Agent skill

Backend Testing

by exceptionless in exceptionless/Exceptionless

Write Exceptionless C tests using local fixtures, HTTP helpers, and controlled time.

Apache-2.0Auto-check passedTesting & QA

Install Backend Testing

skills CLI
$ npx skills add exceptionless/Exceptionless --skill backend-testing -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install exceptionless/Exceptionless backend-testing --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/exceptionless/Exceptionless.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/backend-testing .claude/skills/backend-testing && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
backend-testing
GitHub stars
2.5k
Token cost
~775 tokens
SKILL.md length
334 words
Files
1
Skills in repo
11
Repo updated
First seen
Licence
Apache-2.0

At a glance

Write Exceptionless C tests using local fixtures, HTTP helpers, and controlled time.

  • Testing & QA work in your project
  • SKILL.md covers Unit test structure, Fixtures and locations, HTTP and state and Time
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Backend Testing is an agent skill from exceptionless/Exceptionless. Write Exceptionless C tests using local fixtures, HTTP helpers, and controlled time.

Its SKILL.md is about 780 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Testing & QA. It works with C#. The repository describes itself as: Exceptionless application. The licence is Apache-2.0.

When your agent uses it

  • Testing & QA work in your project

Example prompts

  • “/backend-testing”

What it can do on your machine

Read from SKILL.md and the folder at commit 300e8ca. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Links to these hosts (documentation or services it may open):

    • learn.microsoft.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Backend Testing loads about 775 tokens when it runs. Until then it costs about 25 tokens; SKILL.md has 334 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~25
When it runs · the whole SKILL.md, loaded when a task matches
~775

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from exceptionless/Exceptionless at commit 300e8ca, republished under its Apache-2.0 licence (© exceptionless). 334 words, ~775 tokens.

Download SKILL.mdSave it as .claude/skills/backend-testing/SKILL.md (or your agent's skills folder).
name
backend-testing
description
Write Exceptionless C# tests using local fixtures, HTTP helpers, and controlled time.

Backend Testing

Unit test structure

Follow Microsoft's .NET unit testing best practices.

Organize tests as Arrange–Act–Assert:

  • Arrange: create the subject, minimal input, and required dependencies.
  • Act: perform the behavior under test, awaiting asynchronous work.
  • Assert: check the observable result and relevant side effects. Keep assertions separate from the action.

Keep unit tests fast, isolated, repeatable, and self-checking. Use clear names and minimal setup; test behavior rather than implementation details. Avoid branching or recreating production logic to calculate expected results. Before adding a test, identify the distinct regression it catches and inspect existing coverage. Extend an existing scenario or parameterize equivalent cases instead of duplicating setup. Combine assertions for the same behavior when they share expensive setup, while keeping independent behaviors separately diagnosable. Do not add trivial accessor, framework, or implementation-mirroring tests. Infrastructure-dependent checks belong in integration tests, using the fixtures below. Coverage percentages and test counts alone do not establish test quality.

Use the smallest fixture that proves the behavior. For batching/pagination, cross the real boundary rather than generating arbitrary thousands of records. Keep benchmarks out of the correctness suite. Inspect CI timing reports for expensive tests and preserve automatic shard discovery when restructuring test classes.

Fixtures and locations

Under tests/Exceptionless.Tests/:

  • IntegrationTestsBase.cs and AppWebHostFactory.cs: HTTP/service integration fixtures.
  • TestWithServices.cs: tests needing dependency injection.
  • Api/Endpoints/, Api/Filters/, Api/Handlers/, and Api/Results/: API tests by boundary.
  • Utility/AppSendBuilder.cs: fluent HTTP requests and assertions.
  • Utility/DataBuilder.cs: synthetic records.
  • Utility/ProxyTimeProvider.cs: controlled time.

Name tests MethodUnderTest_Scenario_ExpectedBehavior.

HTTP and state

Use SendRequestAsync with AppSendBuilder and its authorization helpers: AsGlobalAdminUser, AsTestOrganizationUser, AsFreeOrganizationUser, and AsTestOrganizationClientUser. Match an existing endpoint test for the expected response and fixture setup.

Use CreateDataAsync for synthetic data and RefreshDataAsync after database writes when reads require index refresh. ResetDataAsync clears the integration fixture's data; never point these fixtures at production.

Tests use the production serializer. For JSON compatibility, inspect Serializer/ and the relevant API snapshots.

Time

Use the fixture's TimeProvider: Advance, SetUtcNow, and Restore. Prefer controlled time to real waits.

Follow root guidance for focused commands, conditional Aspire startup, and API contract verification.

© exceptionless, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .agents/skills/backend-testing of exceptionless/Exceptionless.

Open the folder on GitHubat commit 300e8ca

Compare with similar skills

Backend Testing next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Backend Testing compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Backend Testing this skillexceptionless/Exceptionless2.5k—~775Automated safety check: PassApache-2.0
Find Untested Sourcesdotnet/skills5.6k1 repos~3.3kAutomated safety check: PassMIT
Macios CI Failure Inspectordotnet/macios2.9k—~2.3kAutomated safety check: PassCustom licence
ScottPlot Test RunnerScottPlot/ScottPlot6.8k—~308Automated safety check: PassMIT
Playwright Rollmicrosoft/playwright-dotnet3k—~1.9kAutomated safety check: PassMIT
Fix Random CI Test Failuredotnet/macios2.9k—~1.3kAutomated safety check: PassCustom licence

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Works with

Categories

Questions about Backend Testing

What does Backend Testing do?

Write Exceptionless C tests using local fixtures, HTTP helpers, and controlled time. Backend Testing is an agent skill from exceptionless/Exceptionless. Write Exceptionless C tests using local fixtures, HTTP helpers, and controlled time.

When should I use Backend Testing?

Backend Testing fits situations like: testing & QA work in your project.

How do I install Backend Testing in Claude Code?

Run `npx skills add exceptionless/Exceptionless --skill backend-testing -a claude-code`. Or copy the skill folder (.agents/skills/backend-testing in exceptionless/Exceptionless) into .claude/skills/backend-testing in your project. Claude Code loads it when a task matches its description.

How do I install Backend Testing in Codex?

Run `npx skills add exceptionless/Exceptionless --skill backend-testing -a codex`. Or copy the skill folder (.agents/skills/backend-testing in exceptionless/Exceptionless) into .agents/skills/backend-testing in your project. Codex loads it when a task matches its description.

Can I use Backend Testing in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add exceptionless/Exceptionless --skill backend-testing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/backend-testing, .gemini/skills/backend-testing, .github/skills/backend-testing and .opencode/skills/backend-testing in your project.

What does Backend Testing need to run?

SKILL.md names no scripts, command-line tools or credentials: Backend Testing is instructions for the agent only.

Does Backend Testing access the network?

SKILL.md names 1 domain. As links in the text: learn.microsoft.com. This is read from the text; nothing was executed.

Is Backend Testing safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Backend Testing use?

Backend Testing is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Backend Testing use?

About 775 tokens (SKILL.md is roughly 3.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Backend Testing?

Skills that share tags, products or a category with Backend Testing: Find Untested Sources (dotnet/skills, 5.6k stars), Macios CI Failure Inspector (dotnet/macios, 2.9k stars), ScottPlot Test Runner (ScottPlot/ScottPlot, 6.8k stars) and Playwright Roll (microsoft/playwright-dotnet, 3k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Backend Testing?

exceptionless (a GitHub organization) maintains it in exceptionless/Exceptionless, which has 2,456 GitHub stars. The repository holds 11 skills in this directory. The repository was last updated on October 8, 2026.

Source: exceptionless/Exceptionless on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.