Handle common initialisms as the non-first word (#3302)

* Handle common initialisms as the non-first word

Co-authored-by: Sid Feiner <sidfeiner@gmail.com>

* Add wordWalker test

---------

Co-authored-by: Sid Feiner <sidfeiner@gmail.com>

codegen/templates/templates.go

@@ -495,18 +495,18 @@ func wordWalker(str string, f func(*wordInfo)) {
 		if initialisms[upperWord] {
 			// If the uppercase word (string(runes[w:i]) is "ID" or "IP"
 			// AND
-			// the word is the first two characters of the str
+			// the word is the first two characters of the current word
 			// AND
 			// that is not the end of the word
 			// AND
-			// the length of the string is greater than 3
+			// the length of the remaining string is greater than 3
 			// AND
 			// the third rune is an uppercase one
 			// THEN
 			// do NOT count this as an initialism.
 			switch upperWord {
 			case "ID", "IP":
-				if word == str[:2] && !eow && len(str) > 3 && unicode.IsUpper(runes[3]) {
+				if remainingRunes := runes[w:]; word == string(remainingRunes[:2]) && !eow && len(remainingRunes) > 3 && unicode.IsUpper(remainingRunes[3]) {
 					continue
 				}
 			}

codegen/templates/templates_test.go

@@ -53,6 +53,9 @@ func TestToGo(t *testing.T) {
 	require.Equal(t, "Identities", ToGo("identities"))
 	require.Equal(t, "Iphone", ToGo("IPHONE"))
 	require.Equal(t, "IPhone", ToGo("iPHONE"))
+	require.Equal(t, "UserIdentity", ToGo("USER_IDENTITY"))
+	require.Equal(t, "UserIdentity", ToGo("UserIdentity"))
+	require.Equal(t, "UserIdentity", ToGo("userIdentity"))
 }
 
 func TestToGoPrivate(t *testing.T) {
@@ -300,6 +303,10 @@ func Test_wordWalker(t *testing.T) {
 			input:    makeInput("RelatedUrls"),
 			expected: []*wordInfo{{Word: "Related"}, {WordOffset: 1, Word: "Urls"}},
 		},
+		{
+			input:    makeInput("USER_IDENTITY"),
+			expected: []*wordInfo{{Word: "USER"}, {WordOffset: 1, Word: "IDENTITY"}},
+		},
 		{
 			input:    makeInput("ITicket"),
 			expected: []*wordInfo{{Word: "ITicket"}},