Add preserveConsecutiveUppercase option (#115)

index.d.ts

@@ -41,6 +41,7 @@ export type CamelCaseKeys<
 	T extends ObjectOptional | readonly any[],
 	Deep extends boolean = false,
 	IsPascalCase extends boolean = false,
+	PreserveConsecutiveUppercase extends boolean = false,
 	Exclude extends readonly unknown[] = EmptyTuple,
 	StopPaths extends readonly string[] = EmptyTuple,
 	Path extends string = '',
@@ -52,6 +53,7 @@ export type CamelCaseKeys<
 			T[P],
 			Deep,
 			IsPascalCase,
+			PreserveConsecutiveUppercase,
 			Exclude,
 			StopPaths
 			>
@@ -64,7 +66,7 @@ export type CamelCaseKeys<
 				? P
 				: [IsPascalCase] extends [true]
 					? PascalCase<P>
-					: CamelCase<P>]: [IsInclude<StopPaths, AppendPath<Path, P & string>>] extends [
+					: CamelCase<P, {preserveConsecutiveUppercase: PreserveConsecutiveUppercase}>]: [IsInclude<StopPaths, AppendPath<Path, P & string>>] extends [
 				true,
 			]
 				? T[P]
@@ -74,6 +76,7 @@ export type CamelCaseKeys<
 						T[P],
 						Deep,
 						IsPascalCase,
+						PreserveConsecutiveUppercase,
 						Exclude,
 						StopPaths,
 						AppendPath<Path, P & string>
@@ -145,6 +148,14 @@ type Options = {
 	@default false
 	*/
 	readonly pascalCase?: boolean;
+
+	/**
+	Preserve consecutive uppercase characters: `foo_BAR` → `FooBAR`.
+
+	@default false
+	*/
+	readonly preserveConsecutiveUppercase?: boolean;
+
 };
 
 /**
@@ -197,6 +208,7 @@ export default function camelcaseKeys<
 T,
 WithDefault<OptionsType['deep'], false>,
 WithDefault<OptionsType['pascalCase'], false>,
+WithDefault<OptionsType['preserveConsecutiveUppercase'], false>,
 WithDefault<OptionsType['exclude'], EmptyTuple>,
 WithDefault<OptionsType['stopPaths'], EmptyTuple>
 >;

index.js

@@ -32,6 +32,7 @@ const transform = (input, options = {}) => {
 		pascalCase = false,
 		stopPaths,
 		deep = false,
+		preserveConsecutiveUppercase = false,
 	} = options;
 
 	const stopPathsSet = new Set(stopPaths);
@@ -51,7 +52,7 @@ const transform = (input, options = {}) => {
 			if (cache.has(cacheKey)) {
 				key = cache.get(cacheKey);
 			} else {
-				const returnValue = camelCase(key, {pascalCase, locale: false});
+				const returnValue = camelCase(key, {pascalCase, locale: false, preserveConsecutiveUppercase});
 
 				if (key.length < 100) { // Prevent abuse
 					cache.set(cacheKey, returnValue);

index.test-d.ts

@@ -81,6 +81,31 @@ expectType<{FooBar: {FooBar: {FooBar: boolean}}}>(
 	),
 );
 
+expectType<{fooBAR: boolean}>(
+	camelcaseKeys({'foo-BAR': true}, {preserveConsecutiveUppercase: true}),
+);
+expectType<{readonly fooBAR: true}>(
+	camelcaseKeys({foo_BAR: true} as const, {preserveConsecutiveUppercase: true}),
+);
+expectType<{fooBAR: boolean}>(
+	camelcaseKeys({'--foo-BAR': true}, {preserveConsecutiveUppercase: true}),
+);
+expectType<{fooBAR: boolean}>(
+	camelcaseKeys({foo_BAR: true}, {preserveConsecutiveUppercase: true}),
+);
+expectType<{fooBAR: boolean}>(
+	camelcaseKeys({'foo BAR': true}, {preserveConsecutiveUppercase: true}),
+);
+expectType<{FooBAR: boolean}>(
+	camelcaseKeys({'foo BAR': true}, {preserveConsecutiveUppercase: true, pascalCase: true}),
+);
+expectType<{fooBAR: {fooBAR: {fooBAR: boolean}}}>(
+	camelcaseKeys(
+		{'foo-BAR': {foo_BAR: {'foo BAR': true}}},
+		{deep: true, preserveConsecutiveUppercase: true},
+	),
+);
+
 expectType<{fooBar: boolean; foo_bar: true}>(
 	camelcaseKeys(
 		{'foo-bar': true, foo_bar: true},
@@ -193,13 +218,13 @@ expectType<CamelCaseKeys<typeof nestedItem, true, true>>(
 const data = {'foo-bar': true, foo_bar: true};
 const exclude = ['foo', 'foo_bar', /bar/] as const;
 
-expectType<CamelCaseKeys<typeof data, false, false, typeof exclude>>(
+expectType<CamelCaseKeys<typeof data, false, false, false, typeof exclude>>(
 	camelcaseKeys(data, {exclude}),
 );
 
 const nonNestedWithStopPathData = {'foo-bar': true, foo_bar: true};
 expectType<
-CamelCaseKeys<typeof nonNestedWithStopPathData, false, false, ['foo']>
+CamelCaseKeys<typeof nonNestedWithStopPathData, false, false, false, ['foo']>
 >(camelcaseKeys({'foo-bar': true}, {stopPaths: ['foo']}));
 const nestedWithStopPathData = {
 	'top-level': {'foo-bar': {'bar-baz': true}},
@@ -211,6 +236,7 @@ CamelCaseKeys<
 	typeof nestedWithStopPathData,
 true,
 false,
+false,
 // eslint-disable-next-line @typescript-eslint/ban-types
 [],
 	typeof stopPaths

readme.md

@@ -27,6 +27,12 @@ camelcaseKeys({'foo-bar': true, nested: {unicorn_rainbow: true}}, {deep: true});
 camelcaseKeys({a_b: 1, a_c: {c_d: 1, c_e: {e_f: 1}}}, {deep: true, stopPaths: ['a_c.c_e']}),
 //=> {aB: 1, aC: {cD: 1, cE: {e_f: 1}}}
 
+// preserve Uppercase if they are consecutive
+camelcaseKeys({'foo-BAR': true, nested: {unicorn_RAINbow: true}}, {deep: true, preserveConsecutiveUppercase: false});
+//=> {fooBar: true, nested: {unicornRainbow: true}}
+camelcaseKeys({'foo-BAR': true, nested: {unicorn_RAINbow: true}}, {deep: true, preserveConsecutiveUppercase: true});
+//=> {fooBAR: true, nested: {unicornRAINbow: true}}
+
 // Convert object keys to pascal case
 camelcaseKeys({'foo-bar': true, nested: {unicorn_rainbow: true}}, {deep: true, pascalCase: true});
 //=> {FooBar: true, Nested: {UnicornRainbow: true}}
@@ -113,6 +119,13 @@ Default: `false`
 
 Uppercase the first character as in `bye-bye` → `ByeBye`.
 
+##### preserveConsecutiveUppercase
+
+Type: `boolean`\
+Default: `false`
+
+Preserve consecutive uppercase characters: `foo-BAR` → `FooBAR` if true vs `foo-BAR` → `FooBar` if false
+
 ## Related
 
 - [decamelize-keys](https://github.com/sindresorhus/decamelize-keys) - The inverse of this package

test.js

@@ -52,6 +52,19 @@ test('stopPaths option', t => {
 	);
 });
 
+test('preserveConsecutiveUppercase option only', t => {
+	// eslint-disable-next-line camelcase
+	t.true(camelcaseKeys({new_foo_BAR: true}, {preserveConsecutiveUppercase: true}).newFooBAR);
+});
+
+test('preserveConsecutiveUppercase and deep options', t => {
+	t.deepEqual(
+		// eslint-disable-next-line camelcase
+		camelcaseKeys({p_FOO_bar: true, p_obj: {p_two: false, p_arr: [{p_THREE_four: true}]}}, {deep: true, preserveConsecutiveUppercase: true}),
+		{pFOOBar: true, pObj: {pTwo: false, pArr: [{pTHREEFour: true}]}},
+	);
+});
+
 test('pascalCase option only', t => {
 	t.true(camelcaseKeys({'new-foo-bar': true}, {pascalCase: true}).NewFooBar);
 });