Unify and simplify TrN for i18n (#18141)

Refer: https://github.com/go-gitea/gitea/pull/18135#issuecomment-1003246099

Now we have a unique and simple `TrN`, and make the fix of PR #18135 also use the better `TrN` logic.

4 files changed, 93 insertions, 76 deletions

diff --git a/modules/csv/csv_test.go b/modules/csv/csv_test.go
index d72c3e3a73..1612a66953 100644
--- a/modules/csv/csv_test.go
+++ b/modules/csv/csv_test.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"encoding/csv"
 	"io"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -21,14 +22,21 @@ func TestCreateReader(t *testing.T) {
 	assert.Equal(t, ',', rd.Comma)
 }
 
-//nolint
+func decodeSlashes(t *testing.T, s string) string {
+	s = strings.ReplaceAll(s, "\n", "\\n")
+	s = strings.ReplaceAll(s, "\"", "\\\"")
+	decoded, err := strconv.Unquote(`"` + s + `"`)
+	assert.NoError(t, err, "unable to decode string")
+	return decoded
+}
+
 func TestCreateReaderAndDetermineDelimiter(t *testing.T) {
 	var cases = []struct {
 		csv               string
 		expectedRows      [][]string
 		expectedDelimiter rune
 	}{
-		// case 0 - semicolon delmited
+		// case 0 - semicolon delimited
 		{
 			csv: `a;b;c
 1;2;3
@@ -47,11 +55,11 @@ a,	b	c
 	e	f
 g	h	i
 j		l
-m	n,	
+m	n,\t
 p	q	r
 		u
 v	w	x
-y		
+y\t\t
 		`,
 			expectedRows: [][]string{
 				{"col1", "col2", "col3"},
@@ -74,7 +82,7 @@ y
  a, b, c
 d,e,f
  ,h, i
-j, , 
+j, ,\x20
  , , `,
 			expectedRows: [][]string{
 				{"col1", "col2", "col3"},
@@ -89,7 +97,7 @@ j, ,
 	}
 
 	for n, c := range cases {
-		rd, err := CreateReaderAndDetermineDelimiter(nil, strings.NewReader(c.csv))
+		rd, err := CreateReaderAndDetermineDelimiter(nil, strings.NewReader(decodeSlashes(t, c.csv)))
 		assert.NoError(t, err, "case %d: should not throw error: %v\n", n, err)
 		assert.EqualValues(t, c.expectedDelimiter, rd.Comma, "case %d: delimiter should be '%c', got '%c'", n, c.expectedDelimiter, rd.Comma)
 		rows, err := rd.ReadAll()
@@ -222,7 +230,7 @@ John Doe	john@doe.com	This,note,had,a,lot,of,commas,to,test,delimters`,
 	}
 
 	for n, c := range cases {
-		delimiter := determineDelimiter(&markup.RenderContext{Filename: c.filename}, []byte(c.csv))
+		delimiter := determineDelimiter(&markup.RenderContext{Filename: c.filename}, []byte(decodeSlashes(t, c.csv)))
 		assert.EqualValues(t, c.expectedDelimiter, delimiter, "case %d: delimiter should be equal, expected '%c' got '%c'", n, c.expectedDelimiter, delimiter)
 	}
 }
@@ -287,7 +295,7 @@ abc   | |123
 	}
 
 	for n, c := range cases {
-		modifiedText := removeQuotedString(c.text)
+		modifiedText := removeQuotedString(decodeSlashes(t, c.text))
 		assert.EqualValues(t, c.expectedText, modifiedText, "case %d: modified text should be equal", n)
 	}
 }
@@ -353,7 +361,7 @@ John Doe	john@doe.com	This,note,had,a,lot,of,commas,to,test,delimters`,
 	quoted,
 text,"	a
 2	"some,
-quoted,	
+quoted,\t
 	text,"	b
 3	"some,
 quoted,
@@ -442,7 +450,7 @@ jkl`,
 	}
 
 	for n, c := range cases {
-		delimiter := guessDelimiter([]byte(c.csv))
+		delimiter := guessDelimiter([]byte(decodeSlashes(t, c.csv)))
 		assert.EqualValues(t, c.expectedDelimiter, delimiter, "case %d: delimiter should be equal, expected '%c' got '%c'", n, c.expectedDelimiter, delimiter)
 	}
 }
@@ -459,7 +467,7 @@ func TestGuessFromBeforeAfterQuotes(t *testing.T) {
 	quoted,
 text,"	a
 2	"some,
-quoted,	
+quoted,\t
 	text,"	b
 3	"some,
 quoted,
@@ -534,7 +542,7 @@ a|"he said, ""here I am"""`,
 	}
 
 	for n, c := range cases {
-		delimiter := guessFromBeforeAfterQuotes([]byte(c.csv))
+		delimiter := guessFromBeforeAfterQuotes([]byte(decodeSlashes(t, c.csv)))
 		assert.EqualValues(t, c.expectedDelimiter, delimiter, "case %d: delimiter should be equal, expected '%c' got '%c'", n, c.expectedDelimiter, delimiter)
 	}
 }
@@ -549,6 +557,10 @@ func (l mockLocale) Tr(s string, _ ...interface{}) string {
 	return s
 }
 
+func (l mockLocale) TrN(_cnt interface{}, key1, _keyN string, _args ...interface{}) string {
+	return key1
+}
+
 func TestFormatError(t *testing.T) {
 	var cases = []struct {
 		err             error
diff --git a/modules/templates/helper.go b/modules/templates/helper.go
index a05c0c1a95..fc07b49c71 100644
--- a/modules/templates/helper.go
+++ b/modules/templates/helper.go
@@ -239,7 +239,6 @@ func NewFuncMap() []template.FuncMap {
 		"DisableImportLocal": func() bool {
 			return !setting.ImportLocalPaths
 		},
-		"TrN": TrN,
 		"Dict": func(values ...interface{}) (map[string]interface{}, error) {
 			if len(values)%2 != 0 {
 				return nil, errors.New("invalid dict call")
@@ -857,69 +856,6 @@ func DiffLineTypeToStr(diffType int) string {
 	return "same"
 }
 
-// Language specific rules for translating plural texts
-var trNLangRules = map[string]func(int64) int{
-	"en-US": func(cnt int64) int {
-		if cnt == 1 {
-			return 0
-		}
-		return 1
-	},
-	"lv-LV": func(cnt int64) int {
-		if cnt%10 == 1 && cnt%100 != 11 {
-			return 0
-		}
-		return 1
-	},
-	"ru-RU": func(cnt int64) int {
-		if cnt%10 == 1 && cnt%100 != 11 {
-			return 0
-		}
-		return 1
-	},
-	"zh-CN": func(cnt int64) int {
-		return 0
-	},
-	"zh-HK": func(cnt int64) int {
-		return 0
-	},
-	"zh-TW": func(cnt int64) int {
-		return 0
-	},
-	"fr-FR": func(cnt int64) int {
-		if cnt > -2 && cnt < 2 {
-			return 0
-		}
-		return 1
-	},
-}
-
-// TrN returns key to be used for plural text translation
-func TrN(lang string, cnt interface{}, key1, keyN string) string {
-	var c int64
-	if t, ok := cnt.(int); ok {
-		c = int64(t)
-	} else if t, ok := cnt.(int16); ok {
-		c = int64(t)
-	} else if t, ok := cnt.(int32); ok {
-		c = int64(t)
-	} else if t, ok := cnt.(int64); ok {
-		c = t
-	} else {
-		return keyN
-	}
-
-	ruleFunc, ok := trNLangRules[lang]
-	if !ok {
-		ruleFunc = trNLangRules["en-US"]
-	}
-
-	if ruleFunc(c) == 0 {
-		return key1
-	}
-	return keyN
-}
-
 // MigrationIcon returns a SVG name matching the service an issue/comment was migrated from
 func MigrationIcon(hostname string) string {
 	switch hostname {
diff --git a/modules/test/context_tests.go b/modules/test/context_tests.go
index 1f893122f3..62ec21f6fe 100644
--- a/modules/test/context_tests.go
+++ b/modules/test/context_tests.go
@@ -103,6 +103,10 @@ func (l mockLocale) Tr(s string, _ ...interface{}) string {
 	return s
 }
 
+func (l mockLocale) TrN(_cnt interface{}, key1, _keyN string, _args ...interface{}) string {
+	return key1
+}
+
 type mockResponseWriter struct {
 	httptest.ResponseRecorder
 	size int
diff --git a/modules/translation/translation.go b/modules/translation/translation.go
index 77cc9ac7f5..af1e5d25df 100644
--- a/modules/translation/translation.go
+++ b/modules/translation/translation.go
@@ -17,6 +17,7 @@ import (
 type Locale interface {
 	Language() string
 	Tr(string, ...interface{}) string
+	TrN(cnt interface{}, key1, keyN string, args ...interface{}) string
 }
 
 // LangType represents a lang type
@@ -99,3 +100,67 @@ func (l *locale) Language() string {
 func (l *locale) Tr(format string, args ...interface{}) string {
 	return i18n.Tr(l.Lang, format, args...)
 }
+
+// Language specific rules for translating plural texts
+var trNLangRules = map[string]func(int64) int{
+	// the default rule is "en-US" if a language isn't listed here
+	"en-US": func(cnt int64) int {
+		if cnt == 1 {
+			return 0
+		}
+		return 1
+	},
+	"lv-LV": func(cnt int64) int {
+		if cnt%10 == 1 && cnt%100 != 11 {
+			return 0
+		}
+		return 1
+	},
+	"ru-RU": func(cnt int64) int {
+		if cnt%10 == 1 && cnt%100 != 11 {
+			return 0
+		}
+		return 1
+	},
+	"zh-CN": func(cnt int64) int {
+		return 0
+	},
+	"zh-HK": func(cnt int64) int {
+		return 0
+	},
+	"zh-TW": func(cnt int64) int {
+		return 0
+	},
+	"fr-FR": func(cnt int64) int {
+		if cnt > -2 && cnt < 2 {
+			return 0
+		}
+		return 1
+	},
+}
+
+// TrN returns translated message for plural text translation
+func (l *locale) TrN(cnt interface{}, key1, keyN string, args ...interface{}) string {
+	var c int64
+	if t, ok := cnt.(int); ok {
+		c = int64(t)
+	} else if t, ok := cnt.(int16); ok {
+		c = int64(t)
+	} else if t, ok := cnt.(int32); ok {
+		c = int64(t)
+	} else if t, ok := cnt.(int64); ok {
+		c = t
+	} else {
+		return l.Tr(keyN, args...)
+	}
+
+	ruleFunc, ok := trNLangRules[l.Lang]
+	if !ok {
+		ruleFunc = trNLangRules["en-US"]
+	}
+
+	if ruleFunc(c) == 0 {
+		return l.Tr(key1, args...)
+	}
+	return l.Tr(keyN, args...)
+}