structuring-a-compose-test

A guide to organizing a Jetpack Compose UI test class, including its test setup, mutable state, and the order of finding, checking, changing, and checking again.

In plain words
What is it for?
Use it when creating or reviewing Compose tests, placing state and setup code, changing state after an assertion, or choosing between Compose test setup styles.
Why use it?
It prevents tests from becoming flaky or unable to change screen state during a test. It also avoids setting up two competing Compose test environments.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/skydoves/android-testing-skills/structuring-a-compose-test
Any agent
npx skills add skydoves/android-testing-skills --skill structuring-a-compose-test
Clone the repo
git clone --depth 1 https://github.com/skydoves/android-testing-skills

Made for: Claude Code, Codex.

Per session 219 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,574 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00219 $0.03574
Opus 5 $0.00110 $0.01787
Sonnet 5 $0.00044 $0.00715
Haiku 4.5 $0.00022 $0.00357

Measured 2d ago against content hash 5aa1d77c63c0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

structuring-a-compose-test scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

compose/patterns/structuring-a-compose-test/SKILL.md · 273 lines

How it starts

The opening of the file, as written. The whole thing — 273 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Structuring a Compose Test — The androidx-Canonical Class Skeleton

Compose tests fail or rot because their structure is wrong, not because the assertions are wrong. State that lives inside setContent { } cannot be driven from the test thread; setContent called inside @Before becomes a hidden race; combining @get:Rule with runComposeUiTest { } creates two competing test environments. This skill encodes the exact class skeleton used by androidx.compose.material3 and androidx.compose.foundation so the developer's tests behave the same way.

When to use this skill

  • The developer is creating a new *Test.kt and asks where to put state, the rule, and setContent.
  • A test compiles but cannot mutate state mid-test ("how do I flip the checkbox after the first assertion?").
  • The developer pasted setContent into @Before and the test is now flaky or will not start.
  • A reviewer flags a test for declaring state inside setContent { }.
  • The developer mixed @get:Rule createComposeRule() and runComposeUiTest { } and gets confusing failures.

When NOT to use this skill

  • The developer is choosing which entry point to use (rule vs. runComposeUiTest); use ../../setup/choosing-test-rule-vs-runtest/SKILL.md.
  • The build cannot resolve createComposeRule; use ../../setup/configuring-test-dependencies/SKILL.md.
  • The decision is host (Robolectric) vs. device (instrumentation); use ../../setup/setting-up-host-vs-device-tests/SKILL.md.
  • The test is specifically for a LazyColumn/LazyRow; layer ../testing-lazy-lists/SKILL.md on top of this skeleton.

Prerequisites

  • androidx.compose.ui:ui-test-junit4 on androidTestImplementation, androidx.compose.ui:ui-test-manifest on debugImplementation. See ../../setup/configuring-test-dependencies/SKILL.md.
  • Default activity is androidx.activity.ComponentActivity (provided by ui-test-manifest). For a custom Activity the androidTest source set MUST declare it in AndroidManifest.xml.
  • Kotlin source set: src/androidTest/kotlin/... (instrumentation) or src/test/kotlin/... (Robolectric host).

Read the full file on GitHub · 273 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 273 lines · 219 tokens per session scan A 5aa1d77c63c0

Subscribe to this mod's changes

structuring-a-compose-test is a skill published in the GitHub repository skydoves/android-testing-skills (313 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 219 tokens to every session and 3,574 once invoked, about $0.0011 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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