Writing Tests With Kotlin Test

Q: What is a Claude Code skill and how does the Writing Tests With Kotlin Test skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Writing Tests With Kotlin Test is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Engineering · Sub-category: testing · Last updated: 2026-05-28

lang:kotlin

Use this skill to write tests with the `kotlin.test` library — the multiplatform assertion + annotation API that compiles the same in `commonTest` and on the JVM (JUnit4 or JUnit5), Android, JS, Native, and Wasm. Covers the `kotlin.test` annotations (`@Test`, `@Ignore`, `@BeforeTest`, `@AfterTest`) and how they typealias onto the underlying framework; the `assert*` functions (`assertEquals`/`assertNotEquals`, `assertSame`, `assertNull`/`assertNotNull`, `assertIs`/`assertIsNot`, `assertContentEquals`, `assertContains`, `assertTrue`/`assertFalse`, `fail`, `expect`, `assertFails`, `assertFailsWith`); the `@OnlyInputTypes` compile-time type check; the `Asserter`/`AsserterContributor`/`DefaultAsserter` extension point that routes JVM failures to `org.junit.Assert` for clickable diffs; and the `kotlin("test")` capability that auto-selects JUnit4 vs JUnit5. Use when the user mentions `kotlin.test`, `import kotlin.test.*`, `@BeforeTest`, `assertFailsWith`, `assertContentEquals`, `assertIs`, or `kotlin("test")`.

About this skill (catalog notes)

Writing Tests With Kotlin Test includes explicit scope boundaries (an explicit 'when not to use' or 'out of scope' section); a dedicated installation section; pricing or quota commentary. At roughly 1,831 words the SKILL.md is on the longer end of the catalog distribution.

License: Apache-2.0
Original author: skydoves
Indexed lastmod: 2026-05-28
Catalog position: Engineering · testing
Indexed related skills: 10

How Writing Tests With Kotlin Test fits the catalog

Writing Tests With Kotlin Test sits in the Engineering category under the testing sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

From the source SKILL.md

kotlin.test is Kotlin's own thin test library: framework-agnostic assert functions plus @Test/@BeforeTest/@AfterTest annotations that typealias onto whatever runner is on the classpath (JUnit4, JUnit5, TestNG, the JS/Native runners). Write import kotlin.test. once and the same test source compiles in commonTest, on the JVM, and on every Kotlin Multiplatform target. This skill covers the API surface, the @OnlyInputTypes compile-time guard, the Asserter extension point, and the Gradle wiring. It is the assertion layer; the runner layer for Android instrumentation is…

What this skill does

Writing Tests With Kotlin Test is a community-contributed Claude Code skill in the testing sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/writing-tests-with-kotlin-test/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when the user mentions `kotlin.test`, `import kotlin.

Who uses this skill

The Writing Tests With Kotlin Test Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 97,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/writing-tests-with-kotlin-test
curl -L https://claudskills.com/skills/writing-tests-with-kotlin-test/SKILL.md \
  -o ~/.claude/skills/writing-tests-with-kotlin-test/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/writing-tests-with-kotlin-test/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/writing-tests-with-kotlin-test/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\writing-tests-with-kotlin-test\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Writing Tests With Kotlin Test Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/writing-tests-with-kotlin-test/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Writing Tests With Kotlin Test skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Writing Tests With Kotlin Test skill?

Use Writing Tests With Kotlin Test when your Claude Code task falls under the Engineering category — specifically in the testing area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Writing Tests With Kotlin Test" or describe the task and let Claude pick). Browse related skills at /category/engineering/.

What is a Claude Code skill and how does the Writing Tests With Kotlin Test skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Writing Tests With Kotlin Test is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/skydoves/android-testing-skills/blob/HEAD/kotlin/kotlin-test/writing-tests-with-kotlin-test/SKILL.md
License: Apache-2.0
Author: skydoves

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

skydoves. (2026). Writing Tests With Kotlin Test [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/writing-tests-with-kotlin-test/

BibTeX

@misc{writing-tests-with-kotlin-test-2026,
  author    = {skydoves},
  title     = {Writing Tests With Kotlin Test [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/writing-tests-with-kotlin-test/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/writing-tests-with-kotlin-test.svg)](https://claudskills.com/skills/writing-tests-with-kotlin-test/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

More Engineering skills

Browse all Engineering skills in the ClaudSkills registry, or explore these other picks from the same category:

Browse all Engineering skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

Part of Acreator Store — Adam Lankamer's AI tools: PerfectStudio · Ucaption · UTagger · AutoXPoster · TestYourSkills · AutomationFlows · Au Naturel · Telegram @acreatorstore