package validate

import (
	"errors"
	"fmt"
	"testing"
)

func ExampleCollect() {
	v := Collect(MinLength(4), Chars("0123456789abcdef"))
	fmt.Println(v("xy"))
	// Output:
	// must contain at least 4 characters
	// contains disallowed characters
}

func TestCollect(t *testing.T) {
	v := Collect(
		MinLength(4),
		MaxLength(8),
		Chars("0123456789abcdef"),
	)

	t.Run("no failures returns nil", func(t *testing.T) {
		if err := v("abc123"); err != nil {
			t.Fatalf("got %v, want nil", err)
		}
	})

	t.Run("every failure is reported", func(t *testing.T) {
		// too long (>8) and contains disallowed characters; not too short.
		err := v("xyz!!!!!!!!")

		if errors.Is(err, ErrMustBeLonger) {
			t.Error("did not expect ErrMustBeLonger in", err)
		}
		if !errors.Is(err, ErrMustBeShorter) {
			t.Error("want ErrMustBeShorter in", err)
		}
		if !errors.Is(err, ErrDisallowedChars) {
			t.Error("want ErrDisallowedChars in", err)
		}
	})

	t.Run("a single failure still matches with errors.Is", func(t *testing.T) {
		err := v("12") // only too short

		if !errors.Is(err, ErrMustBeLonger) {
			t.Error("want ErrMustBeLonger in", err)
		}
		if errors.Is(err, ErrDisallowedChars) {
			t.Error("did not expect ErrDisallowedChars in", err)
		}
	})
}