BoundedDiagnosingMatcher

public abstract class BoundedDiagnosingMatcher
extends BaseMatcher<S>

java.lang.Object
   ↳ org.hamcrest.BaseMatcher<S>
     ↳ androidx.test.espresso.matcher.BoundedDiagnosingMatcher<S, T extends S>


A matcher that allows for a quick creation of a matcher that applies to a given type but only processes items of a specific subtype of that matcher. Additional interfaces can be applied. This class is syntactic sugar for Matchers.instanceOf(Class) where the first argument is the base class and the remaining optional arguments are interfaces.

Summary

Public constructors

BoundedDiagnosingMatcher(Class<? extends S> expectedType)
BoundedDiagnosingMatcher(Class<? extends S> expectedType, Class<?> interfaceType1, Class...<?> otherInterfaces)

Public methods

final void describeMismatch(Object item, Description mismatchDescription)

This method provides a default implementation for null check as well as a super type and interface checks provided by the constructor.

final void describeTo(Description description)
final boolean matches(Object item)

Protected methods

abstract void describeMoreTo(Description description)

Subclasses should implement this.

abstract boolean matchesSafely(T item, Description mismatchDescription)

Subclasses should implement this.

Inherited methods

Public constructors

BoundedDiagnosingMatcher

public BoundedDiagnosingMatcher (Class<? extends S> expectedType)

Parameters
expectedType Class

BoundedDiagnosingMatcher

public BoundedDiagnosingMatcher (Class<? extends S> expectedType, 
                Class<?> interfaceType1, 
                Class...<?> otherInterfaces)

Parameters
expectedType Class

interfaceType1 Class

otherInterfaces Class

Public methods

describeMismatch

public final void describeMismatch (Object item, 
                Description mismatchDescription)

This method provides a default implementation for null check as well as a super type and interface checks provided by the constructor. Failing either check provides a default mismatch description. Passing both will call into matchesSafely(Object, Description) which will allow the sub-class to check for a mismatch and describe what went wrong (if anything at all).

Parameters
item Object: The item which is assumed to have mismatched and should be described.

mismatchDescription Description: The description builder for the mismatch.

describeTo

public final void describeTo (Description description)

Parameters
description Description

matches

public final boolean matches (Object item)

Parameters
item Object

Returns
boolean

Protected methods

describeMoreTo

protected abstract void describeMoreTo (Description description)

Subclasses should implement this. The fine details of the matcher should be added to the description. Type checking information will have already been added.

Parameters
description Description: The Description object to write to.

matchesSafely

protected abstract boolean matchesSafely (T item, 
                Description mismatchDescription)

Subclasses should implement this. The item will already have been checked for the specific type, interfaces, and will never be null.

Parameters
item T: The pre-checked item.

mismatchDescription Description: A Description to write to for mismatches.

Returns
boolean true if the item matches the expectations for this Matcher.