Add unit tests for get

src/utils/object.test.js

@@ -0,0 +1,65 @@
+import {
+  get,
+} from './object.js'
+
+describe('get', () => {
+  it('returns correct value if field exists', () => {
+    const object = {
+      field: 5,
+    }
+    const fieldName = 'field'
+    const defaultValue = 10
+
+    expect(get(object, fieldName, defaultValue)).toBe(5)
+  })
+
+  it('returns correct value if field exists and has falsy value 0', () => {
+    const object = {
+      field: 0,
+    }
+    const fieldName = 'field'
+    const defaultValue = 10
+
+    expect(get(object, fieldName, defaultValue)).toBe(0)
+  })
+
+  it('returns correct value if field exists and has falsy value null', () => {
+    const object = {
+      field: null,
+    }
+    const fieldName = 'field'
+    const defaultValue = 10
+
+    expect(get(object, fieldName, defaultValue)).toBe(null)
+  })
+
+  it('returns default value if is provided and field does not exist', () => {
+    const object = {
+      field: 5,
+    }
+    const fieldName = 'nonExistingField'
+    const defaultValue = 10
+
+    expect(get(object, fieldName, defaultValue)).toBe(10)
+  })
+
+  it('returns correct value if field exists and has falsy value undefined', () => {
+    const object = {
+      field: undefined,
+    }
+    const fieldName = 'field'
+    const defaultValue = 10
+
+    expect(get(object, fieldName, defaultValue)).toBe(undefined)
+  })
+
+  it('throws an error if there is no field and no default value', () => {
+    const object = {
+      field: 'value',
+    }
+    const fieldName = 'nonExistingField'
+    expect(
+      () => get(object, fieldName)
+    ).toThrowError('Required arg "nonExistingField" was not provided')
+  })
+})