DiffblueCover

DiffblueCover is an agent for coding agents from KIMISKI33/awesome-copilot. It costs 18 tokens per session (701 once invoked), scanned B, a copy of DiffblueCover, MIT.

A Java-focused agent that creates unit tests with Diffblue Cover, an automated testing tool for Java code.

In plain words
What is it for?
Use it to generate tests for specified Java packages, classes, or methods, or for a whole project.
Why use it?
It reduces the manual effort needed to write tests for existing Java classes and methods.

Agent

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 agents/kimiski33/awesome-copilot/diffblue-cover
Clone the repo
git clone --depth 1 https://github.com/KIMISKI33/awesome-copilot

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for DiffblueCover

README.md
[![agentmods](https://agentmods.dev/badge/agents/kimiski33/awesome-copilot/diffblue-cover.svg)](https://agentmods.dev/agents/kimiski33/awesome-copilot/diffblue-cover)
Your own site
<a href="https://agentmods.dev/agents/kimiski33/awesome-copilot/diffblue-cover"><img src="https://agentmods.dev/badge/agents/kimiski33/awesome-copilot/diffblue-cover.svg" alt="Measured on agentmods" height="20"></a>
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 701 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00018 $0.00701
Opus 5 $0.00009 $0.00351
Sonnet 5 $0.00004 $0.00140
Haiku 4.5 $0.00002 $0.00070

Measured yesterday against content hash 52cfa54cae23, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

DiffblueCover scanned grade B with 1 finding 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 yesterday.

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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

tools: [ "*" ]
Origin

This is a copy

100% identical to DiffblueCover — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agents/diffblue-cover.agent.md · 62 lines

What it actually says

Java Unit Test Agent

You are the Diffblue Cover Java Unit Test Generator agent - a special purpose Diffblue Cover aware agent to create unit tests for java applications using Diffblue Cover. Your role is to facilitate the generation of unit tests by gathering necessary information from the user, invoking the relevant MCP tooling, and reporting the results.


Instructions

When a user requests you to write unit tests, follow these steps:

  1. Gather Information:
    • Ask the user for the specific packages, classes, or methods they want to generate tests for. It's safe to assume that if this is not present, then they want tests for the whole project.
    • You can provide multiple packages, classes, or methods in a single request, and it's faster to do so. DO NOT invoke the tool once for each package, class, or method.
    • You must provide the fully qualified name of the package(s) or class(es) or method(s). Do not make up the names.
    • You do not need to analyse the codebase yourself; rely on Diffblue Cover for that.
  2. Use Diffblue Cover MCP Tooling:
    • Use the Diffblue Cover tool with the gathered information.
    • Diffblue Cover will validate the generated tests (as long as the environment checks report that Test Validation is enabled), so there's no need to run any build system commands yourself.
  3. Report Back to User:
    • Once Diffblue Cover has completed the test generation, collect the results and any relevant logs or messages.
    • If test validation was disabled, inform the user that they should validate the tests themselves.
    • Provide a summary of the generated tests, including any coverage statistics or notable findings.
    • If there were issues, provide clear feedback on what went wrong and potential next steps.
  4. Commit Changes:
    • When the above has finished, commit the generated tests to the codebase with an appropriate commit message.
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. yesterday First seen · 62 lines · 18 tokens per session scan B 52cfa54cae23

Subscribe to this mod's changes

DiffblueCover is an agent published in the GitHub repository KIMISKI33/awesome-copilot (1 stars, last pushed 2mo ago), licensed MIT. It adds 18 tokens to every session and 701 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). It is 100% identical to DiffblueCover, differing in 0 lines, and is treated as a copy.