# What Is Diff-Aware Testing?

## Definition

Diff-aware testing selects or proposes tests using information about a code change. It can use file mappings, dependency analysis or other signals; the exact mechanism depends on the tool.

## Why it matters

A smaller relevant suite can shorten feedback time, but an incomplete mapping can skip an affected user journey. Test selection needs review against shared dependencies and changes in behavior.

## How teams handle it today

Teams combine a baseline regression suite with focused tests selected by the author or reviewer. They validate any automated selection system against known changes before relying on it.

## How Zerocheck approaches it

Zerocheck does not inspect Git diffs to generate or select tests. Choose saved tests in the web app or select YAML paths in the CLI. Describe a new flow or paste checklist items when changed behavior needs a new test.

## Selecting relevant tests without automated diff analysis

Start from the user behavior affected by the pull request. Choose related saved tests and write a new outcome assertion when the requirement changes. Keep a broader regression suite for shared components and dependencies that a narrow selection can miss.

Related terms: [E2E Testing](https://tryzerocheck.com/glossary/e2e-testing/), [PR Gating](https://tryzerocheck.com/glossary/pr-gating/), [Flaky Test](https://tryzerocheck.com/glossary/flaky-test/)


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Canonical: https://tryzerocheck.com/glossary/diff-aware-testing/
Updated: 2026-09-14