diff --git a/src/Array/additional.test.tsx b/src/Array/additional.test.tsx
new file mode 100644
index 00000000..8c6f97d4
--- /dev/null
+++ b/src/Array/additional.test.tsx
@@ -0,0 +1,81 @@
+import {render, screen} from '@testing-library/react'
+import Field from '../Field'
+import Form from '../Form'
+import ArrayField from './index'
+import {FieldProps} from '../types'
+import '@testing-library/jest-dom'
+
+jest.useFakeTimers()
+
+function DummyInput(props: FieldProps) {
+  return (
+    <input
+      value={props.value || ''}
+      onChange={e => props.onChange(e.target.value)}
+    />
+  )
+}
+
+test('autoAddItem renders an empty item when value is empty', () => {
+  const {container} = render(
+    <Form>
+      <Field fieldName="items" type={ArrayField} autoAddItem>
+        <Field fieldName="name" type={DummyInput} />
+      </Field>
+    </Form>,
+  )
+  expect(container.querySelectorAll('input')).toHaveLength(1)
+})
+
+test('renderProps provides the current index', () => {
+  render(
+    <Form state={{items: [{}]}}>
+      <Field fieldName="items" type={ArrayField} renderProps>
+        {index => <div data-testid={`item-${index}`}>Item {index}</div>}
+      </Field>
+    </Form>,
+  )
+  expect(screen.getByTestId('item-0')).toBeInTheDocument()
+})
+
+test('renderItem customizes each item element', () => {
+  render(
+    <Form state={{items: [{name: 'A'}]}}>
+      <Field
+        fieldName="items"
+        type={ArrayField}
+        renderItem={(item, i) => <div data-testid={`custom-${i}`}>{item.name}</div>}
+      />
+    </Form>,
+  )
+  expect(screen.getByTestId('custom-0')).toHaveTextContent('A')
+})
+
+test('honors showAddButton and custom addLabel', () => {
+  const {container} = render(
+    <Form>
+      <Field fieldName="items" type={ArrayField} showAddButton={false} addLabel="Plus">
+        <Field fieldName="name" type={DummyInput} />
+      </Field>
+    </Form>,
+  )
+  expect(screen.queryByText('Plus')).not.toBeInTheDocument()
+  expect(container.querySelector('.srf_addButton')).not.toBeInTheDocument()
+})
+
+test('honors showRemoveButton and custom removeLabel', () => {
+  const {container} = render(
+    <Form state={{items: [{}]}}>
+      <Field
+        fieldName="items"
+        type={ArrayField}
+        showRemoveButton={false}
+        removeLabel="Del"
+      >
+        <Field fieldName="name" type={DummyInput} />
+      </Field>
+    </Form>,
+  )
+  expect(screen.queryByText('Del')).not.toBeInTheDocument()
+  expect(container.querySelector('.srf_removeButton')).not.toBeInTheDocument()
+})
diff --git a/src/Form/getNewValue.additional.test.ts b/src/Form/getNewValue.additional.test.ts
new file mode 100644
index 00000000..d135e35d
--- /dev/null
+++ b/src/Form/getNewValue.additional.test.ts
@@ -0,0 +1,17 @@
+import getNewValue from './getNewValue'
+
+test('supports updater functions', () => {
+  const original = {counter: 1}
+  const result = getNewValue(original, 'counter', n => (n || 0) + 1)
+  expect(result).toEqual({counter: 2})
+  expect(original).toEqual({counter: 1})
+})
+
+test('creates nested objects when missing', () => {
+  const result = getNewValue({}, 'person.name.first', 'John')
+  expect(result).toEqual({person: {name: {first: 'John'}}})
+})
+
+test('throws if path expects object but finds primitive', () => {
+  expect(() => getNewValue({person: 5}, 'person.name', 'John')).toThrow('Expected plain object for key person')
+})
diff --git a/src/Form/index.test.tsx b/src/Form/index.test.tsx
index 9b097a1b..1ccb9684 100644
--- a/src/Form/index.test.tsx
+++ b/src/Form/index.test.tsx
@@ -163,3 +163,38 @@ test('should allow to reset state', () => {
 
   expect(form.getValue()).toEqual({name: 'Nico'})
 })
+
+test('does not render form tag in React Native environment', () => {
+  const original: any = (global as any).navigator
+  Object.defineProperty(global, 'navigator', {
+    value: {product: 'ReactNative'},
+    configurable: true,
+    enumerable: true,
+    writable: true,
+  })
+
+  const {container} = render(
+    <Form>
+      <Field fieldName="name" type={DummyInput} />
+    </Form>,
+  )
+
+  expect(container.querySelector('form')).not.toBeInTheDocument()
+
+  Object.defineProperty(global, 'navigator', {
+    value: original,
+    configurable: true,
+    enumerable: true,
+    writable: true,
+  })
+})
+
+test('passes dom props to the form element', () => {
+  const {container} = render(
+    <Form target="/submit-here">
+      <Field fieldName="name" type={DummyInput} />
+    </Form>,
+  )
+
+  expect(container.querySelector('form').getAttribute('target')).toBe('/submit-here')
+})
diff --git a/src/WithValue/index.test.tsx b/src/WithValue/index.test.tsx
index 5f458896..7c262a10 100644
--- a/src/WithValue/index.test.tsx
+++ b/src/WithValue/index.test.tsx
@@ -1,4 +1,4 @@
-import {render, screen} from '@testing-library/react'
+import {render, screen, fireEvent, act} from '@testing-library/react'
 import React from 'react'
 import Field from '../Field'
 import Form from '../Form'
@@ -7,6 +7,8 @@ import {FieldProps} from '../types'
 import WithValue from './index'
 import '@testing-library/jest-dom'
 
+jest.useFakeTimers()
+
 class DummyInput extends React.Component<FieldProps> {
   render() {
     return (
@@ -59,3 +61,27 @@ it('should pass the value of the form on sub object data', () => {
   const content = screen.getByText('Nicolás')
   expect(content.innerHTML).toBe('Nicolás')
 })
+
+test('updates the render prop when the form value changes', () => {
+  function Test() {
+    const [state, setState] = React.useState({name: ''})
+    return (
+      <Form state={state} onChange={setState}>
+        <WithValue>{value => <div data-testid="val">{value.name}</div>}</WithValue>
+        <Field fieldName="name" type={DummyInput} />
+      </Form>
+    )
+  }
+
+  const {container} = render(<Test />)
+
+  expect(screen.getByTestId('val')).toHaveTextContent('')
+
+  fireEvent.change(container.querySelector('input'), {target: {value: 'John'}})
+
+  act(() => {
+    jest.advanceTimersByTime(0)
+  })
+
+  expect(screen.getByTestId('val')).toHaveTextContent('John')
+})
diff --git a/src/useValue.test.tsx b/src/useValue.test.tsx
new file mode 100644
index 00000000..63dd4fa1
--- /dev/null
+++ b/src/useValue.test.tsx
@@ -0,0 +1,36 @@
+import {render, screen, fireEvent} from '@testing-library/react'
+import React from 'react'
+import {ValueContext} from './Contexts'
+import useValue from './useValue'
+import '@testing-library/jest-dom'
+
+function DisplayValue() {
+  const value = useValue()
+  return <div data-testid="value">{String(value)}</div>
+}
+
+test('useValue returns the current context value', () => {
+  render(
+    <ValueContext.Provider value="context-value">
+      <DisplayValue />
+    </ValueContext.Provider>,
+  )
+  expect(screen.getByTestId('value')).toHaveTextContent('context-value')
+})
+
+test('useValue updates when the context value changes', () => {
+  function Wrapper() {
+    const [val, setVal] = React.useState('first')
+    return (
+      <ValueContext.Provider value={val}>
+        <button onClick={() => setVal('second')}>change</button>
+        <DisplayValue />
+      </ValueContext.Provider>
+    )
+  }
+
+  render(<Wrapper />)
+  expect(screen.getByTestId('value')).toHaveTextContent('first')
+  fireEvent.click(screen.getByText('change'))
+  expect(screen.getByTestId('value')).toHaveTextContent('second')
+})
diff --git a/src/utility/isReactNative.test.tsx b/src/utility/isReactNative.test.tsx
new file mode 100644
index 00000000..27689d10
--- /dev/null
+++ b/src/utility/isReactNative.test.tsx
@@ -0,0 +1,39 @@
+import isReactNative from './isReactNative'
+
+test('returns false in default browser environment', () => {
+  expect(isReactNative()).toBe(false)
+})
+
+test('detects React Native when navigator.product is ReactNative', () => {
+  const original: any = (global as any).navigator
+  Object.defineProperty(global, 'navigator', {
+    value: {product: 'ReactNative'},
+    configurable: true,
+    enumerable: true,
+    writable: true,
+  })
+  expect(isReactNative()).toBe(true)
+  Object.defineProperty(global, 'navigator', {
+    value: original,
+    configurable: true,
+    enumerable: true,
+    writable: true,
+  })
+})
+
+test('returns false when navigator is undefined', () => {
+  const original: any = (global as any).navigator
+  Object.defineProperty(global, 'navigator', {
+    value: undefined,
+    configurable: true,
+    enumerable: true,
+    writable: true,
+  })
+  expect(isReactNative()).toBe(false)
+  Object.defineProperty(global, 'navigator', {
+    value: original,
+    configurable: true,
+    enumerable: true,
+    writable: true,
+  })
+})