feat(guards): isNumber

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

src/guards/__tests__/is-number.spec-d.ts

@@ -0,0 +1,12 @@
+/**
+ * @file Type Tests - isNumber
+ * @module tutils/guards/tests/unit-d/isNumber
+ */
+
+import type testSubject from '../is-number'
+
+describe('unit-d:guards/isNumber', () => {
+  it('should guard number', () => {
+    expectTypeOf<typeof testSubject>().guards.toBeNumber()
+  })
+})

src/guards/__tests__/is-number.spec.ts

@@ -0,0 +1,31 @@
+/**
+ * @file Unit Tests - isNumber
+ * @module tutils/guards/tests/unit/isNumber
+ */
+
+import testSubject from '../is-number'
+
+describe('unit:guards/isNumber', () => {
+  it('should return false if value is not a number', () => {
+    // Arrange
+    const cases: Parameters<typeof testSubject>[] = [
+      [Number.NaN],
+      [faker.datatype.array()],
+      [faker.string.numeric()]
+    ]
+
+    // Act + Expect
+    cases.forEach(([value]) => expect(testSubject(value)).to.be.false)
+  })
+
+  it('should return true if value is a number', () => {
+    // Arrange
+    const cases: Parameters<typeof testSubject>[] = [
+      [faker.number.float()],
+      [faker.number.int()]
+    ]
+
+    // Act + Expect
+    cases.forEach(([value]) => expect(testSubject(value)).to.be.true)
+  })
+})

src/guards/index.ts

@@ -12,3 +12,4 @@ export { default as isEmptyValue } from './is-empty-value'
 export { default as isJwtType } from './is-jwt-type'
 export { default as isNIL } from './is-nil'
 export { default as isNodeEnv } from './is-node-env'
+export { default as isNumber } from './is-number'

src/guards/is-number.ts

@@ -0,0 +1,14 @@
+/**
+ * @file Type Guards - isNumber
+ * @module tutils/guards/isNumber
+ */
+
+/**
+ * Checks if the given `value` is a number.
+ *
+ * @param {unknown} value - Value to evaluate
+ * @return {value is number} `true` if `value` is a number
+ */
+const isNumber = (value: unknown): value is number => Number(value) === value
+
+export default isNumber