backend-testing

Write comprehensive backend tests including unit tests, integration tests, and API tests. Use when testing REST APIs, database operations, authentication flows, or business logic. Handles Jest, Pytest, Mocha, testing strategies, mocking, and test coverage.

Install with Tessl CLI

npx tessl i github:supercent-io/skills-template --skill backend-testing

What are skills?

1.21x

Quality

71%

Does it follow best practices?

Impact

96%

1.21x

Average score across 3 eval scenarios

Optimize this skill with Tessl

npx tessl skill review --optimize ./.agent-skills/backend-testing/SKILL.md

SKILL.md

Review

Evals

Evaluation results

97%

44%

Bootstrap Test Infrastructure for an Express TypeScript API

Jest test environment configuration

Criteria

Without context

With context

ts-jest preset

100%

node test environment

100%

roots in src

50%

100%

testMatch pattern

100%

coverageThreshold at 80

100%

setupFilesAfterEnv

16%

100%

beforeEach DB reset

100%

afterEach DB rollback

100%

afterAll connection close

100%

env.test file

100%

directory structure

62%

test script

100%

test:coverage script

100%

test:ci script

50%

100%

Without context: $0.6856 · 2m 49s · 41 turns · 43 in / 9,615 out tokens

With context: $0.6825 · 1m 37s · 31 turns · 216 in / 6,359 out tokens

99%

Write Unit Tests for a Notification Service

Unit test mocking and isolation

Criteria

Without context

With context

Mock external API

100%

Mock email service

100%

Fake timers for expiry

80%

100%

AAA structure

75%

87%

Clear test names

100%

Test isolation — beforeEach reset

100%

Edge case coverage

100%

No hardcoded secrets

100%

Mock cleared after time test

100%

Isolation from real DB

100%

Mock called assertions

100%

Without context: $0.5119 · 2m 9s · 26 turns · 31 in / 8,064 out tokens

With context: $0.8111 · 2m 40s · 33 turns · 283 in / 9,506 out tokens

92%

Write Integration Tests for a FastAPI User Management API

FastAPI integration and auth testing

Criteria

Without context

With context

In-memory SQLite

100%

Dependency injection override

100%

Override cleared after tests

100%

Success status code 201

100%

Failure status code 4xx

100%

Response body structure check

100%

DB state verification

100%

401 without token

62%

75%

200 with valid token

100%

Role-based 403

100%

Error message validation

100%

Async test functions

Function-scoped fixtures

70%

100%

Without context: $0.9046 · 3m 17s · 42 turns · 43 in / 11,873 out tokens

With context: $1.2063 · 3m 6s · 48 turns · 297 in / 12,232 out tokens

Evaluated: 3 days ago
Agent: Claude Code
Model: Claude Sonnet 4.6

Table of Contents

Bootstrap Test Infrastructure for an Express TypeScript API Write Unit Tests for a Notification Service Write Integration Tests for a FastAPI User Management API

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.