Clear trigger characters when restarting server (#1375)

Fixes #1372

Author: thecrypticace

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

@@ -929,7 +929,13 @@ export class TW {
     }
 
     // If the trigger characters haven't changed then we don't need to do anything
-    if (equal(Array.from(chars), Array.from(this.lastTriggerCharacters ?? []))) return
+    if (
+      this.completionRegistration &&
+      equal(Array.from(chars), Array.from(this.lastTriggerCharacters ?? []))
+    ) {
+      return
+    }
+
     this.lastTriggerCharacters = chars
 
     this.completionRegistration?.dispose()
@@ -1127,6 +1133,7 @@ export class TW {
     this.commonRegistrations?.dispose()
     this.commonRegistrations = undefined
 
+    this.lastTriggerCharacters.clear()
     this.completionRegistration?.dispose()
     this.completionRegistration = undefined
 

packages/tailwindcss-language-server/tests/env/capabilities.test.ts

@@ -182,3 +182,65 @@ defineTest({
     expect(idsBefore).toEqual(idsAfter)
   },
 })
+
+defineTest({
+  name: 'Trigger characters are registered after a server restart',
+  fs: {
+    'app.css': '@import "tailwindcss"',
+  },
+  prepare: async ({ root }) => ({ client: await createClient({ root }) }),
+  handle: async ({ root, client }) => {
+    // Initially don't have any registered capabilities because dynamic
+    // registration is delayed until after project initialization
+    expect(client.serverCapabilities).toEqual([])
+
+    // We open a document so a project gets initialized
+    await client.open({
+      lang: 'html',
+      text: '<div class="bg-[#000]/25 hover:">',
+    })
+
+    // And now capabilities are registered
+    expect(client.serverCapabilities).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          method: 'textDocument/hover',
+        }),
+
+        expect.objectContaining({
+          method: 'textDocument/completion',
+          registerOptions: {
+            documentSelector: null,
+            resolveProvider: true,
+            triggerCharacters: ['"', "'", '`', ' ', '.', '(', '[', ']', '!', '/', '-', ':'],
+          },
+        }),
+      ]),
+    )
+
+    let didRestart = new Promise((resolve) => {
+      client.conn.onNotification('@/tailwindCSS/serverRestarted', resolve)
+    })
+
+    // Force a server restart by telling the server tsconfig.json changed
+    client.notifyChangedFiles({
+      changed: [`${root}/tsconfig.json`],
+    })
+
+    // Wait for the server initialization to finish
+    await didRestart
+
+    expect(client.serverCapabilities).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          method: 'textDocument/completion',
+          registerOptions: {
+            documentSelector: null,
+            resolveProvider: true,
+            triggerCharacters: ['"', "'", '`', ' ', '.', '(', '[', ']', '!', '/', '-', ':'],
+          },
+        }),
+      ]),
+    )
+  },
+})