Using Interfaces to Automate Tests
Explore how to automate output testing in Go by leveraging the io.Writer interface. Understand updating functions to accept interfaces, capturing printed output using bytes.Buffer, and improving test automation for command-line tools. This lesson guides you through practical steps to increase test flexibility and robustness.
Sometimes we need a way to test output printed out to STDOUT. In this
instance, when executing the integration tests, by testing the run() function,
the name of the output file is created dynamically. The function prints this
value to the screen so the user can use the file, but to automate tests, we
need to capture this output from within the test case.
Include the io package
In Go, the idiomatic way to deal with this situation is by using interfaces, in
this case io.Writer, to make code more flexible. For this pattern, we update
the function run() so that it takes the interface as an input parameter. We do
this so we can call ...