test: add the sketchy transform back

Author: 43081j

scripts/transform-plugin.mjs

@@ -0,0 +1,92 @@
+import { fileURLToPath } from 'node:url';
+import path from 'node:path';
+import { transformAsync } from '@babel/core';
+
+export function createEsbuildPlugin() {
+	const pending = new Map();
+	const cache = new Map();
+	const __dirname = path.dirname(fileURLToPath(import.meta.url));
+	const projectRoot = path.resolve(__dirname, '..');
+
+	return {
+		name: 'react-transform',
+		enforce: 'pre',
+		async transform(code, id) {
+			if (id.includes("node_modules") ||
+					(!id.includes("packages/react/test/shared") &&
+					!id.includes("packages/react/runtime/test"))) {
+				return null;
+			}
+
+			if (!id.endsWith('.js') && !id.endsWith('.ts') && !id.endsWith('.jsx') && !id.endsWith('.tsx')) {
+				return null;
+			}
+
+			const cached = cache.get(id);
+
+			if (cached && cached.input === code) {
+				return {
+					code: cached.result,
+					map: null,
+				};
+			}
+
+			let result = code;
+
+			if (!pending.has(id)) {
+				pending.set(id, []);
+
+				const jsx = [
+					"@babel/preset-react",
+					{
+						runtime: "classic",
+						pragma: "createElement",
+						pragmaFrag: "Fragment",
+					},
+				];
+
+				const ts = [
+					"@babel/preset-typescript",
+					{
+						jsxPragma: "createElement",
+						jsxPragmaFrag: "Fragment",
+					},
+				];
+
+				const transformPath = path.join(projectRoot, "packages/react-transform");
+				const signalsTransform = [
+					transformPath,
+					{
+						mode: "auto",
+					},
+				];
+
+				const tmp = await transformAsync(result, {
+					filename: id,
+					sourceMaps: "inline",
+					presets: [ts, jsx],
+					plugins: [
+						signalsTransform,
+					],
+				});
+				result = (tmp && tmp.code) || result;
+				cache.set(id, { input: code, result });
+
+				const waited = pending.get(id);
+				pending.delete(id);
+				waited.forEach(fn => fn());
+			} else {
+				await new Promise(r => {
+					pending.get(id).push(r);
+				});
+				result = cache.get(id).result;
+			}
+
+			return {
+				code: result,
+				// TODO (43081j): will this mess sourcemaps up in tests?
+				map: null,
+			};
+		}
+	};
+}

vitest.config.mjs

@@ -1,5 +1,6 @@
 import { defineConfig } from 'vitest/config';
 import { manglePlugin } from './scripts/mangle-plugin.mjs';
+import { createEsbuildPlugin } from './scripts/transform-plugin.mjs';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
@@ -35,6 +36,7 @@ export default defineConfig({
 	},
 	plugins: [
 		manglePlugin,
+		createEsbuildPlugin()
 	],
 	// TODO (43081j): stop faking node globals and sort out the transform
 	// tests. Either run them in node, or somehow run babel in node but the