NullPointerTester (Guava Testing Library 19.0-rc3 API)

java.lang.Object
- com.google.common.testing.NullPointerTester

```
@Beta
public final class NullPointerTester
extends Object
```
A test utility that verifies that your methods and constructors throw NullPointerException or UnsupportedOperationException whenever null is passed to a parameter that isn't annotated with Nullable.
The tested methods and constructors are invoked -- each time with one parameter being null and the rest not null -- and the test fails if no expected exception is thrown. NullPointerTester uses best effort to pick non-null default values for many common JDK and Guava types, and also for interfaces and public classes that have public parameter-less constructors. When the non-null default value for a particular parameter type cannot be provided by NullPointerTester, the caller can provide a custom non-null default value for the parameter type via setDefault(java.lang.Class<T>, T).

Since:

10.0

Author:

Kevin Bourrillion

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class NullPointerTester.Visibility
Visibility of any method or constructor.

Nested Classes
Modifier and Type	Class and Description
`static class`	`NullPointerTester.Visibility` Visibility of any method or constructor.

Constructor Summary

Constructors
Constructor and Description

NullPointerTester()

Constructors
Constructor and Description
`NullPointerTester()`

Method Summary

Methods
Modifier and Type	Method and Description
`NullPointerTester`	`ignore(Method method)` Ignore `method` in the tests that follow.
`<T> NullPointerTester`	`setDefault(Class<T> type, T value)` Sets a default value that can be used for any parameter of type `type`.
`void`	`testAllPublicConstructors(Class<?> c)` Runs `testConstructor(java.lang.reflect.Constructor<?>)` on every public constructor in class `c`.
`void`	`testAllPublicInstanceMethods(Object instance)` Runs `testMethod(java.lang.Object, java.lang.reflect.Method)` on every public instance method of the class of `instance`, including those inherited from superclasses of the same package.
`void`	`testAllPublicStaticMethods(Class<?> c)` Runs `testMethod(java.lang.Object, java.lang.reflect.Method)` on every public static method of class `c`, including those "inherited" from superclasses of the same package.
`void`	`testConstructor(Constructor<?> ctor)` Verifies that `ctor` produces a `NullPointerException` or `UnsupportedOperationException` whenever any of its non-`Nullable` parameters are null.
`void`	`testConstructorParameter(Constructor<?> ctor, int paramIndex)` Verifies that `ctor` produces a `NullPointerException` or `UnsupportedOperationException` when the parameter in position `paramIndex` is null.
`void`	`testConstructors(Class<?> c, NullPointerTester.Visibility minimalVisibility)` Runs `testConstructor(java.lang.reflect.Constructor<?>)` on every constructor in class `c` that has at least `minimalVisibility`.
`void`	`testInstanceMethods(Object instance, NullPointerTester.Visibility minimalVisibility)` Runs `testMethod(java.lang.Object, java.lang.reflect.Method)` on every instance method of the class of `instance` with at least `minimalVisibility`, including those inherited from superclasses of the same package.
`void`	`testMethod(Object instance, Method method)` Verifies that `method` produces a `NullPointerException` or `UnsupportedOperationException` whenever any of its non-`Nullable` parameters are null.
`void`	`testMethodParameter(Object instance, Method method, int paramIndex)` Verifies that `method` produces a `NullPointerException` or `UnsupportedOperationException` when the parameter in position `paramIndex` is null.
`void`	`testStaticMethods(Class<?> c, NullPointerTester.Visibility minimalVisibility)` Runs `testMethod(java.lang.Object, java.lang.reflect.Method)` on every static method of class `c` that has at least `minimalVisibility`, including those "inherited" from superclasses of the same package.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - NullPointerTester
```
public NullPointerTester()
```
- Method Detail
  - setDefault
```
public <T> NullPointerTester setDefault(Class<T> type,
                               T value)
```
    Sets a default value that can be used for any parameter of type type. Returns this object.
  - ignore
```
public NullPointerTester ignore(Method method)
```
    Ignore method in the tests that follow. Returns this object.
    
    Since:
    
    13.0
  - testConstructors
```
public void testConstructors(Class<?> c,
                    NullPointerTester.Visibility minimalVisibility)
```
    Runs testConstructor(java.lang.reflect.Constructor<?>) on every constructor in class c that has at least minimalVisibility.
  - testAllPublicConstructors
```
public void testAllPublicConstructors(Class<?> c)
```
    Runs testConstructor(java.lang.reflect.Constructor<?>) on every public constructor in class c.
  - testStaticMethods
```
public void testStaticMethods(Class<?> c,
                     NullPointerTester.Visibility minimalVisibility)
```
    Runs testMethod(java.lang.Object, java.lang.reflect.Method) on every static method of class c that has at least minimalVisibility, including those "inherited" from superclasses of the same package.
  - testAllPublicStaticMethods
```
public void testAllPublicStaticMethods(Class<?> c)
```
    Runs testMethod(java.lang.Object, java.lang.reflect.Method) on every public static method of class c, including those "inherited" from superclasses of the same package.
  - testInstanceMethods
```
public void testInstanceMethods(Object instance,
                       NullPointerTester.Visibility minimalVisibility)
```
    Runs testMethod(java.lang.Object, java.lang.reflect.Method) on every instance method of the class of instance with at least minimalVisibility, including those inherited from superclasses of the same package.
  - testAllPublicInstanceMethods
```
public void testAllPublicInstanceMethods(Object instance)
```
    Runs testMethod(java.lang.Object, java.lang.reflect.Method) on every public instance method of the class of instance, including those inherited from superclasses of the same package.
  - testMethod
```
public void testMethod(@Nullable
              Object instance,
              Method method)
```
    Verifies that method produces a NullPointerException or UnsupportedOperationException whenever any of its non-Nullable parameters are null.
    
    Parameters:
    instance - the instance to invoke method on, or null if method is static
  - testConstructor
```
public void testConstructor(Constructor<?> ctor)
```
    Verifies that ctor produces a NullPointerException or UnsupportedOperationException whenever any of its non-Nullable parameters are null.
  - testMethodParameter
```
public void testMethodParameter(@Nullable
                       Object instance,
                       Method method,
                       int paramIndex)
```
    Verifies that method produces a NullPointerException or UnsupportedOperationException when the parameter in position paramIndex is null. If this parameter is marked Nullable, this method does nothing.
    
    Parameters:
    instance - the instance to invoke method on, or null if method is static
  - testConstructorParameter
```
public void testConstructorParameter(Constructor<?> ctor,
                            int paramIndex)
```
    Verifies that ctor produces a NullPointerException or UnsupportedOperationException when the parameter in position paramIndex is null. If this parameter is marked Nullable, this method does nothing.

Class NullPointerTester

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

NullPointerTester

Method Detail

setDefault

ignore

testConstructors

testAllPublicConstructors

testStaticMethods

testAllPublicStaticMethods

testInstanceMethods

testAllPublicInstanceMethods

testMethod

testConstructor

testMethodParameter

testConstructorParameter