How do you test signal inputs, outputs, and OnPush rendering in Angular?

Exercises signal-based component contracts through Angular bindings and waits for scheduled rendering before asserting.

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TL;DR

I create the component through TestBed and supply inputs through setInput, a host component, or Angular's input binding support. I trigger the user action that should emit an output and observe the public event rather than invoking an internal handler. After changing a signal or dispatching a DOM event, I wait for the fixture to become stable before checking the rendered result.

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Signal inputs, outputs, inputBinding, outputBinding, OnPush, TestBed, and rendering stability.

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Core answer
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Overview
Signal-based contracts should be tested as Angular binds and renders them, not by mutating internal state around the framework.
I create the component through TestBed and supply inputs through setInput, a host component, or Angular's input binding support. I trigger the user action that should emit an output and observe the public event rather than invoking an internal handler. After changing a signal or dispatching a DOM event, I wait for the fixture to become stable before checking the rendered result.
Checkpoint
Stronger answer
Optional upgrade with examples, trade-offs, and sharper phrasing.
This matters with OnPush because the test should prove that a real Angular notification schedules the update. Repeatedly forcing detectChanges can hide a production bug where plain mutable state changed without notifying Angular. I cover required inputs, transformed inputs, output payloads, and the case where an equivalent value should not cause unnecessary work. A host component is useful when two-way binding or content projection is part of the contract.

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Details

Assigning a signal input as though it were a normal writable field.
Calling internal event handlers instead of interacting with the DOM.
Using forced change detection to conceal a missing render notification.

How do you test signal inputs, outputs, and OnPush rendering in Angular?

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