Merge pull request #283 from colincross/uppercase_properties

Support unpacking capitalized property names

proptools/proptools.go

@@ -16,19 +16,33 @@ package proptools
 
 import (
 	"reflect"
+	"strings"
 	"unicode"
 	"unicode/utf8"
 )
 
+// PropertyNameForField converts the name of a field in property struct to the property name that
+// might appear in a Blueprints file.  Since the property struct fields must always be exported
+// to be accessed with reflection and the canonical Blueprints style is lowercased names, it
+// lower cases the first rune in the field name unless the field name contains multiple runes none
+// of which are lowercase, in which case it returns the field name as-is.
 func PropertyNameForField(fieldName string) string {
 	r, size := utf8.DecodeRuneInString(fieldName)
 	propertyName := string(unicode.ToLower(r))
+	if size == len(fieldName) {
+		return propertyName
+	}
+	if strings.IndexFunc(fieldName[size:], unicode.IsLower) == -1 {
+		return fieldName
+	}
 	if len(fieldName) > size {
 		propertyName += fieldName[size:]
 	}
 	return propertyName
 }
 
+// FieldNameForProperty converts the name of a property that might appear in a Blueprints file to
+// the name of a field in property struct by uppercasing the first rune.
 func FieldNameForProperty(propertyName string) string {
 	r, size := utf8.DecodeRuneInString(propertyName)
 	fieldName := string(unicode.ToUpper(r))

proptools/proptools_test.go

@@ -0,0 +1,94 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// 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 proptools
+
+import "testing"
+
+func TestPropertyNameForField(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{
+			name:  "short",
+			input: "S",
+			want:  "s",
+		},
+		{
+			name:  "long",
+			input: "String",
+			want:  "string",
+		},
+		{
+			name:  "uppercase",
+			input: "STRING",
+			want:  "STRING",
+		},
+		{
+			name:  "mixed",
+			input: "StRiNg",
+			want:  "stRiNg",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := PropertyNameForField(tt.input); got != tt.want {
+				t.Errorf("PropertyNameForField(%v) = %v, want %v", tt.input, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestFieldNameForProperty(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{
+			name:  "short lowercase",
+			input: "s",
+			want:  "S",
+		},
+		{
+			name:  "short uppercase",
+			input: "S",
+			want:  "S",
+		},
+		{
+			name:  "long lowercase",
+			input: "string",
+			want:  "String",
+		},
+		{
+			name:  "long uppercase",
+			input: "STRING",
+			want:  "STRING",
+		},
+		{
+			name:  "mixed",
+			input: "StRiNg",
+			want:  "StRiNg",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := FieldNameForProperty(tt.input); got != tt.want {
+				t.Errorf("FieldNameForProperty(%v) = %v, want %v", tt.input, got, tt.want)
+			}
+		})
+	}
+}

proptools/unpack_test.go

@@ -508,6 +508,21 @@ var validUnpackTestCases = []struct {
 			},
 		},
 	},
+	// Captitalized property
+	{
+		input: `
+			m {
+				CAPITALIZED: "foo",
+			}
+		`,
+		output: []interface{}{
+			&struct {
+				CAPITALIZED string
+			}{
+				CAPITALIZED: "foo",
+			},
+		},
+	},
 }
 
 func TestUnpackProperties(t *testing.T) {