMap(extractCode);
 	if (tests.length === 0) return code;
 
 	const s = new MagicString(code);
@@ -36,3 +34,35 @@ export function transform(code: string, id: string) {
 		map: s.generateMap({ hires: true, source: id }),
 	};
 }
+
+function findJSDoc(node: typescript.Node): typescript.JSDoc[] {
+	const nodes: typescript.JSDoc[] = [];
+	// HACK: typescript.Node has no jsDoc property
+	if ("jsDoc" in node && Array.isArray(node.jsDoc) && node.jsDoc.length > 0) {
+		nodes.push(
+			...node.jsDoc.flatMap((doc) => (typescript.isJSDoc(doc) ? [doc] : [])),
+		);
+	}
+	node.forEachChild((child) => nodes.push(...findJSDoc(child)));
+	return nodes;
+}
+
+function extractTestComment(jsDoc: typescript.JSDoc): string[] {
+	return (
+		jsDoc.tags?.flatMap((tag) => {
+			if (tag.comment == null) return [];
+			const commentText =
+				typeof tag.comment === "string"
+					? tag.comment
+					: tag.comment.map((c) => c.text).join("\n");
+			// tagName should be `import.meta.vitest`. But it splits into `import` and `.meta.vitest`.
+			if (
+				tag.tagName.text === "import" &&
+				commentText.startsWith(".meta.vitest")
+			) {
+				return [commentText];
+			}
+			return [];
+		}) ?? []
+	);
+}

packages/vite-plugin-doctest/src/transformers/utils.ts

@@ -24,14 +24,6 @@ export const vitestExports = [
 	"vitest",
 ];
 
-export function extractTestComment(jsDoc: string): string[] {
-	const testTagMatcher = /^import\.meta\.vitest\b/;
-	if (!jsDoc.startsWith("*")) return [];
-	const tags = jsDoc.replace(/^[ \t]*\*[ \t]*/gm, "").split(/\n@/g).slice(1);
-	const testTags = tags.filter((tag) => tag.match(testTagMatcher));
-	return testTags.map((tagComment) => tagComment.replace(testTagMatcher, ""));
-}
-
 type TestCode = {
 	name?: string;
 	code: string;