[Tables] Batch integration test fail when run in playback mode against browser

[joheredi]

batch operations tests fail when run in playback mode against browse, they work fine when run in live mode. Tests targeting node work with any test mode.

Error: Refused to set unsafe header "accept-charset"
          at FakeXMLHttpRequest.setRequestHeader (dist-test/integration.index.browser.js:25423:27 <- dist-test/integration.index.browser.js:8866:938)
          at XhrHttpClient.sendRequest (dist-test/integration.index.browser.js:3512:21 <- dist-test/integration.index.browser.js:668:531)
          at LogPolicy.sendRequest (dist-test/integration.index.browser.js:4084:41 <- dist-test/integration.index.browser.js:782:485)
          at DeserializationPolicy.<anonymous> (dist-test/integration.index.browser.js:4334:30 <- dist-test/integration.index.browser.js:804:1344)
          at step (dist-test/integration.index.browser.js:118:27 <- dist-test/integration.index.browser.js:15:9800)
          at Object.next (dist-test/integration.index.browser.js:99:57 <- dist-test/integration.index.browser.js:15:6649)
          at dist-test/integration.index.browser.js:92:75 <- dist-test/integration.index.browser.js:15:5887
          at new Promise (<anonymous>)
          at __awaiter (dist-test/integration.index.browser.js:88:16 <- dist-test/integration.index.browser.js:15:5042)
          at DeserializationPolicy.sendRequest (dist-test/integration.index.browser.js:4330:20 <- dist-test/integration.index.browser.js:804:1081)

@sadasant have you ever seen something like this?

[sadasant]

@joheredi We need more information.

• Turn on the logs and see if you can find the HTTP request that sets that header. Do this your favorite way. We need to see both the request and the response, if possible. If we obtain a response, and we see the error in the response, this changes drastically how we will approach this problem.
• I can imagine this either being a Karma problem, or a bug in the recorder.
• I need to confirm, using TEST_MODE=live AND running the browser tests pass without this error? This would mean the issue is most likely in the recorder and not in Karma.
• We would need to go deeper in the recorder and see if we can spot the problem. Ping me when you can and let's have a call.

[joheredi]

Turns out that some headers seem to be marked as "unsafe". I'm fixing this by only adding those headers if running in node

[jeremymeng]

Related sinonjs/nise#177