Reportgenerator

ReportGenerator for .NET

Trigger On

• the repo uses or wants ReportGenerator
• CI needs human-readable coverage reports
• multiple coverage files must be merged

Value

• produce a concrete project delta: code, docs, config, tests, CI, or review artifact
• reduce ambiguity through explicit planning, verification, and final validation skills
• leave reusable project context so future tasks are faster and safer

Do Not Use For

• raw coverage collection with no reporting need

Inputs

• the nearest AGENTS.md
• existing coverage artifacts
• desired output formats

Quick Start

1. Read the nearest AGENTS.md and confirm scope and constraints. 2. Run this skill's Workflow through the Ralph Loop until outcomes are acceptable. 3. Return the Required Result Format with concrete artifacts and verification evidence.

Workflow

1. Keep collection and rendering separate: Coverlet collects, ReportGenerator renders. 2. Prefer the local or manifest-based .NET tool for reproducible CI runs. 3. Choose output formats deliberately:

• HtmlSummary
• Cobertura
• MarkdownSummaryGithub
• badges

4. Merge multiple reports only when the repo really needs a consolidated view.

Bootstrap When Missing

If ReportGenerator is not configured yet:

1. Detect current state:

• rg --files -g '.config/dotnet-tools.json'
• dotnet tool list --local
• dotnet tool list --global
• command -v reportgenerator

2. Prefer local tool installation for reproducible CI:

• dotnet new tool-manifest (if missing)
• dotnet tool install dotnet-reportgenerator-globaltool

3. Add one explicit render command to AGENTS.md and CI, for example:

• dotnet tool run reportgenerator -reports:"**/coverage.cobertura.xml" -targetdir:"artifacts/coverage" -reporttypes:"HtmlSummary;Cobertura"

4. Run the report command once and return status: configured or status: improved. 5. If raw coverage outputs are already sufficient and no rendered artifacts are needed, return status: not_applicable.

Deliver

• readable coverage artifacts for humans and CI systems
• explicit report-generation commands

Validate

• report inputs match the generated coverage format
• generated reports land in a stable artifact path

Ralph Loop

Use the Ralph Loop for every task, including docs, architecture, testing, and tooling work.

1. Plan first (mandatory):

• analyze current state
• define target outcome, constraints, and risks
• write a detailed execution plan
• list final validation skills to run at the end, with order and reason

2. Execute one planned step and produce a concrete delta. 3. Review the result and capture findings with actionable next fixes. 4. Apply fixes in small batches and rerun the relevant checks or review steps. 5. Update the plan after each iteration. 6. Repeat until outcomes are acceptable or only explicit exceptions remain. 7. If a dependency is missing, bootstrap it or return status: not_applicable with explicit reason and fallback path.

Required Result Format

• status: complete | clean | improved | configured | not_applicable | blocked
• plan: concise plan and current iteration step
• actions_taken: concrete changes made
• validation_skills: final skills run, or skipped with reasons
• verification: commands, checks, or review evidence summary
• remaining: top unresolved items or none

For setup-only requests with no execution, return status: configured and exact next commands.

Load References

• references/reportgenerator.md
• references/commands.md
• references/formats.md

Example Requests

• "Render coverage as HTML in CI."
• "Merge multiple Coverlet reports."

ReportGenerator CLI Commands

Basic Syntax

reportgenerator [options]

or when installed as a local tool:

dotnet tool run reportgenerator [options]

or shorthand:

dotnet reportgenerator [options]

Required Parameters

Common Parameters

Example Commands

Basic HTML Report

reportgenerator \
  -reports:"**/coverage.cobertura.xml" \
  -targetdir:"artifacts/coverage"

Multiple Output Formats

reportgenerator \
  -reports:"**/coverage.cobertura.xml" \
  -targetdir:"artifacts/coverage" \
  -reporttypes:"Html;Cobertura;MarkdownSummaryGithub;Badges"

Merge Multiple Coverage Files

reportgenerator \
  -reports:"**/coverage.*.xml" \
  -targetdir:"artifacts/coverage" \
  -reporttypes:"Cobertura"

Filter Assemblies

reportgenerator \
  -reports:"coverage.xml" \
  -targetdir:"coverage" \
  -assemblyfilters:"+MyApp.*;-*.Tests"

With History Tracking

reportgenerator \
  -reports:"coverage.xml" \
  -targetdir:"coverage" \
  -historydir:"coverage/history" \
  -reporttypes:"Html"

CI Pipeline with Badge Generation

reportgenerator \
  -reports:"**/coverage.cobertura.xml" \
  -targetdir:"artifacts/coverage" \
  -reporttypes:"HtmlSummary;Cobertura;Badges" \
  -title:"MyProject Coverage" \
  -tag:"$BUILD_NUMBER"

GitHub Actions Summary

reportgenerator \
  -reports:"**/coverage.cobertura.xml" \
  -targetdir:"coverage" \
  -reporttypes:"MarkdownSummaryGithub"

cat coverage/SummaryGithub.md >> $GITHUB_STEP_SUMMARY

Filter Syntax

Filters use prefix notation:

• +Pattern - include items matching pattern
• -Pattern - exclude items matching pattern

Wildcards supported:

• * matches any characters
• Patterns are case-insensitive

Example:

-assemblyfilters:"+MyApp.*;+MyLib.*;-*.Tests;-*.TestUtilities"
-classfilters:"+MyApp.Core.*;-*Generated*"
-filefilters:"-*Designer.cs;-*AssemblyInfo.cs"

Environment Variables

Help

reportgenerator --help
reportgenerator -?

Sources

• ReportGenerator Usage
• ReportGenerator Wiki

ReportGenerator Output Formats

Format Categories

Human-Readable Formats

Markdown Formats

Machine-Readable Formats

Badge Formats

Text Formats

Common Format Combinations

CI Pipeline (GitHub Actions)

-reporttypes:"HtmlSummary;Cobertura;MarkdownSummaryGithub;Badges"

Produces:

• Summary.html - Quick HTML overview for artifact download
• Cobertura.xml - Machine-readable for quality gates
• SummaryGithub.md - Append to $GITHUB_STEP_SUMMARY
• badge_*.svg - Coverage badges for README

CI Pipeline (Azure DevOps)

-reporttypes:"HtmlInline_AzurePipelines;Cobertura"

Local Development

-reporttypes:"Html"

Opens full interactive report with file-level detail.

PR Review

-reporttypes:"MarkdownDeltaSummary;Cobertura"

Shows what changed and maintains machine-readable format.

Merging Reports Only

-reporttypes:"Cobertura"

When the only goal is to merge multiple coverage files into one.

Output File Names

Each format produces specific output files in the target directory:

Badge Examples

Generated badges display coverage percentages:

• Line coverage: badge_linecoverage.svg
• Branch coverage: badge_branchcoverage.svg
• Method coverage: badge_methodcoverage.svg

Usage in README:

`badge_linecoverage.svg`

Or link to raw file URL in GitHub:

![Coverage](https://raw.githubusercontent.com/org/repo/main/artifacts/coverage/badge_linecoverage.svg)

PRO-Only Formats

Some formats require a PRO license:

• MHtml - Single-file MHTML archive
• Risk hotspot analysis features in HTML reports

The core formats listed above are free under Apache 2.0.

Sources

• ReportGenerator Output Formats
• ReportGenerator Wiki

ReportGenerator

Open/Free Status

• open source
• free to use under Apache 2.0
• optional paid PRO features exist, but the core tool is free

Install

Global tool:

dotnet tool install -g dotnet-reportgenerator-globaltool

Local tool:

dotnet new tool-manifest
dotnet tool install dotnet-reportgenerator-globaltool

Verify First

Before installing, check whether the repo already has a local tool manifest or an existing global install:

rg --files -g '.config/dotnet-tools.json'
dotnet tool list --local
dotnet tool list --global
command -v reportgenerator

Common Usage

reportgenerator -reports:"**/coverage.cobertura.xml" -targetdir:"artifacts/coverage" -reporttypes:"HtmlSummary;Cobertura"
dotnet reportgenerator -reports:"**/coverage.cobertura.xml" -targetdir:"artifacts/coverage" -reporttypes:"MarkdownSummaryGithub"

CI Fit

• generate reports into a stable artifact directory
• use one or more machine-readable formats alongside HTML if the pipeline consumes them

When Not To Use

• when raw coverage files are enough and no human-readable output is required

Sources

• ReportGenerator