//nolint:testpackage // white-box tests exercise unexported internals
package mfer

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// TestValidatePathMessagesVerbatim pins the exact rendered text of every
// ValidatePath rejection.
//
// These strings are user-visible and are assembled by wrapping static
// sentinels mid-sentence, which makes them easy to reword by accident
// while refactoring for errors.Is matchability. Changing one is a
// deliberate change, not a refactoring side effect.
func TestValidatePathMessagesVerbatim(t *testing.T) {
	t.Parallel()

	for _, tc := range []struct {
		name string
		path string
		want string
		is   error
	}{
		{
			name: "empty",
			path: "",
			want: "path cannot be empty",
			is:   errPathEmpty,
		},
		{
			name: "not utf8",
			path: "a\xffb",
			want: `path "a\xffb" is not valid UTF-8`,
			is:   errPathNotUTF8,
		},
		{
			name: "backslash",
			path: `a\b`,
			want: `path "a\\b" contains backslash; ` +
				"use forward slashes only",
			is: errPathBackslash,
		},
		{
			name: "absolute",
			path: "/a/b",
			want: `path "/a/b" is absolute; must be relative`,
			is:   errPathAbsolute,
		},
		{
			name: "empty segment",
			path: "a//b",
			want: `path "a//b" contains empty segment`,
			is:   errPathEmptySegment,
		},
		{
			name: "dotdot segment",
			path: "a/../b",
			want: `path "a/../b" contains '..' segment`,
			is:   errPathDotDot,
		},
	} {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()

			err := ValidatePath(tc.path)
			require.Error(t, err)
			assert.Equal(t, tc.want, err.Error())
			require.ErrorIs(t, err, tc.is)
		})
	}
}

// TestSerializeInternalErrorMessagesVerbatim pins the two distinct
// "internal error" messages, which differ between generate and
// generateOuter and have always done so.
func TestSerializeInternalErrorMessagesVerbatim(t *testing.T) {
	t.Parallel()

	m := &manifest{}
	require.EqualError(t, m.generate(), "internal error: pbInner not set")
	require.EqualError(t, m.generateOuter(), "internal error")
}