Cancel initial file search if it takes too long (#1242)

Fixes #986 (hopefully)

There's a lot of detail about the problem in the linked issue and my
response at the bottom. But briefly:
- Searches can take way too long; even spinning "forever" for some
people
- This occurs more often if following symlinks is enabled in VSCode
- We can cancel in-flight searches

This PR starts the searches and cancels them after ~15s. If the
extension hasn't found anything within 15s then it's likely it'll take
~15s any time you open that project and that would've been an absolutely
horrible dev experience that we probably would've been notified about.

It seems reasonable to set a time limit on the search do determine if we
need to start a language server

Author: thecrypticace

packages/vscode-tailwindcss/CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Prerelease
 
 - v4: Support loading bundled versions of some first-party plugins ([#1240](https://github.com/tailwindlabs/tailwindcss-intellisense/pull/1240))
+- Cancel initial file search if it takes too long ([#1242](https://github.com/tailwindlabs/tailwindcss-intellisense/pull/1242))
 
 # 0.14.8
 

packages/vscode-tailwindcss/src/extension.ts

@@ -6,6 +6,7 @@ import type {
   ConfigurationScope,
   WorkspaceConfiguration,
   Selection,
+  CancellationToken,
 } from 'vscode'
 import {
   workspace as Workspace,
@@ -16,6 +17,7 @@ import {
   Position,
   Range,
   RelativePattern,
+  CancellationTokenSource,
 } from 'vscode'
 import type {
   DocumentFilter,
@@ -581,26 +583,45 @@ export async function activate(context: ExtensionContext) {
       return
     }
 
-    if (!(await anyFolderNeedsLanguageServer(Workspace.workspaceFolders ?? []))) {
+    let source: CancellationTokenSource | null = new CancellationTokenSource()
+    source.token.onCancellationRequested(() => {
+      source?.dispose()
+      source = null
+      outputChannel.appendLine(
+        'Server was not started. Search for Tailwind CSS-related files was taking too long.',
+      )
+    })
+
+    // Cancel the search after roughly 15 seconds
+    setTimeout(() => source?.cancel(), 15_000)
+
+    if (!(await anyFolderNeedsLanguageServer(Workspace.workspaceFolders ?? [], source!.token))) {
+      source?.dispose()
       return
     }
 
+    source?.dispose()
+
     await bootWorkspaceClient()
   }
 
   async function anyFolderNeedsLanguageServer(
     folders: readonly WorkspaceFolder[],
+    token: CancellationToken,
   ): Promise<boolean> {
     for (let folder of folders) {
-      if (await folderNeedsLanguageServer(folder)) {
+      if (await folderNeedsLanguageServer(folder, token)) {
         return true
       }
     }
 
     return false
   }
 
-  async function folderNeedsLanguageServer(folder: WorkspaceFolder): Promise<boolean> {
+  async function folderNeedsLanguageServer(
+    folder: WorkspaceFolder,
+    token: CancellationToken,
+  ): Promise<boolean> {
     let settings = Workspace.getConfiguration('tailwindCSS', folder)
     if (settings.get('experimental.configFile') !== null) {
       return true
@@ -616,13 +637,19 @@ export async function activate(context: ExtensionContext) {
       new RelativePattern(folder, `**/${CONFIG_GLOB}`),
       exclude,
       1,
+      token,
     )
 
     for (let file of configFiles) {
       return true
     }
 
-    let cssFiles = await Workspace.findFiles(new RelativePattern(folder, `**/${CSS_GLOB}`), exclude)
+    let cssFiles = await Workspace.findFiles(
+      new RelativePattern(folder, `**/${CSS_GLOB}`),
+      exclude,
+      undefined,
+      token,
+    )
 
     for (let file of cssFiles) {
       outputChannel.appendLine(`Checking if ${file.fsPath} may be Tailwind-related…`)