chore: swap mocha with vitest (#8584)

Also swap out the require hook hacks with a less-hacky-but-still-somewhat-hacky loader for the Svelte files

---------

Co-authored-by: Simon Holthausen <[email protected]>
Co-authored-by: Rich Harris <[email protected]>

Author: 3 people

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
           cache: pnpm
       - run: pnpm install --frozen-lockfile
       - run: pnpm playwright install chromium
-      - run: pnpm test:integration
+      - run: pnpm test
         env:
           CI: true
   Lint:
@@ -50,28 +50,3 @@ jobs:
           node-version: 16
           cache: pnpm
       - run: 'pnpm i && pnpm format:check && pnpm lint'
-  Unit:
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 10
-    strategy:
-      matrix:
-        include:
-          - node-version: 16
-            os: ubuntu-latest
-          - node-version: 16
-            os: windows-latest
-          - node-version: 16
-            os: macOS-latest
-          - node-version: 18
-            os: ubuntu-latest
-          - node-version: 20
-            os: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: pnpm/[email protected]
-      - uses: actions/setup-node@v3
-        with:
-          node-version: ${{ matrix.node-version }}
-          cache: pnpm
-      - run: pnpm install
-      - run: pnpm test:unit

.mocharc.js

@@ -10,4 +10,5 @@ src/compiler/compile/internal_exports.ts
 /test/**/_expected*
 /test/**/_actual*
 /test/**/expected*
+/test/**/_output
 /types

.mocharc.unit.js

@@ -0,0 +1,47 @@
+import { existsSync, fstat, readFileSync, readdirSync, writeFileSync } from 'fs';
+import { resolve } from 'path';
+import { parse } from 'acorn';
+import { walk } from 'estree-walker';
+import { inspect } from 'util';
+
+import { p, print } from 'code-red';
+
+const samples = resolve(`vitest/runtime/runtime/samples`);
+
+for (const dir of readdirSync(samples)) {
+	const cwd = resolve(samples, dir);
+	const file = resolve(cwd, '_config.js');
+
+	if (!existsSync(file)) continue;
+	const contents = readFileSync(file, 'utf-8');
+	const ast = parse(contents, {
+		sourceType: 'module',
+		ecmaVersion: 'latest',
+		sourceFile: file,
+		ranges: true
+	});
+
+	walk(ast, {
+		enter(node) {
+			if (
+				node.type === 'ExportDefaultDeclaration' &&
+				node.declaration.type === 'ObjectExpression'
+			) {
+				this.skip();
+
+				const props = node.declaration.properties.find((prop) => prop.key.name === 'props');
+				if (!props) return;
+				const { range } = props;
+
+				const [start, end] = range;
+
+				const code =
+					contents.slice(0, start) +
+					print(p`get ${props.key}() { return ${props.value}}`).code +
+					contents.slice(end);
+                
+                writeFileSync(file, code);
+			}
+		}
+	});
+}

.prettierignore

@@ -83,10 +83,7 @@
   "scripts": {
     "format:fix": "prettier . --cache --plugin-search-dir=. --write",
     "format:check": "prettier . --cache --plugin-search-dir=. --check",
-    "test": "npm run test:unit && npm run test:integration && echo \"manually check that there are no type errors in test/types by opening the files in there\"",
-    "test:integration": "mocha --exit",
-    "test:unit": "mocha --config .mocharc.unit.js --exit",
-    "quicktest": "mocha --exit",
+    "test": "vitest run && echo \"manually check that there are no type errors in test/types by opening the files in there\"",
     "build": "rollup -c && npm run tsd",
     "prepare": "npm run build",
     "dev": "rollup -cw",
@@ -140,12 +137,12 @@
     "eslint-plugin-import": "^2.27.5",
     "eslint-plugin-svelte3": "^4.0.0",
     "estree-walker": "^3.0.3",
+    "happy-dom": "^9.18.3",
     "is-reference": "^3.0.1",
     "jsdom": "^21.1.1",
     "kleur": "^4.1.5",
     "locate-character": "^2.0.5",
     "magic-string": "^0.30.0",
-    "mocha": "^10.2.0",
     "periscopic": "^3.1.0",
     "prettier": "^2.8.8",
     "prettier-plugin-svelte": "^2.10.0",
@@ -155,7 +152,8 @@
     "tiny-glob": "^0.2.9",
     "tslib": "^2.5.0",
     "typescript": "^5.0.4",
-    "util": "^0.12.5"
+    "util": "^0.12.5",
+    "vitest": "^0.31.0"
   },
   "packageManager": "[email protected]"
 }