Simple pFlag go test

main.go

package main

import (
	"flag"
	"fmt"

	"github.com/spf13/pflag"
)

var (
	argPort = pflag.Int("port", 8443, "The secure port to listen to for incoming HTTPS requests.")
)

func main() {
	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
	pflag.Parse()
	fmt.Printf("We got port: %d", *argPort)

}

main_test.go

package main

import (
	"testing"

	"github.com/spf13/pflag"
	"gotest.tools/assert"
	is "gotest.tools/assert/cmp"
)

func TestCliFlags(t *testing.T) {
	flags := pflag.NewFlagSet("testing", pflag.ContinueOnError)
	err := flags.Parse([]string{
		"--port=8080",
	})
	assert.Check(t, err)
	assert.Check(t, is.Equal(8080, *argPort))

}

Output of test:

$ go test
--- FAIL: TestCliFlags (0.00s)
	main_test.go:16: assertion failed: error is not nil: unknown flag: --port
	main_test.go:17: assertion failed: 8080 (int) != 8443 (argPort int)
FAIL
exit status 1
FAIL	github.com/frenchben/cliex	0.008s