add notification handlers

Author: Brad Cornes

package-lock.json

@@ -91,6 +91,7 @@
     "import-from": "^3.0.0",
     "jest": "^25.5.4",
     "line-column": "^1.0.2",
+    "mitt": "^1.2.0",
     "mkdirp": "^1.0.3",
     "pkg-up": "^3.1.0",
     "postcss": "^7.0.27",

package.json

@@ -21,6 +21,7 @@ import { registerConfigErrorHandler } from './lib/registerConfigErrorHandler'
 import { DEFAULT_LANGUAGES } from './lib/languages'
 import isObject from './util/isObject'
 import { dedupe, equal } from './util/array'
+import { createEmitter } from './lib/emitter'
 
 const CLIENT_ID = 'tailwindcss-intellisense'
 const CLIENT_NAME = 'Tailwind CSS IntelliSense'
@@ -147,7 +148,8 @@ export function activate(context: ExtensionContext) {
     )
 
     client.onReady().then(() => {
-      registerConfigErrorHandler(client)
+      let emitter = createEmitter(client)
+      registerConfigErrorHandler(emitter)
     })
 
     client.start()

src/extension.ts

@@ -0,0 +1,50 @@
+import mitt from 'mitt'
+import { LanguageClient } from 'vscode-languageclient'
+import crypto from 'crypto'
+
+export interface NotificationEmitter {
+  on: (name: string, handler: (args: any) => void) => void
+  off: (name: string, handler: (args: any) => void) => void
+  emit: (name: string, args: any) => Promise<any>
+}
+
+export function createEmitter(client: LanguageClient): NotificationEmitter {
+  const emitter = mitt()
+  const registered: string[] = []
+
+  const on = (name: string, handler: (args: any) => void) => {
+    if (!registered.includes(name)) {
+      registered.push(name)
+      client.onNotification(`tailwindcss/${name}`, (args) =>
+        emitter.emit(name, args)
+      )
+    }
+    emitter.on(name, handler)
+  }
+
+  const off = (name: string, handler: (args: any) => void) => {
+    emitter.off(name, handler)
+  }
+
+  const emit = (name: string, params: any) => {
+    return new Promise((resolve, _reject) => {
+      const id = crypto.randomBytes(16).toString('hex')
+      on(`${name}Response`, (result) => {
+        const { _id, ...rest } = result
+        if (_id === id) {
+          resolve(rest)
+        }
+      })
+      client.sendNotification(`tailwindcss/${name}`, {
+        _id: id,
+        ...params,
+      })
+    })
+  }
+
+  return {
+    on,
+    off,
+    emit,
+  }
+}

src/lib/emitter.ts

@@ -1,23 +1,20 @@
-import { LanguageClient } from 'vscode-languageclient'
 import { window, Uri, Range, Position } from 'vscode'
+import { NotificationEmitter } from './emitter'
 
-export function registerConfigErrorHandler(client: LanguageClient) {
-  client.onNotification(
-    'tailwindcss/configError',
-    async ({ message, file, line }) => {
-      const actions: string[] = file ? ['View'] : []
-      const action = await window.showErrorMessage(
-        `Tailwind CSS: ${message}`,
-        ...actions
-      )
-      if (action === 'View') {
-        window.showTextDocument(Uri.file(file), {
-          selection: new Range(
-            new Position(line - 1, 0),
-            new Position(line - 1, 0)
-          ),
-        })
-      }
+export function registerConfigErrorHandler(emitter: NotificationEmitter) {
+  emitter.on('configError', async ({ message, file, line }) => {
+    const actions: string[] = file ? ['View'] : []
+    const action = await window.showErrorMessage(
+      `Tailwind CSS: ${message}`,
+      ...actions
+    )
+    if (action === 'View') {
+      window.showTextDocument(Uri.file(file), {
+        selection: new Range(
+          new Position(line - 1, 0),
+          new Position(line - 1, 0)
+        ),
+      })
     }
-  )
+  })
 }

src/lib/registerConfigErrorHandler.ts

@@ -0,0 +1,15 @@
+import { Connection } from 'vscode-languageserver'
+
+export function onMessage(
+  connection: Connection,
+  name: string,
+  handler: (params: any) => any
+): void {
+  connection.onNotification(`tailwindcss/${name}`, async (params: any) => {
+    const { _id, ...rest } = params
+    connection.sendNotification(`tailwindcss/${name}Response`, {
+      _id,
+      ...(await handler(rest)),
+    })
+  })
+}