fix: read stdout/stderr in parallel (#59)

Some nonsense happens when you read one after the other, which sometimes
results in one never closing (the for loop never ends).

This fixes it by running both in parallel.

Author: 43081j

src/main.ts

@@ -96,6 +96,14 @@ function combineSignals(signals: Iterable<AbortSignal>): AbortSignal {
   return controller.signal;
 }
 
+async function readStream(stream: Readable): Promise<string> {
+  let output = '';
+  for await (const chunk of stream) {
+    output += chunk.toString();
+  }
+  return output;
+}
+
 export class ExecProcess implements Result {
   protected _process?: ChildProcess;
   protected _aborted: boolean = false;
@@ -210,20 +218,10 @@ export class ExecProcess implements Result {
       throw new Error('No process was started');
     }
 
-    let stderr = '';
-    let stdout = '';
-
-    if (this._streamOut) {
-      for await (const chunk of this._streamOut) {
-        stdout += chunk.toString();
-      }
-    }
-
-    if (this._streamErr) {
-      for await (const chunk of this._streamErr) {
-        stderr += chunk.toString();
-      }
-    }
+    const [stdout, stderr] = await Promise.all([
+      this._streamOut ? readStream(this._streamOut) : '',
+      this._streamErr ? readStream(this._streamErr) : ''
+    ]);
 
     await this._processClosed;