feat(utils): isLowercase, isUppercase

Signed-off-by: Lexus Drumgold <[email protected]>

src/utils/__tests__/is-lowercase.spec-d.ts

@@ -0,0 +1,12 @@
+/**
+ * @file Type Tests - isLowercase
+ * @module tutils/utils/tests/unit-d/isLowercase
+ */
+
+import type testSubject from '../is-lowercase'
+
+describe('unit-d:utils/isLowercase', () => {
+  it('should guard Lowercase<T>', () => {
+    expectTypeOf<typeof testSubject>().guards.toEqualTypeOf<Lowercase<string>>()
+  })
+})

src/utils/__tests__/is-lowercase.spec.ts

@@ -0,0 +1,16 @@
+/**
+ * @file Unit Tests - isLowercase
+ * @module tutils/utils/tests/unit/isLowercase
+ */
+
+import testSubject from '../is-lowercase'
+
+describe('unit:utils/isLowercase', () => {
+  it('should return false if value is not lowercase string', () => {
+    expect(testSubject(faker.string.sample().toUpperCase())).to.be.false
+  })
+
+  it('should return true if value is lowercase string', () => {
+    expect(testSubject(faker.string.sample().toLowerCase())).to.be.true
+  })
+})

src/utils/__tests__/is-uppercase.spec-d.ts

@@ -0,0 +1,12 @@
+/**
+ * @file Type Tests - isUppercase
+ * @module tutils/utils/tests/unit-d/isUppercase
+ */
+
+import type testSubject from '../is-uppercase'
+
+describe('unit-d:utils/isUppercase', () => {
+  it('should guard Uppercase<T>', () => {
+    expectTypeOf<typeof testSubject>().guards.toEqualTypeOf<Uppercase<string>>()
+  })
+})

src/utils/__tests__/is-uppercase.spec.ts

@@ -0,0 +1,16 @@
+/**
+ * @file Unit Tests - isUppercase
+ * @module tutils/utils/tests/unit/isUppercase
+ */
+
+import testSubject from '../is-uppercase'
+
+describe('unit:utils/isUppercase', () => {
+  it('should return false if value is not uppercase string', () => {
+    expect(testSubject(faker.string.sample().toLowerCase())).to.be.false
+  })
+
+  it('should return true if value is uppercase string', () => {
+    expect(testSubject(faker.string.sample().toUpperCase())).to.be.true
+  })
+})

src/utils/index.ts

@@ -11,6 +11,7 @@ export { default as isEmptyString } from './is-empty-string'
 export { default as isEmptyValue } from './is-empty-value'
 export { default as isFunction } from './is-function'
 export { default as isJsonPrimitive } from './is-json-primitive'
+export { default as isLowercase } from './is-lowercase'
 export { default as isNIL } from './is-nil'
 export { default as isNodeEnv } from './is-node-env'
 export { default as isNull } from './is-null'
@@ -21,5 +22,6 @@ export { default as isPrimitive } from './is-primitive'
 export { default as isString } from './is-string'
 export { default as isSymbol } from './is-symbol'
 export { default as isUndefined } from './is-undefined'
+export { default as isUppercase } from './is-uppercase'
 export { default as lowercase } from './lowercase'
 export { default as uppercase } from './uppercase'

src/utils/is-lowercase.ts

@@ -0,0 +1,19 @@
+/**
+ * @file Utilities - isLowercase
+ * @module tutils/utils/isLowercase
+ */
+
+import isString from './is-string'
+import lowercase from './lowercase'
+
+/**
+ * Checks if `value` is a lowercase string.
+ *
+ * @param {unknown} value - Value to check
+ * @return {value is Lowercase<string>} `true` if `value` is lowercase string
+ */
+const isLowercase = (value: unknown): value is Lowercase<string> => {
+  return isString(value) && value === lowercase(value)
+}
+
+export default isLowercase

src/utils/is-uppercase.ts

@@ -0,0 +1,19 @@
+/**
+ * @file Utilities - isUppercase
+ * @module tutils/utils/isUppercase
+ */
+
+import isString from './is-string'
+import uppercase from './uppercase'
+
+/**
+ * Checks if `value` is an uppercase string.
+ *
+ * @param {unknown} value - Value to check
+ * @return {value is Uppercase<string>} `true` if `value` is uppercase string
+ */
+const isUppercase = (value: unknown): value is Uppercase<string> => {
+  return isString(value) && value === uppercase(value)
+}
+
+export default isUppercase