feat(guards): isEmptyString

src/guards/__tests__/is-empty-string.guard.spec.ts

@@ -0,0 +1,29 @@
+import type { Testcase } from '@tests/utils/types'
+import testSubject from '../is-empty-string.guard'
+
+/**
+ * @file Unit Tests - isEmptyString
+ * @module tutils/guards/tests/unit/isEmptyString
+ */
+
+describe('unit:guards/isEmptyString', () => {
+  type Case = Testcase<boolean> & { state: string; value: any }
+
+  const cases: Case[] = [
+    { expected: false, state: 'array', value: [] },
+    { expected: false, state: 'boolean', value: false },
+    { expected: false, state: 'non-empty string', value: 'string value' },
+    { expected: false, state: 'number', value: 13 },
+    { expected: false, state: 'object', value: { data: 26 } },
+    { expected: true, state: 'empty string (trimmed)', value: '' },
+    { expected: true, state: 'empty string (untrimmed)', value: '   ' }
+  ]
+
+  it.each<Case>(cases)('should return $expected given $state', testcase => {
+    // Arrange
+    const { expected, value } = testcase
+
+    // Act + Expect
+    expect(testSubject(value)).toBe(expected)
+  })
+})

src/guards/index.ts

@@ -4,5 +4,6 @@
  */
 
 export { default as isBooleanish } from './is-booleanish.guard'
+export { default as isEmptyString } from './is-empty-string.guard'
 export { default as isNIL } from './is-nil.guard'
 export { default as isNodeEnv } from './is-node-env.guard'

src/guards/is-empty-string.guard.ts

@@ -0,0 +1,19 @@
+import { EmptyString } from '@tutils/types'
+
+/**
+ * @file Type Guards - isEmptyString
+ * @module tutils/guards/isEmptyString
+ */
+
+/**
+ * Checks if `value` is an empty string.
+ *
+ * @param {any} [value] - Value to check
+ * @return {boolean} `true` if `value` is an empty string
+ */
+const isEmptyString = (value?: any): value is EmptyString => {
+  if (typeof value !== 'string') return false
+  return value.trim() === ''
+}
+
+export default isEmptyString