fix: camel and pascal case transformer (#8034)

Fixes: #7853

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### Tests

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [ ] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I added test coverage for JavaScript changes...
  - [ ] in `web_src/js/*.test.js` if it can be unit tested.
  - [ ] in `tests/e2e/*.test.e2e.js` if it requires interactions with a live Forgejo server (see also the [developer guide for JavaScript testing](https://codeberg.org/forgejo/forgejo/src/branch/forgejo/tests/e2e/README.md#end-to-end-tests)).

### Documentation

- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.

### Release notes

- [x] I do not want this change to show in the release notes.
- [ ] I want the title to show in the release notes with a link to this pull request.
- [ ] I want the content of the `release-notes/<pull request number>.md` to be be used for the release notes instead of the title.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/8034
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Julian Schlarb <julian.schlarb@denktmit.de>
Co-committed-by: Julian Schlarb <julian.schlarb@denktmit.de>

services/repository/generate_test.go

@@ -65,3 +65,30 @@ func TestFileNameSanitize(t *testing.T) {
 	assert.Equal(t, "_", fileNameSanitize("\u0000"))
 	assert.Equal(t, "目标", fileNameSanitize("目标"))
 }
+
+func TestTransformers(t *testing.T) {
+	input := "Foo_Forgejo-BAR"
+
+	tests := []struct {
+		name     string
+		expected string
+	}{
+		{"SNAKE", "foo_forgejo_bar"},
+		{"KEBAB", "foo-forgejo-bar"},
+		{"CAMEL", "fooForgejoBar"},
+		{"PASCAL", "FooForgejoBar"},
+		{"LOWER", "foo_forgejo-bar"},
+		{"UPPER", "FOO_FORGEJO-BAR"},
+		{"TITLE", "Foo_forgejo-Bar"},
+	}
+
+	for i, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tranform := defaultTransformers[i]
+			assert.Equal(t, tt.name, tranform.Name)
+
+			got := tranform.Transform(input)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}