forgejo/modules/util/truncate_test.go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package util

import (
	"testing"

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

func TestSplitString(t *testing.T) {
	type testCase struct {
		input    string
		n        int
		leftSub  string
		ellipsis string
	}

	test := func(tc []*testCase, f func(input string, n int) (left, right string)) {
		for _, c := range tc {
			l, r := f(c.input, c.n)
			if c.ellipsis != "" {
				assert.Equal(t, c.leftSub+c.ellipsis, l, "test split %q at %d, expected leftSub: %q", c.input, c.n, c.leftSub)
				assert.Equal(t, c.ellipsis+c.input[len(c.leftSub):], r, "test split %s at %d, expected rightSub: %q", c.input, c.n, c.input[len(c.leftSub):])
			} else {
				assert.Equal(t, c.leftSub, l, "test split %q at %d, expected leftSub: %q", c.input, c.n, c.leftSub)
				assert.Empty(t, r, "test split %q at %d, expected rightSub: %q", c.input, c.n, "")
			}
		}
	}

	tc := []*testCase{
		{"abc123xyz", 0, "", utf8Ellipsis},
		{"abc123xyz", 1, "", utf8Ellipsis},
		{"abc123xyz", 4, "a", utf8Ellipsis},
		{"啊bc123xyz", 4, "", utf8Ellipsis},
		{"啊bc123xyz", 6, "啊", utf8Ellipsis},
		{"啊bc", 5, "啊bc", ""},
		{"啊bc", 6, "啊bc", ""},
		{"abc\xef\x03\xfe", 3, "", asciiEllipsis},
		{"abc\xef\x03\xfe", 4, "a", asciiEllipsis},
		{"\xef\x03", 1, "\xef\x03", ""},
	}
	test(tc, SplitStringAtByteN)
}

func TestTruncateRunes(t *testing.T) {
	assert.Empty(t, TruncateRunes("", 0))
	assert.Empty(t, TruncateRunes("", 1))

	assert.Empty(t, TruncateRunes("ab", 0))
	assert.Equal(t, "a", TruncateRunes("ab", 1))
	assert.Equal(t, "ab", TruncateRunes("ab", 2))
	assert.Equal(t, "ab", TruncateRunes("ab", 3))

	assert.Empty(t, TruncateRunes("测试", 0))
	assert.Equal(t, "测", TruncateRunes("测试", 1))
	assert.Equal(t, "测试", TruncateRunes("测试", 2))
	assert.Equal(t, "测试", TruncateRunes("测试", 3))
}