A variadic function accepts an arbitrary number of values of the same type. With `func testRun(args ...string)`, callers provide separate strings, while the function receives `args` as a `[]string`. section 5.4.3 section 5.6
A convenient CLI test helper
A test helper can accept command-line arguments directly: `testRun("-c=2", "-n=1")`. Inside the helper, prepend the program name with `append([]string{"hit"}, args...)`, producing the argument list expected by the command runner. This keeps tests concise while returning the test environment and any execution error. section 5.4.3 section 5.4
Use either of these call forms:
- Pass values individually: `testRun("-c=2", "-n=1", "https://github.com/inancgumus")`. section 5.4.3
- Expand an existing slice with `...`: `testRun([]string{"-c=2", "-n=1"}...)`. section 5.4.3
- Copy a slice before expansion when the helper might modify its elements: `testRun(append([]string{}, args...)...)`. section 5.4.3
Listing 5.6 Test runner helper (hit/cmd/hit_test.go)
func testRun(args ...string) (*testEnv, error) { #1
var tenv testEnv #2
err := run(&env{ #3
args: append([]string{"hit"}, args...), #4
stdout: &tenv.stdout, #5
stderr: &tenv.stderr, #5
dryRun: true, #6
})
return &tenv, err #7
}
Inspect the complete test runner helper, including variadic declaration, argument construction, dry-run configuration, and returned results. section 5.4.3
