fix(adapter): Clone the recording entry before mutating it (#294)

Clone the recording entry before the `beforeReplay` event so any changes will not actually persist to the stored recording.
Netflix · Jan 13, 2020 · d7e1303 · d7e1303
1 parent 5fe991d
commit d7e1303
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Showing 2 changed files with 56 additions and 5 deletions.
diff --git a/packages/@pollyjs/adapter/src/index.js b/packages/@pollyjs/adapter/src/index.js
@@ -156,9 +156,18 @@ export default class Adapter {
     const recordingEntry = await this.persister.findEntry(pollyRequest);
 
     if (recordingEntry) {
-      await pollyRequest._emit('beforeReplay', recordingEntry);
+      /*
+        Clone the recording entry so any changes will not actually persist to
+        the stored recording.
 
-      if (isExpired(recordingEntry.startedDateTime, config.expiresIn)) {
+        Note: Using JSON.parse/stringify instead of lodash/cloneDeep since
+              the recording entry is stored as json.
+      */
+      const clonedRecordingEntry = JSON.parse(JSON.stringify(recordingEntry));
+
+      await pollyRequest._emit('beforeReplay', clonedRecordingEntry);
+
+      if (isExpired(clonedRecordingEntry.startedDateTime, config.expiresIn)) {
         const message =
           'Recording for the following request has expired.\n' +
           `${stringifyRequest(pollyRequest, null, 2)}`;
@@ -184,13 +193,13 @@ export default class Adapter {
         }
       }
 
-      await this.timeout(pollyRequest, recordingEntry);
+      await this.timeout(pollyRequest, clonedRecordingEntry);
       pollyRequest.action = ACTIONS.REPLAY;
 
       return this.onReplay(
         pollyRequest,
-        normalizeRecordedResponse(recordingEntry.response),
-        recordingEntry
+        normalizeRecordedResponse(clonedRecordingEntry.response),
+        clonedRecordingEntry
       );
     }
 

diff --git a/tests/integration/adapter-tests.js b/tests/integration/adapter-tests.js
@@ -1,3 +1,4 @@
+import { Polly } from '@pollyjs/core';
 import { ACTIONS } from '@pollyjs/utils';
 
 export default function adapterTests() {
@@ -126,6 +127,47 @@ export default function adapterTests() {
     ]);
   });
 
+  it('should call beforeReplay with a cloned recording entry', async function() {
+    const { recordingId, recordingName, config } = this.polly;
+    let replayedEntry;
+
+    this.polly.record();
+    await this.fetchRecord();
+    await this.polly.stop();
+
+    this.polly = new Polly(recordingName, config);
+    this.polly.replay();
+
+    const har = await this.polly.persister.find(recordingId);
+
+    expect(har).to.be.an('object');
+    expect(har.log.entries).to.have.lengthOf(1);
+
+    this.polly.server
+      .get(this.recordUrl())
+      .on('beforeReplay', (_req, entry) => (replayedEntry = entry));
+
+    const entry = har.log.entries[0];
+
+    await this.fetchRecord();
+
+    expect(replayedEntry).to.be.an('object');
+
+    expect(entry).to.deep.equal(replayedEntry);
+    expect(entry).to.not.equal(replayedEntry);
+
+    expect(entry.request).to.deep.equal(replayedEntry.request);
+    expect(entry.request).to.not.equal(replayedEntry.request);
+
+    expect(entry.response).to.deep.equal(replayedEntry.response);
+    expect(entry.response).to.not.equal(replayedEntry.response);
+
+    expect(entry.response.content).to.deep.equal(
+      replayedEntry.response.content
+    );
+    expect(entry.response.content).to.not.equal(replayedEntry.response.content);
+  });
+
   it('should emit an error event', async function() {
     const { server } = this.polly;
     let error;