sonar-duplication

name	sonar-duplication
description	Find files with code duplications in a SonarQube project and inspect duplication blocks for a file (project key optional when MCP integration already defines the default project)
argument-hint	[project-key?] [--pr id] [--page-size n] [--page n] [--file key]

SonarQube — Duplication

List files that contain duplicated code in a SonarQube project, then drill into duplication blocks for a specific file when needed.

Usage

sonar-duplication                              # all duplicated files in the current project (auto-paginated)
sonar-duplication my-project                   # duplicated files in a specific project
sonar-duplication my-project --pr 42           # same, on a pull request
sonar-duplication my-project --page-size 100 --page 2   # single page of results (manual pagination)
sonar-duplication my-project --file src/auth/login.py   # duplication detail for one file

Prerequisites

This skill requires the SonarQube MCP Server to be configured and the tools mcp__sonarqube__search_duplicated_files and mcp__sonarqube__get_duplications to be available in your session.

If a tool fails due to authentication problems, ask the user to ensure they have given their consent for automatic token exchange through SonarQube Cloud > My Account > Access Tokens > Agent Apps. Otherwise surface the tool error verbatim and stop.

Instructions

Step 1: Resolve the project key (only when needed)

MCP tools sometimes do not require projectKey when the SonarQube MCP Server has a default project for this workspace (e.g. SONARQUBE_PROJECT_KEY configured in the server env). Resolve a key only when you must pass it (tool schema requires it, or the user targets another project):

• If the user provided a project key, use it.
• Otherwise look for sonar.projectKey in sonar-project.properties at the repo root.
• If still not found, omit projectKey in MCP calls and rely on the integration default.

Step 2: Parse optional flags from the user-provided arguments

Flag	Meaning
--pr <id>	Pull request context (maps to pullRequest)
--page-size <n>	Results per page for manual pagination only; integer 1–500 (maps to pageSize)
--page <n>	Page number for manual pagination; starts at 1 (maps to pageIndex)
--file <key>	Skip the duplicated-files list; fetch duplication blocks for this file (maps to key in get_duplications)

Pagination rule: By default, call search_duplicated_files without pageSize or pageIndex so the MCP server auto-fetches every page of duplicated files (up to 10,000 files). Use pageSize and pageIndex only when the user asks for a specific page or wants to limit page size. If the user supplies --page-size but not --page, use pageIndex 1.

Step 3: Run the appropriate flow

Flow A — Duplicated file list (default, no --file)

Call mcp__sonarqube__search_duplicated_files.

Default (auto-fetch all pages):

Include projectKey only if you resolved one in Step 1 and the tool requires it; otherwise omit it.

{
  "projectKey": "<only-if-required>",
  "pullRequest": "<id>"
}

Omit pullRequest when --pr was not given. Omit pageSize and pageIndex entirely so all duplicated files are retrieved automatically. Omit projectKey from the payload when the integration default applies.

Manual pagination (single page):

{
  "projectKey": "<only-if-required>",
  "pullRequest": "<id>",
  "pageSize": <n>,
  "pageIndex": <n>
}

The tool returns only files that have duplications. Present results in a table. Include columns the response provides (for example path, duplicated line counts, or density); sort by the strongest duplication signal if multiple metrics exist (for example highest duplicated-lines density or count first).

## Duplication — `my-project`

Files with duplications:

| File                 | Duplicated lines (example) |
| -------------------- | -------------------------- |
| src/auth/login.py    | 42                         |
| src/utils/helpers.py | 18                         |

If the list is empty: "No duplicated files were returned for this project/branch/PR."

Then offer to drill in:

"Ask me to open duplications for any file, or invoke the sonar-duplication skill with --file <file-key> (add a project key only if needed)."

Flow B — Duplication detail (--file <key> given, or user asks to inspect a file)

Call mcp__sonarqube__get_duplications:

{
  "key": "<file-key>",
  "pullRequest": "<id>"
}

The file key format is <projectKey>:<path>, e.g. my-project:src/auth/login.py. If the user provides just a path, prepend the resolved project key when you have one; otherwise follow the MCP tool schema for the default project. Omit pullRequest when --pr was not given.

Permission: This call requires Browse permission on the file’s project. If the tool returns a permission or authorization error, tell the user they need the Browse role on the project and that they may need a role with code-view access.

Present duplication blocks from the response: for each block, show ranges, sibling copies, or other fields returned by the API so the user can see where code is duplicated.

## Duplication detail — `src/auth/login.py`

### Block 1
- Lines 10–24 (example) duplicated in `src/other/helper.py` lines 30–44
...

If the file has no duplications in the response, say: "No duplications were reported for this file."

Step 4: Next steps

• To refactor: "Ask me to extract a shared helper or consolidate the duplicated regions."
• To check the quality gate (e.g. new_duplicated_lines_density): "Invoke the sonar-quality-gate skill (add a project key only if you are not using the integration default)."