Fix existing GCS tests to match others.

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

packages/techdocs-common/__mocks__/@google-cloud/storage.ts

@@ -63,6 +63,9 @@ class GCSFile {
 
     process.nextTick(() => {
       if (fs.existsSync(this.localFilePath)) {
+        if (readable.eventNames().includes('pipe')) {
+          readable.emit('pipe');
+        }
         readable.emit('data', fs.readFileSync(this.localFilePath));
         readable.emit('end');
       } else {

packages/techdocs-common/src/stages/publish/googleStorage.test.ts

@@ -309,7 +309,9 @@ describe('GoogleGCSPublish', () => {
       const pngResponse = await request(app).get(
         `/${namespace}/${kind}/${name}/img/with%20spaces.png`,
       );
-      expect(pngResponse.text).toEqual('found it');
+      expect(Buffer.from(pngResponse.body).toString('utf8')).toEqual(
+        'found it',
+      );
       const jsResponse = await request(app).get(
         `/${namespace}/${kind}/${name}/some%20folder/also%20with%20spaces.js`,
       );