Testing

This guide covers testing a Tinka App. You will learn how to:

Run the App's tests with act test
Run some of the tests, with go test's flags
Run only the tests that failed last time
Run the tests on every change
Read the results as an agent

Overview

A Tinka App's tests are Go tests: functions named TestXxx in _test.go files, using the standard library's testing package, run by go test. Nothing about them is specific to Tinka, so every editor, coverage tool and CI system that knows Go runs them.

act test runs go test for you, with the same flags and the same cache. It tests the whole App by default, prints failures the way go test does, remembers which tests failed so you can run only them again, and runs the tests again on every change. It prints the go test command it runs first, so you can always run the same thing without it.

Run the tests

Run act test from the App's directory:

Terminal

act test

Output

$ GOWORK=off go test -json ./...
--- FAIL: TestTitle (0.00s)
    --- FAIL: TestTitle/empty (0.00s)
        posts_test.go:8: an empty title was accepted
FAIL
FAIL	example.com/blog/posts	0.005s
ok  	example.com/blog/users	0.004s
Error: 1 test failed.
  Fix: Run act test --failed to run only them again

act test runs go test with -json and prints what go test prints without it, so it can read the results as they come. A package whose code and tests haven't changed since its last passing run comes from go test's cache, marked (cached), and takes no time.

Running the tests runs the App's code, so the first time, act asks whether you trust the App's directory. See act trust.

Run some of the tests

Flags and packages after act test go to go test, as they are. Without packages, act test tests the whole App:

Terminal

act test -run TestPublish ./posts
act test -v -count=1 ./...

-run selects tests by name, -v prints every test's output, and -count=1 runs tests whose results are cached. See go help testflag for the rest.

Run failed tests again

act test remembers the tests that failed. --failed runs only them, in the packages they failed in:

Terminal

act test --failed

Once they pass, act test --failed has nothing left to run, and says so.

Run the tests on every change

--watch runs the tests, then again each time a Go file, a test or a file under testdata changes, until you press Ctrl+C:

Terminal

act test --watch

go test's cache makes each run cost only the packages your change affects.

Read results as an agent

When an agent runs act test, or with --json, it prints one JSON result: how many tests passed, failed and were skipped, in how many packages, and how many came from the cache. A failed run fails with the code tests_failed, or build_failed when a package doesn't compile, and carries the same counts in error.details, with each failed test and the last lines it printed:

Output

{"command":"test","result":"error","error":{"code":"tests_failed","message":"1 test failed","fix":"Run act test --failed to run only them again","details":{"passed":1,"failed":2,"skipped":0,"packages":1,"cached":0,"failures":[{"package":"example.com/blog/posts","test":"TestTitle/empty","output":"--- FAIL: TestTitle/empty (0.00s)\n    posts_test.go:8: an empty title was accepted\n"}],"go_command":"GOWORK=off go test -json ./..."}},"log":"/tmp/act-2741.log","tail":"--- FAIL: TestTitle (0.00s)\n    --- FAIL: TestTitle/empty (0.00s)\n        posts_test.go:8: an empty title was accepted\nFAIL\nFAIL\texample.com/blog/posts\t0.005s","duration_ms":319}

failed counts a failing subtest and its parent, while failures lists only the subtest, since it says what went wrong.