github
diff --git a/‎lib/testing-utils.js‎
Lines changed: 20 additions & 3 deletions b/‎lib/testing-utils.js‎
Lines changed: 20 additions & 3 deletions
diff --git a/‎lib/testing-utils.js.map‎
Lines changed: 1 addition & 1 deletion b/‎lib/testing-utils.js.map‎
Lines changed: 1 addition & 1 deletion
diff --git a/‎src/testing-utils.ts‎
Lines changed: 24 additions & 5 deletions b/‎src/testing-utils.ts‎
Lines changed: 24 additions & 5 deletions
@@ -3,10 +3,29 @@ import {TestInterface} from 'ava';
 type TestContext = {stdoutWrite: any, stderrWrite: any, testOutput: string};
 
 function wrapOutput(context: TestContext) {
-  return (str: any): boolean => {
-    if (typeof str === 'string') {
-      context.testOutput += str;
+  // Function signature taken from Socket.write.
+  // Note there are two overloads:
+  // write(buffer: Uint8Array | string, cb?: (err?: Error) => void): boolean;
+  // write(str: Uint8Array | string, encoding?: string, cb?: (err?: Error) => void): boolean;
+  return (chunk: Uint8Array | string, encoding?: string, cb?: (err?: Error) => void): boolean => {
+    // Work out which method overload we are in
+    if (cb === undefined && typeof encoding === 'function') {
+      cb = encoding;
+      encoding = undefined;
     }
+
+    // Record the output
+    if (typeof chunk === 'string') {
+      context.testOutput += chunk;
+    } else {
+      context.testOutput += new TextDecoder(encoding || 'utf-8').decode(chunk);
+    }
+
+    // Satisfy contract by calling callback when done
+    if (cb !== undefined && typeof cb === 'function') {
+      cb();
+    }
+
     return true;
   };
 }
@@ -19,11 +38,11 @@ export function silenceDebugOutput(test: TestInterface<any>) {
 
       const processStdoutWrite = process.stdout.write.bind(process.stdout);
       t.context.stdoutWrite = processStdoutWrite;
-      process.stdout.write = wrapOutput(t.context);
+      process.stdout.write = wrapOutput(t.context) as any;
 
       const processStderrWrite = process.stderr.write.bind(process.stderr);
       t.context.stderrWrite = processStderrWrite;
-      process.stderr.write = wrapOutput(t.context);
+      process.stderr.write = wrapOutput(t.context) as any;
   });
 
   typedTest.afterEach.always(t => {