From a7fa61ab2fc323372b889cab228cec3580e864fb Mon Sep 17 00:00:00 2001
From: smessie <smessie@users.noreply.github.com>
Date: Tue, 27 Oct 2020 15:17:59 +0100
Subject: [PATCH] fix: Resolve duplicate error message and no trailing newline

* fix: Resolves duplicate error message

* test: Add trailing newline on error test
---
 src/ldp/http/BasicResponseWriter.ts            |  4 +++-
 test/unit/ldp/http/BasicResponseWriter.test.ts | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/ldp/http/BasicResponseWriter.ts b/src/ldp/http/BasicResponseWriter.ts
index 569343c07..f62e5b3f6 100644
--- a/src/ldp/http/BasicResponseWriter.ts
+++ b/src/ldp/http/BasicResponseWriter.ts
@@ -27,7 +27,9 @@ export class BasicResponseWriter extends ResponseWriter {
       }
       input.response.setHeader('content-type', 'text/plain');
       input.response.writeHead(code);
-      input.response.end(`${input.result.name}: ${input.result.message}\n${input.result.stack}`);
+      input.response.end(typeof input.result.stack === 'string' ?
+        `${input.result.stack}\n` :
+        `${input.result.name}: ${input.result.message}\n`);
     } else {
       input.response.setHeader('location', input.result.identifier.path);
       if (input.result.body) {
diff --git a/test/unit/ldp/http/BasicResponseWriter.test.ts b/test/unit/ldp/http/BasicResponseWriter.test.ts
index 16a58d4f0..6796533a9 100644
--- a/test/unit/ldp/http/BasicResponseWriter.test.ts
+++ b/test/unit/ldp/http/BasicResponseWriter.test.ts
@@ -81,4 +81,19 @@ describe('A BasicResponseWriter', (): void => {
     expect(response._getStatusCode()).toBe(error.statusCode);
     expect(response._getData()).toMatch('UnsupportedHttpError: error');
   });
+
+  it('responds with the error name and message when no stack trace is lazily generated.', async(): Promise<void> => {
+    const error = new Error('error');
+    error.stack = undefined;
+    await writer.handle({ response, result: error });
+    expect(response._isEndCalled()).toBeTruthy();
+    expect(response._getStatusCode()).toBe(500);
+    expect(response._getData()).toMatch('Error: error');
+  });
+
+  it('ends its response with a newline if there is an error.', async(): Promise<void> => {
+    await writer.handle({ response, result: new Error('error') });
+    expect(response._isEndCalled()).toBeTruthy();
+    expect(response._getData().endsWith('\n')).toBeTruthy();
+  });
 });