get getResourceAsStream的单元测试

Question

I have a controller with

InputStream inStream = ControllerClass.getClass().getResourceAsStream(doc); 

doc is a stream that I send in via httpservletrequest (it will be /doc/xxx.json). If I want to unit test this controller, I have to create a mock resource first for the code above to fetch my mock resource. As I know, the above code will fetch the file from the path project/target/classes/doc/xxx.json .

How can you create a mock file at the path in order to unit test the controller?

Answer 1

You don't need to create a mock file in order to unit test the controller until and unless its a very huge JSON String.

Just try with this simple code:

InputStream inStream = new StringInputStream(mockJsonString);

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As per your last comment - won't find the file at /doc/xxx.json

Try this one

InputStream inStream = new FileInputStream(new File("doc/xxx.json"));

Answer 2

I just went through the hell of how resourceasstream can behave differently under different circumstances. I ended up changing over to basically mocking the source and the mock really just returned the JSON or HTML we wanted to use in the tests in question.

Can't recommend this enough. The code is cleaner and you are not trying to figure out whether a file ended up in the classpath or where off the classpath it is. If your file is large, it might be less appealing, but you could even create modular versions of those assembled files, eg:

new MockResponse.Builder().addHeader(headerJSON).body(forecastTable).build();

Of course, those elements will be strings somewhere, but you could do a lot of organizing that frankly your sample test files don't have.

I rethought this because I spent a bunch of time looking at tests that ran under gradle at the command line but not inside IntelliJ. But then I was thinking about how Karma works in Angular: when you are writing tests against expected responses, you are literally saying things like:

.when("/forecasts").respond("{ forecasts: [ { "mon", 75º }, { "tue", "78º" } ... ]")

So the idea that responses would be mocked as literal snippets is deemed acceptable there.