Merge pull request #6149 from bep/sort-caseinsensitive

Implement lexicographically string sorting

compare/compare_strings_test.go

@@ -0,0 +1,66 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package compare
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCompare(t *testing.T) {
+	assert := require.New(t)
+	for i, test := range []struct {
+		a string
+		b string
+	}{
+		{"a", "a"},
+		{"A", "a"},
+		{"Ab", "Ac"},
+		{"az", "Za"},
+		{"C", "D"},
+		{"B", "a"},
+		{"C", ""},
+		{"", ""},
+		{"αβδC", "ΑΒΔD"},
+		{"αβδC", "ΑΒΔ"},
+		{"αβδ", "ΑΒΔD"},
+		{"αβδ", "ΑΒΔ"},
+		{"β", "δ"},
+		{"好", strings.ToLower("好")},
+	} {
+
+		expect := strings.Compare(strings.ToLower(test.a), strings.ToLower(test.b))
+		got := compareFold(test.a, test.b)
+
+		assert.Equal(expect, got, fmt.Sprintf("test %d: %d", i, expect))
+
+	}
+}
+
+func TestLexicographicSort(t *testing.T) {
+	assert := require.New(t)
+
+	s := []string{"b", "Bz", "ba", "A", "Ba", "ba"}
+
+	sort.Slice(s, func(i, j int) bool {
+		return LessStrings(s[i], s[j])
+	})
+
+	assert.Equal([]string{"A", "b", "Ba", "ba", "ba", "Bz"}, s)
+
+}