Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

analysis/char/asciifolding/asciifolding_test.go

@@ -0,0 +1,124 @@
+//  Copyright (c) 2018 Couchbase, Inc.
+//
+// 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 asciifolding
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func TestAsciiFoldingFilter(t *testing.T) {
+	tests := []struct {
+		input  []byte
+		output []byte
+	}{
+		{
+			// empty input passes
+			input:  []byte(``),
+			output: []byte(``),
+		},
+		{
+			// no modification for plain ASCII
+			input:  []byte(`The quick brown fox jumps over the lazy dog`),
+			output: []byte(`The quick brown fox jumps over the lazy dog`),
+		},
+		{
+			// Umlauts are folded to plain ASCII
+			input:  []byte(`The quick bröwn fox jümps over the läzy dog`),
+			output: []byte(`The quick brown fox jumps over the lazy dog`),
+		},
+		{
+			// composite unicode runes are folded to more than one ASCII rune
+			input:  []byte(`ÆꜴ`),
+			output: []byte(`AEAO`),
+		},
+		{
+			// apples from https://issues.couchbase.com/browse/MB-33486
+			input:  []byte(`Ápple Àpple Äpple Âpple Ãpple Åpple`),
+			output: []byte(`Apple Apple Apple Apple Apple Apple`),
+		},
+		{
+			// Fix ASCII folding of \u24A2
+			input:  []byte(`⒢`),
+			output: []byte(`(g)`),
+		},
+		{
+			// Test folding of \u2053 (SWUNG DASH)
+			input:  []byte(`a⁓b`),
+			output: []byte(`a~b`),
+		},
+		{
+			// Test folding of \uFF5E (FULLWIDTH TILDE)
+			input:  []byte(`c～d`),
+			output: []byte(`c~d`),
+		},
+		{
+			// Test folding of \uFF3F (FULLWIDTH LOW LINE) - case before tilde
+			input:  []byte(`e＿f`),
+			output: []byte(`e_f`),
+		},
+		{
+			// Test mix including tilde and default fallthrough (using a character not explicitly folded)
+			input:  []byte(`a⁓b✅c～d`),
+			output: []byte(`a~b✅c~d`),
+		},
+		{
+			// Test start of 'A' fallthrough block
+			input:  []byte(`ÀBC`),
+			output: []byte(`ABC`),
+		},
+		{
+			// Test end of 'A' fallthrough block
+			input:  []byte(`DEFẶ`),
+			output: []byte(`DEFA`),
+		},
+		{
+			// Test start of 'AE' fallthrough block
+			input:  []byte(`Æ`),
+			output: []byte(`AE`),
+		},
+		{
+			// Test end of 'AE' fallthrough block
+			input:  []byte(`ᴁ`),
+			output: []byte(`AE`),
+		},
+		{
+			// Test 'DZ' multi-rune output
+			input:  []byte(`DŽebra`),
+			output: []byte(`DZebra`),
+		},
+		{
+			// Test start of 'a' fallthrough block
+			input:  []byte(`àbc`),
+			output: []byte(`abc`),
+		},
+		{
+			// Test end of 'a' fallthrough block
+			input:  []byte(`defａ`),
+			output: []byte(`defa`),
+		},
+	}
+
+	for _, test := range tests {
+		filter := New()
+		t.Run(fmt.Sprintf("on %s", test.input), func(t *testing.T) {
+			output := filter.Filter(test.input)
+			if !reflect.DeepEqual(output, test.output) {
+				t.Errorf("\nExpected:\n`%s`\ngot:\n`%s`\n", string(test.output), string(output))
+			}
+		})
+	}
+}