com.facebook.litho.testing.assertj

Class SubComponentExtractor

java.lang.Object

com.facebook.litho.testing.assertj.SubComponentExtractor

public class SubComponentExtractor
extends Object

An extractor to be used with org.assertj.core.api.Assertions#assertThat.

In most cases you will want to use the #subComponentWith(ComponentContext, Condition) combinator.

Method Summary

Modifier and Type	Method and Description
List<InspectableComponent>	extract(Component input)
static <any>	numOfSubComponents(ComponentContext c, <any> matcher) This combinator allows you to make an assertion on the number of sub-components directly spun up by the component under test.
static SubComponentExtractor	subComponents(ComponentContext c)
static <any>	subComponentWith(ComponentContext c, <any> inner) This combinator allows you to make an assertion that applies to at least one sub-component directly spun up by the component under test.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

extract

public List<InspectableComponent> extract(Component input)

subComponents

public static SubComponentExtractor subComponents(ComponentContext c)

subComponentWith

public static <any> subComponentWith(ComponentContext c,
                                     <any> inner)

This combinator allows you to make an assertion that applies to at least one sub-component directly spun up by the component under test.

Note that this combinator only works on direct child-components, i.e. sub-components not further than one level deep.

If you want to make assertions over deeply nested sub-components, check out SubComponentDeepExtractor#deepSubComponentWith(ComponentContext, Condition).

Example Use

Suppose you've got a MyComponentSpec which takes a text prop and creates multiple children; one of them a Text with a truncated version of your text. You want to verify that there is a direct child present that contains the text that you have passed in:

 mComponent = MyComponent.create(c).text("Cells interlinked within cells interlinked").build();
 assertThat(c, mComponent)
   .has(subComponentWith(c, textEquals("Cells interlink...")))
   .doesNotHave(subComponentWith(c, text(containsString("within cells"))));
 

For more applicable combinators, see below:

Parameters:

c - The ComponentContext used to create the tree.

inner - The condition that at least one sub component needs to match.

See Also:

org.hamcrest.CoreMatchers, ComponentConditions

numOfSubComponents

public static <any> numOfSubComponents(ComponentContext c,
                                       <any> matcher)

This combinator allows you to make an assertion on the number of sub-components directly spun up by the component under test.

Parameters:

c - The ComponentContext used to create the tree.

matcher - The Matcher that verifies the number of sub-components against a condition