Mock string resource in Android unit testing using Robolectric 3 - java

I've read a couple of answers online but none of them seem to work for me.
This is what I have in my #Setup method:
MockitoAnnotations.initMocks(this);
Configuration mConfiguration = Mockito.mock(Configuration.class);
mConfiguration.locale = Locale.US;
when(mContext.getResources().getConfiguration()).thenReturn(mConfiguration);
when(StorageUtils.getUserAgent(mContext)).thenReturn("User-Agent: Android Unit Test");
when(mContext.getResources().getString(R.string.service_domain)).thenReturn("testString");
All of it works, except the last line getString. Ideally the string would be from the actual strings resource I already have for the whole app, but if that's not possible, I can add it to this line manually.
The part that doesn't work is when I try to call the string.
The .getString(R.string.service_domain) part is getting called in another method (the method used in the actual application) as part of the context.
So my method is called like this from unit test:
Utils.getProductImageUrl(mContext, product);
And this getProductImageUrl does this:
productImageUrl = context.getString(R.string.service_domain) + baseImageUrl;
When I run the unit test, the productImageUrl variable get a full url of
null/123.png
How can I mock the string so it can be passed as part of the context to my method?
Let me know if you need additional information.
Thank you.

Related

Write a Unit Test to check the variable which is not getting returned by the method

Below is the codeSnippet of what i have to test:
the builder value is getting set but it is not being returned.
Please suggest me a way to test the below method.
public String convertMarkup(request)
{
Builder builder = new Response.builder();
String markUpData;
Map<String,List<String>>collectUrls= collectUrlMethod(request);
if(MapUtils.isNotEmpty(collectUrls)){
builder.setTrackerValue(collectUrls.get(Final_value).get(0));
builder.build();
}else{
markUpData="abc";
// rest of the code
}
return markUpData;
}
Tried changing the code around by introducing a new variable in input request and setting that variable instead of using a new builder. That worked.
public String convertMarkup(requestContext) {
Builder builder = new Response.builder();
String markUpData;
Map<String,List<String>>collectUrls= collectUrlMethod(request);
if(MapUtils.isNotEmpty(collectUrls)){
requestContext.setTrackerValue(collectUrls.get(Final_value).get(0));
}else{
markUpData="abc";
// rest of the code
}
return markUpData; }
builder isn't actually used, unless there's some side effect of calling builder.build(), which would be poor design, so you don't have to test it, and in fact you shouldn't test it.
The "unit" you are testing is the convertMarkup() method, which you test by giving it input and asserting its output - nothing more. Anything inside the method is implementation choice, and is free to be changed at any time, so your unit tests should not depend on it.
For example, a developer may change the implementation to:
public String convertMarkup(requestContext) {
return someExternalService.convertMarkup(requestContext);
}
after which all your tests should still compile and pass (assuming the external service works properly, of course).
Code coverage is another matter. Projects should set a minimum code coverage ratio and that may require more unit tests to exercise sufficient code paths, but they are likely valid unit test edges cases anyway.

JUnit - How to unit test method that reads files in a directory and uses external libraries

I have this method that I am using in a NetBeans plugin:
public static SourceCodeFile getCurrentlyOpenedFile() {
MainProjectManager mainProjectManager = new MainProjectManager();
Project openedProject = mainProjectManager.getMainProject();
/* Get Java file currently displaying in the IDE if there is an opened project */
if (openedProject != null) {
TopComponent activeTC = TopComponent.getRegistry().getActivated();
DataObject dataLookup = activeTC.getLookup().lookup(DataObject.class);
File file = FileUtil.toFile(dataLookup.getPrimaryFile()); // Currently opened file
// Check if the opened file is a Java file
if (FilenameUtils.getExtension(file.getAbsoluteFile().getAbsolutePath()).equalsIgnoreCase("java")) {
return new SourceCodeFile(file);
} else {
return null;
}
} else {
return null;
}
}
Basically, using NetBeans API, it detects the file currently opened by the user in the IDE. Then, it loads it and creates a SourceCodeFile object out of it.
Now I want to unit test this method using JUnit. The problem is that I don't know how to test it.
Since it doesn't receive any argument as parameter, I can't test how it behaves given wrong arguments. I also thought about trying to manipulate openedProject in order to test the method behaviour given some different values to that object, but as far as I'm concernet, I can't manipulate a variable in JUnit that way. I also cannot check what the method returns, because the unit test will always return null, since it doesn't detect any opened file in NetBeans.
So, my question is: how can I approach the unit testing of this method?
Well, your method does take parameters, "between the lines":
MainProjectManager mainProjectManager = new MainProjectManager();
Project openedProject = mainProjectManager.getMainProject();
basically fetches the object to work on.
So the first step would be to change that method signature, to:
public static SourceCodeFile getCurrentlyOpenedFile(Project project) {
...
Of course, that object isn't used, except for that null check. So the next level would be to have a distinct method like
SourceCodeFile lookup(DataObject dataLookup) {
In other words: your real problem is that you wrote hard-to-test code. The "default" answer is: you have to change your production code, to make easier to test.
For example by ripping it apart, and putting all the different aspects into smaller helper methods.
You see, that last method lookup(), that one takes a parameter, and now it becomes (somehow) possible to think up test cases for this. Probably you will have to use a mocking framework such as Mockito to pass mocked instances of that DataObject class within your test code.
Long story short: there are no detours here. You can't test your code (in reasonable ways) as it is currently structured. Re-structure your production code, then all your ideas about "when I pass X, then Y should happen" can work out.
Disclaimer: yes, theoretically, you could test the above code, by heavily relying on frameworks like PowerMock(ito) or JMockit. These frameworks allow you to contol (mock) calls to static methods, or to new(). So they would give you full control over everything in your method. But that would basically force your tests to know everything that is going on in the method under test. Which is a really bad thing.

Should I repeat code in actual class in tests

I want to test that a specific method produces the expected result, but to do that I need to manipulate the input in the test as well.
class ToTest {
public String produceResponse(String input) {
// ....
encryptedIds = encryptIds(input)
output = doStuff(input, encryptedIds)
}
public encryptIds(input) {
....
}
}
In my test I need to check that produceResponse actually produces the expected response.
in order to do that I have to encrypt the ids in the input.
My question is: should I rewrite encryptIds in the test (so that I would have more controller on the result) or should I call encryptIds from the class itself.
Is there a better approach to solve this? I don't like that in my test I know what happens in the specific flow.
If I understand correctly, you would like to test produceResponse() with known encryptedIds as input.
You could do that without refactoring the code, but it would probably be a good idea to refactor it, so that's what I'm going to explain:
class ToTest {
private IdEncryptor encryptor;
public ToTest(IdEncryptor encryptor) {
this.encryptor = encryptor;
}
public String produceResponse(String input) {
String[] encryptedIds = encryptor.encryptIds(input);
return doStuff(input, encryptedIds);
}
}
Now you can unit-test IdEncryptor to test that it produces correct encrypted IDs based on a String input.
And to test the ToTest class, you can mock the IdEncryptor so that whatever the input it receives, it produces the encryptedIds you desire. For example with mockito:
IdEncryptor mockEncryptor = mock(IdEncryptor.class);
when(mockEncryptor.encryptIds(any(String.class)).thenReturn(new String[] {"a", "b"});
ToTest toTest = new ToTest(mockEncryptor);
String response = toTest.produceResponse("input");
// expect that the response is what you expect given "a", "b" as input of doStuff()
Never copy any production code into the unit test as it will get outdated at some point.
If both methods are public, they are part of the public API, so:
you should first unit test the correct behavior of the encryptIds(String) method
then unit test the produceResponse(String) method which will internally use the already tested encryptIds(String) method
If encryptIds(String) would not be part of the public API:
then it is internal implementation and helper method which is not unit testable
produceResponse(String) is then responsible for encryption as a side-effect:
you can still test it if you mark it package private (no modifier)
you can also change the implementation of the encryptIds(String) only for testing purposes
Is encrypting id's something that is integral to your system or not? As it stands this class takes some input and produces some output and as far as your test is concerned this is what's important, no more, no less.
What is the impact of not performing the encryption? If your doStuff method will just fail if it doesn't happen then it is an internal detail to your class-under-test and I wouldn't have the tests care about it at all. If it's a step that absolutely must be performed then I would refactor the code to verify that it absolutely has happened, maybe using a mock as #jb-nizet answered.
As for the general case of duplicating production code in tests, as #Crazyjavahacking stated you should not do this, but I have no issue with using production code from a test- maybe not at a unit level but definitely the higher up the system I go, e.g. when testing writing to a DB I will use the reading code to verify it's happened correctly, but will also have independent tests to verify the reading path as well

JUnit | How to pass parameters returned from one Junit test into another JUnit test

I have a junit test testArchive(). The Junit test tests the archive() method that archives a file and returns the url to it as a String. The URL is defined as an instance variable inside the Junit Test class.
class Prepare {
private String url = "";
#Test
public void testArchive() {
String url = getService().archive();
}
#Test
public void testSendEmail() {
getService().sendEmail(url) // Url is turning out to be null
}
} // end of class
I am writing another Junit test for sendEmail() which emails the URL. But the URL is turning out to be null, though its defined as a class variable
Can you please let me know how I need to correct my Junit test for send email?
Thank you
Short answer:
You should really not do that.
Detailed answer:
Unit tests (and therefore JUnit tests as well) are intended to run separately and independently from each other. Each test should check only one method, regardless of result of another method or another test. So in your case, method testSendEmail() should use some hard coded URL, or better few different URLs.
Keep in mind that:
Test cases should not have side effects: the .archive() looks like will produce side effects
Test cases should not assume an execution order of other test cases: your testSendEmail seems to assume testArchive is executed first, which is wrong
Test cases should not depend on external factors: the getService calls looks like an external (uncontrolled) factor
Test cases should be independent and self-contained
Instead of one test cases depending on the outcome of another,
you could use a private helper method that both test cases can call.
I removed the 2nd JUnit test and consolidated the tests into 1. Both archive and email will happen in one test.

Tests granularity when using mock object

I have Struts 1 action and want to test it in isolation.
What this action do is as follows:
load data using parameters from request
build xml-based representation of this data
send this response directly to client
I use jMock for testing but have one doubt here.
My first test is
public void shouldActionInvocationPrintValidResponse() {
ProcessingAction action = new ProcessingAction();
DBService service = mock(DBService.class);
List records = new ArrayList();
when(service.loadData()).thenReturn(records);
ResponseBuilder builder = mock(ResponseBuilder.class);
when(builder.buildResponse(records)).thenReturn("fake response");
action.execute(null, null, null, null);
assertEquals("fake response", writer.getContentWritten());
}
And my prod code evaluated to this:
public String execute(...) {
List recordsList = service.loadData();
String response = responseBuilder.buildResponse(recordsList);
response.getWriter().print(response);
}
My doubt here is if such test isn't too big here. I check whole succesful flow here. Shouldn't there be separate tests for checking every single dependency call in their own tests?
I wonder because I had troubles with this test's name. My ideas at the beginning were something like
shouldFetchDataThenFormatThemAndSendResponse
As this is all the tests does, the name shows it probably does too much (look at the "and" e.g. in the test name)
And should I have whole test written at once, or just add dependencies calls step-by-step?
EDIT:
Detailed code for test and action provided.
I think you are on the right track. shouldFetchDataThenFormatThemAndSendResponse This says it all. In your test naming you are talking about implementation details. This is how your first test should have been written.
ProcessingAction action = new ProcessingAction();
Response response = action.execute();
assertEquals(true, response.IsValid);
Try: shouldGetResponseWhenActionExecuted.
Now you can look at how to get a response when executing an action.
I would bet you dollars to donuts that you didn't TDD this.
Remember: Intent over Implementation! Stop showing your crusty underwear.
It is hard to answer your question without seeing the code however I will give it a stab. For the test to be a Unit test, it should not exercise code other than the code in the class under test. If you have mocked every other class that the action calls and what you are verifying is only being done within the class under test, then no the test is not too big. I have written unit tests that have a large number of verification statements because all the things happen in the class under test due to the single invocation of the method.
My unit test rules are:
1. Exercise code only in the class under test
2. Only enter the method under test once per test method
I agree with John B.
Also, if you use the Mock Test Runner and write it correctly, you may not need an assertion.

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