Do you use tests for external (rest) apis you rely on? And what do you test if you do?

<p>I am building some package that relies, at least for some functionality, on an external api which is not mine, and as such might change or stop working at any moment. </p> <p>To isolate the api code for this external service as much as possible from the rest from my code I put all this code in a sub package that satisfies an interface I declared in the root of my package to access it.</p> <p>Then I declare some tests in that sub package that do some calls of which I know what the output should be and compare that with what it should be. This way any changes to the api that I am not aware of might be caught.</p> <p>Is it idiomatic to use tests like this? It seems a bit weird since your tests can fail now because your internet connection might be down or the request times out for some other reason.</p> <hr/>**评论：**<br/><br/>DenzelM: <pre><p>Some people refer to what you&#39;re talking about as broad integration tests or system tests. These are completely normal. They&#39;ll help you catch the exact issue you&#39;re worried about: &#34;changes to the API you&#39;re not aware of&#34;.</p> <p>With that said, you&#39;ll want to use <a href="https://stackoverflow.com/questions/25965584/separating-unit-tests-and-integration-tests-in-go" rel="nofollow">build tags</a> to separate your deterministic tests from your nondeterministic ones.</p></pre>diabetesjones: <pre><p>Good question, I think there are a lot of different approaches. I make dummy API accounts, get the secrets from environment variables, and put the API calls right into my tests. I assume I will have an internet connection - I need this for so much else in my workflow that this is a safe assumption. Then I can make API calls on this dummy account without screwing up my real dev/staging/prod API creds. Just <code>export</code> your necessary env vars before tests. </p> <p>Like this:<br/> <a href="https://github.com/etherparty/coinpayments/blob/develop/client_test.go" rel="nofollow">https://github.com/etherparty/coinpayments/blob/develop/client_test.go</a><br/> Then a test using that client:<br/> <a href="https://github.com/etherparty/coinpayments/blob/develop/tx_test.go" rel="nofollow">https://github.com/etherparty/coinpayments/blob/develop/tx_test.go</a></p></pre>