Is it possible to mock a function imported from a package in golang?

by

Yes, with a simple refactoring. Create a zSomeFunc variable of function type, initialized with z.SomeFunc, and have your package call that instead of z.SomeFunc():

var zSomeFunc = z.SomeFunc

func abc() {
    // ...
    v := zSomeFunc()
    // ...
}

In tests you may assign another function to zSomeFunc, one that is defined in tests, and does whatever the test wants it to.

For example:

func TestAbc(t *testing.T) {
    // Save current function and restore at the end:
    old := zSomeFunc
    defer func() { zSomeFunc = old }()

    zSomeFunc = func() int {
        // This will be called, do whatever you want to,
        // return whatever you want to
        return 1
    }

    // Call the tested function
    abc()

    // Check expected behavior
}

See related / possible duplicate:
Testing os.Exit scenarios in Go with coverage information (coveralls.io/Goveralls)

More Related Contents:

  1. Is it possible to mock a function imported from a package?
  2. Mock functions in Go
  3. Fill os.Stdin for function that reads from it
  4. Testing os.Exit scenarios in Go with coverage information (coveralls.io/Goveralls)
  5. How to mock specific methods but not all of them in Rust?
  6. What is Mocking?
  7. What’s the difference between faking, mocking, and stubbing?
  8. When should I mock?
  9. Final method mocking
  10. How to run only one unit test class using Gradle
  11. What is the purpose of mock objects?
  12. What are the differences between unit tests, integration tests, smoke tests, and regression tests? [closed]
  13. Random data in Unit Tests?
  14. Mocking vs. Spying in mocking frameworks
  15. Is UnitOfWork and GenericRepository Pattern redundant In EF 4.1 code first?
  16. How to test my servlet using JUnit
  17. How does mockito when() invocation work?
  18. How can one mock/stub python module like urllib
  19. Updating input html field from within an Angular 2 test
  20. Mock attributes in Python mock?
  21. How do you mock a Sealed class?
  22. What is the best way to unit-test SLF4J log messages?
  23. How to unit test a Go Gin handler function?
  24. Is there an easy way to stub out time.Now() globally during test?
  25. How to test or mock “if __name__ == ‘__main__'” contents
  26. Unit testing a method that calls another method
  27. Proper package naming for testing with the Go language
  28. What is a “Stub”?
  29. Unit testing a python app that uses the requests library
  30. Example code for testing the filesystem in Golang

Leave a Comment