fix: sync error in onceOutputLine callback should cause async rejection

Author: zenflow

src/createReadyContext.ts

@@ -2,6 +2,7 @@ import { promisify } from "util";
 import stream from "stream";
 import { ReadyContext } from "./interfaces/ReadyContext";
 import { onceTcpPortUsed } from "./util/onceTcpPortUsed";
+import { onceOutputLine } from "./util/onceOutputLine";
 
 const delay = promisify(setTimeout);
 
@@ -14,15 +15,3 @@ export function createReadyContext(output: stream.Readable): ReadyContext {
     onceDelay: milliseconds => delay(milliseconds),
   };
 }
-
-function onceOutputLine(output: stream.Readable, test: (line: string) => boolean): Promise<void> {
-  return new Promise<void>(resolve => {
-    const handler = (line: string) => {
-      if (test(line)) {
-        output.off("data", handler);
-        resolve();
-      }
-    };
-    output.on("data", handler);
-  });
-}

src/util/onceOutputLine.ts

@@ -0,0 +1,25 @@
+import stream from "stream";
+
+export function onceOutputLine(
+  output: stream.Readable,
+  test: (line: string) => boolean,
+): Promise<void> {
+  return new Promise<void>((resolve, reject) => {
+    const handler = (line: string) => {
+      let testResult = false;
+      try {
+        testResult = test(line);
+      } catch (error) {
+        cleanup();
+        reject(error);
+        return;
+      }
+      if (testResult) {
+        cleanup();
+        resolve();
+      }
+    };
+    output.on("data", handler);
+    const cleanup = () => output.off("data", handler);
+  });
+}