package wand

import (
	"bytes"
	"fmt"
	"strings"
	"testing"
)

func testExec(impl any, env, commandLine, err string, expect ...string) func(*testing.T) {
	return func(t *testing.T) {
		var exitCode int
		exit := func(code int) { exitCode = code }
		stdout := bytes.NewBuffer(nil)
		stderr := bytes.NewBuffer(nil)
		cmd := wrap(impl)
		e := strings.Split(env, ";")
		a := strings.Split(commandLine, " ")
		exec(stdout, stderr, exit, cmd, e, a)
		if exitCode != 0 && err == "" {
			t.Fatal("non-zero exit code:", stderr.String())
		}

		if err != "" && exitCode == 0 {
			t.Fatal("failed to fail")
		}

		if err != "" && !strings.Contains(stderr.String(), err) {
			t.Fatal("expected error not received:", stderr.String())
		}

		if exitCode != 0 {
			return
		}

		var expstr []string
		for _, e := range expect {
			expstr = append(expstr, fmt.Sprint(e))
		}

		if stdout.String() != strings.Join(expstr, "\n")+"\n" {
			t.Fatal("unexpected output:", stdout.String())
		}
	}
}