focused-test-selection

name	focused-test-selection
description	Select the smallest meaningful build and test slice to verify a change with minimal cost.

Skill: focused-test-selection

Use when:

• a code change was made
• the user asks what to run
• verification must stay cheap and fast

Goal

Choose the smallest meaningful build/test slice that can falsify the change.

Workflow

1. Identify the touched subsystem:
   • Core
   • FenEngine
   • Host
   • DevTools
   • WebDriver
   • Tests/tooling
2. Choose verification in this order:
   • focused project build
   • focused test class / filter
   • subsystem slice
   • solution build/test only if needed
3. Add runtime artifact checks when rendering/host behavior is involved.

Typical examples

Build only:

• dotnet build FenBrowser.FenEngine/FenBrowser.FenEngine.csproj -c Debug -v minimal

Focused tests:

• dotnet test FenBrowser.Tests/FenBrowser.Tests.csproj --filter "FullyQualifiedName~NameOfRelevantTests" --logger "console;verbosity=minimal"

Rendering checks:

• inspect debug_screenshot.png
• inspect dom_dump.txt
• inspect logs/fenbrowser_*.log

Do not

• default to full solution test runs
• run Test262/WPT unless the task actually touches those surfaces
• claim confidence without a falsifying check

Output contract

1. recommended build command
2. recommended focused test command
3. runtime artifacts to inspect if relevant
4. why this is the smallest sufficient check

Token discipline

• give only the commands that matter
• do not list every possible suite