feat: adding testing for the function

test/checkerGmt.test.js

@@ -0,0 +1,48 @@
+const gmthours = require('../index')
+
+describe('hours format', () => {
+  it ('get current hours format', () => {
+    const result = gmthours()
+    expect(result).not.toBeNull()
+  })
+
+  it ('get hours by timestamp', () => {
+    const dateNow = new Date()
+    expect(gmthours(dateNow)).not.toBeNull()
+  })
+
+  it ('get hours by timestamp specifically', () => {
+    const dateNow = new Date(1995, 11, 17)
+    expect(gmthours(dateNow)).toBe('1995/12/17 06:00:00')
+  })
+
+  it ('get hours by time and gmt specifically', () => {
+    const dateNow = new Date(1995, 11, 17)
+    const gmt = 'GMT-05:00'
+    expect(gmthours(dateNow, gmt)).toBe('1995/12/17 01:00:00')
+  })
+})
+
+describe('check bad request', () => {
+  it ('string is not allowed', () => {
+    const stringWord = 'string word'
+    expect(gmthours(stringWord)).toBe(-1)
+  })
+
+  it ('number is not allowed', () => {
+    const numberWord = 10
+    expect(gmthours(numberWord)).toBe(-1)
+  })
+
+  it ('gmt allowed in GMT format', () => {
+    const dateNow = new Date(1995, 11, 17)
+    const gmt = 'esto es un string'
+    expect(gmthours(dateNow, gmt)).toBe(-1)
+  })
+
+  it ('gmt allowed in GMT format', () => {
+    const dateNow = new Date(1995, 11, 17)
+    const gmt = 10
+    expect(gmthours(dateNow, gmt)).toBe(-1)
+  })
+})