feat: factor out child process handling

Author: HerringtonDarkholme

src/view.ts

@@ -18,41 +18,47 @@ export function activate(context: vscode.ExtensionContext) {
 
 let child: ChildProcessWithoutNullStreams | undefined
 
-async function getPatternRes(pattern: string) {
-  if (!pattern) {
-    return
-  }
-  let command = workspace
-    .getConfiguration('astGrep')
-    .get('serverPath', 'ast-grep')
-  const uris = workspace.workspaceFolders?.map(i => i.uri?.fsPath) ?? []
-
-  // TODO: multi-workspaces support
-  // TODO: the code here is wrong, but we will change it
+function streamedPromise(
+  proc: ChildProcessWithoutNullStreams
+): Promise<string> {
   let stdout = ''
   if (child) {
     // kill previous search
     child.kill('SIGTERM')
   }
-  child = spawn(command, ['run', '--pattern', pattern, '--json=compact'], {
-    cwd: uris[0]
-  })
+  child = proc
   child.stdout.on('data', data => {
     stdout += data
   })
-  await new Promise((resolve, reject) =>
+  return new Promise((resolve, reject) =>
     child!.on('exit', (code, signal) => {
       // exit without signal, search ends correctly
       // TODO: is it correct now?
       if (!signal && code === 0) {
-        resolve(code)
+        child = undefined
+        resolve(stdout)
       } else {
         reject([code, signal])
       }
     })
   )
-  child = undefined
+}
 
+async function getPatternRes(pattern: string) {
+  if (!pattern) {
+    return
+  }
+  let command = workspace
+    .getConfiguration('astGrep')
+    .get('serverPath', 'ast-grep')
+  const uris = workspace.workspaceFolders?.map(i => i.uri?.fsPath) ?? []
+
+  // TODO: multi-workspaces support
+  // TODO: the code here is wrong, but we will change it
+  let proc = spawn(command, ['run', '--pattern', pattern, '--json=compact'], {
+    cwd: uris[0]
+  })
+  const stdout = await streamedPromise(proc)
   try {
     let res: SgSearch[] = JSON.parse(stdout)
     return res