Refactor server testing infra

This builds out completely new APIs for testing language servers as well as stubs itself into the existing infra so the existing tests can be migrated incrementally

Author: thecrypticace

packages/tailwindcss-language-server/src/testing/index.ts

@@ -1,4 +1,4 @@
-import { afterAll, onTestFinished, test, TestOptions } from 'vitest'
+import { onTestFinished, test, TestOptions } from 'vitest'
 import * as fs from 'node:fs/promises'
 import * as path from 'node:path'
 import * as proc from 'node:child_process'
@@ -16,7 +16,7 @@ export interface Storage {
 
 export interface TestConfig<Extras extends {}> {
   name: string
-  fs: Storage
+  fs?: Storage
   prepare?(utils: TestUtils): Promise<Extras>
   handle(utils: TestUtils & Extras): void | Promise<void>
 
@@ -43,8 +43,10 @@ async function setup<T>(config: TestConfig<T>): Promise<TestUtils> {
 
   await fs.mkdir(baseDir, { recursive: true })
 
-  await prepareFileSystem(baseDir, config.fs)
-  await installDependencies(baseDir, config.fs)
+  if (config.fs) {
+    await prepareFileSystem(baseDir, config.fs)
+    await installDependencies(baseDir, config.fs)
+  }
 
   onTestFinished(async (result) => {
     // Once done, move all the files to a new location

packages/tailwindcss-language-server/src/tw.ts

@@ -664,6 +664,11 @@ export class TW {
         }),
       )
     }
+
+    // TODO: This is a hack and shouldn't be necessary
+    if (isTestMode) {
+      await this.connection.sendNotification('@/tailwindCSS/serverReady')
+    }
   }
 
   private filterNewWatchPatterns(patterns: string[]) {