Add ToPascalGoCase and ToCamelGoCase

Author: lavoiesl

strcase/doc.go

@@ -0,0 +1,3 @@
+// Package strcase regroups functions to convert between PascalCase, camelCase, and snake_case.
+// ToPascalGoCase and ToCamelGoCase are also provided, which recognizes some common initialisms and always transforms them to uppercase.
+package strcase

strcase/id.go

@@ -6,16 +6,29 @@ import (
 	"unicode"
 )
 
+// ToPascalCase transforms a string in any form to PascalCase.
 func ToPascalCase(input string) string {
-	return splitJoin(input, 0, 0)
+	return splitJoin(input, 0, 0, false)
 }
 
+// ToPascalGoCase transforms a string in any form to PascalCase, but with recognized initialisms in uppercase, matching the Go style.
+func ToPascalGoCase(input string) string {
+	return splitJoin(input, 0, 0, true)
+}
+
+// ToCamelCase transforms a string in any form to camelCase.
 func ToCamelCase(input string) string {
-	return splitJoin(input, 1, 0)
+	return splitJoin(input, 1, 0, false)
+}
+
+// ToCamelGoCase transforms a string in any form to camelCase, but with recognized initialisms in uppercase, matching the Go style.
+func ToCamelGoCase(input string) string {
+	return splitJoin(input, 1, 0, true)
 }
 
+// ToSnakeCase transforms a string in any form to snake_case.
 func ToSnakeCase(input string) string {
-	return splitJoin(input, math.MaxInt64, '_')
+	return splitJoin(input, math.MaxInt64, '_', false)
 }
 
 func allocateBuilder(input string, separator rune) *strings.Builder {
@@ -35,7 +48,7 @@ func allocateBuilder(input string, separator rune) *strings.Builder {
 	return &b
 }
 
-func splitJoin(input string, firstUpper int, separator rune) string {
+func splitJoin(input string, firstUpper int, separator rune, initialism bool) string {
 	b := allocateBuilder(input, separator)
 	var buf []rune
 	var currentPartIndex int
@@ -51,7 +64,7 @@ func splitJoin(input string, firstUpper int, separator rune) string {
 			b.WriteRune(separator)
 		}
 		if currentPartIndex >= firstUpper {
-			pascalPart(buf)
+			pascalPart(buf, initialism)
 		}
 		for _, r := range buf {
 			b.WriteRune(r)
@@ -85,10 +98,10 @@ func splitJoin(input string, firstUpper int, separator rune) string {
 	return b.String()
 }
 
-// Convert to uppercase if initialism.
+// Convert to uppercase if initialism and `initialism` is true.
 // Convert first rune to uppercase otherwise.
-func pascalPart(part []rune) {
-	if isInitialism(part) {
+func pascalPart(part []rune, initialism bool) {
+	if initialism && isInitialism(part) {
 		for ri, r := range part {
 			part[ri] = unicode.ToUpper(r)
 		}

strcase/id_test.go

@@ -100,10 +100,12 @@ func Benchmark_category(b *testing.B) {
 
 func Test_splitJoin(t *testing.T) {
 	tests := []struct {
-		input  string
-		camel  string
-		pascal string
-		snake  string
+		input    string
+		camel    string
+		camelGo  string
+		pascal   string
+		pascalGo string
+		snake    string
 	}{
 		{
 			// everything empty
@@ -139,10 +141,12 @@ func Test_splitJoin(t *testing.T) {
 			snake:  "aa_bbb",
 		},
 		{
-			input:  "aa_id",
-			pascal: "AaID",
-			camel:  "aaID",
-			snake:  "aa_id",
+			input:    "aa_id",
+			pascal:   "AaId",
+			pascalGo: "AaID",
+			camel:    "aaId",
+			camelGo:  "aaID",
+			snake:    "aa_id",
 		},
 		{
 			input:  "fooBar",
@@ -157,35 +161,52 @@ func Test_splitJoin(t *testing.T) {
 			snake:  "foo_bar",
 		},
 		{
-			input:  "fooUrl",
-			pascal: "FooURL",
-			camel:  "fooURL",
-			snake:  "foo_url",
+			input:    "fooUrl",
+			pascal:   "FooUrl",
+			pascalGo: "FooURL",
+			camel:    "fooUrl",
+			camelGo:  "fooURL",
+			snake:    "foo_url",
 		},
 		{
-			input:  "fooURL",
-			pascal: "FooURL",
-			camel:  "fooURL",
-			snake:  "foo_url",
+			input:    "fooURL",
+			pascal:   "FooUrl",
+			pascalGo: "FooURL",
+			camel:    "fooUrl",
+			camelGo:  "fooURL",
+			snake:    "foo_url",
 		},
 		{
-			input:  "url10",
-			pascal: "URL10",
-			camel:  "url10",
-			snake:  "url_10",
+			input:    "url10",
+			pascal:   "Url10",
+			pascalGo: "URL10",
+			camel:    "url10",
+			snake:    "url_10",
 		},
 		{
-			input:  "url_id",
-			pascal: "URLID",
-			camel:  "urlID",
-			snake:  "url_id",
+			input:    "url_id",
+			pascal:   "UrlId",
+			pascalGo: "URLID",
+			camel:    "urlId",
+			camelGo:  "urlID",
+			snake:    "url_id",
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.input, func(t *testing.T) {
 			require.Equal(t, tt.pascal, ToPascalCase(tt.input))
 			require.Equal(t, tt.camel, ToCamelCase(tt.input))
 			require.Equal(t, tt.snake, ToSnakeCase(tt.input))
+
+			if tt.pascalGo == "" {
+				tt.pascalGo = tt.pascal
+			}
+			require.Equal(t, tt.pascalGo, ToPascalGoCase(tt.input))
+
+			if tt.camelGo == "" {
+				tt.camelGo = tt.camel
+			}
+			require.Equal(t, tt.camelGo, ToCamelGoCase(tt.input))
 		})
 	}
 }