Add jest-extended back

.vscode/settings.json

@@ -1,6 +1,7 @@
 {
     "cSpell.words": [
         "Asciinema",
+        "firstrun",
         "superstruct"
     ]
 }

package.json

@@ -48,6 +48,7 @@
 		"cross-fetch": "^4.0.0",
 		"eslint": "^8.56.0",
 		"eslint-plugin-svelte": "^2.35.1",
+		"jest-extended": "^4.0.2",
 		"simple-git": "^3.25.0",
 		"svelte": "^4.2.7",
 		"svelte-check": "^3.6.0",

tests/setup/jestExtended.d.ts

@@ -0,0 +1,9 @@
+// https://jest-extended.jestcommunity.dev/docs/getting-started/setup#use-with-vitest
+import type CustomMatchers from 'jest-extended';
+import 'vitest';
+
+declare module 'vitest' {
+  interface Assertion<T = any> extends CustomMatchers<T> {}
+  interface AsymmetricMatchersContaining<T = any> extends CustomMatchers<T> {}
+  interface ExpectStatic extends CustomMatchers<T> {}
+}

tests/setup/jestExtended.ts

@@ -0,0 +1,4 @@
+// https://jest-extended.jestcommunity.dev/docs/getting-started/setup#use-with-vitest
+import { expect } from 'vitest';
+import * as matchers from 'jest-extended';
+expect.extend(matchers);

tsconfig.json

@@ -11,7 +11,8 @@
 		"strict": true,
 		"moduleResolution": "bundler",
 	},
-	"types": ["vitest/globals"]
+	// Add Jest extended to vitest
+	"files": ["tests/setup/jestExtended.d.ts"],
 	// Path aliases are handled by https://kit.svelte.dev/docs/configuration#alias
 	// except $lib which is handled by https://kit.svelte.dev/docs/configuration#files
 	//

vitest.config.ts

@@ -6,8 +6,12 @@ export default mergeConfig(defaultConfig, defineConfig({
     // globals: true,
     setupFiles: [
       'tests/setup/serverBeforeEach.ts',
+      'tests/setup/jestExtended.ts',
     ],
     fileParallelism: false,
-    globalSetup: ['tests/setup/globalSetup.ts']
+    globalSetup: ['tests/setup/globalSetup.ts'],
+    sequence: {
+      concurrent: false,
+    }
   },
 }));