# Selective Testing Analysis

Shows which Xcode test targets were skipped or ran and why test selection changed.

- Repository: https://github.com/tuist/tuist (5859 stars)
- Category: Testing
- License: see repository
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add tuist/tuist --skill analyze-selective-testing -g -a claude-code -y`
Codex: `npx skills add tuist/tuist --skill analyze-selective-testing -g -a codex -y`
Cursor: `npx skills add tuist/tuist --skill analyze-selective-testing -g -a cursor -y`
Gemini CLI: `npx skills add tuist/tuist --skill analyze-selective-testing -g -a gemini-cli -y`

## Description

Analyzes Xcode selective testing effectiveness for a test run, showing which test targets were skipped or ran, and diagnosing regressions in test selection. Can compare two test runs to identify what changed.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Analyze Selective Testing

## Quick Start

1. Run `tuist test list --json` to find test runs.
2. Run `tuist test xcode target list <test-run-id> --json` to see per-target selective testing status.
3. If effectiveness dropped, compare targets between a known-good run and the regressed run.

## Step 1: Resolve Test Runs

### Find the test run to analyze

List recent test runs, optionally filtering by branch:

```bash
tuist test list --json --page-size 10
tuist test list --git-branch feature-x --json --page-size 5
```

Get basic info for a specific test run:

```bash
tuist test show <test-run-id> --json
```

Use this to confirm the run's branch, status, scheme, and environment (`xcode_version`, `macos_version`).

### Defaults

- If no test run is specified, use the most recent CI test run on the current branch.
- For comparison, use the most recent CI test run on the project's default branch.

## Step 2: Drill Into Selective Testing Targets

List per-target selective testing data for a test run:

```bash
tuist test xcode target list <test-run-id> --json
```

Each target includes:
- **name**: The test target name
- **hit_status**: `miss` (ran), `local` (skipped via local cache), or `remote` (skipped via remote cache)
- **hash**: The selective testing hash for this target

Filter by status to focus your analysis:

```bash
tuist test xcode target list <test-run-id> --hit-status miss --json
tuist test xcode target list <test-run-id> --hit-status local --json
tuist test xcode target list <test-run-id> --hit-status remote --json
```

### Assess effectiveness

Count the targets by status:
```
effectiveness = (local_hits + remote_hits) / total_targets * 100
```

The rest: https://github.com/tuist/tuist/blob/HEAD/skills/skills/analyze-selective-testing/SKILL.md