microsoft/dry4csharp

microsoft/dry4csharp

Description: Agentic port of https://github.com/unclebob/dry4java

Language: C#

License: CC0-1.0

Stars: 0

Forks: 0

Open issues: 2

Created: 2026-07-26T19:05:49Z

Pushed: 2026-07-27T06:34:32Z

Default branch: master

Fork: no

Archived: no

README:

dry4csharp

Attribution

dry4csharp continues the lineage of Robert C. ("Uncle Bob") Martin's original dry4clj, and is a C# port of its Java sibling dry4java.

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Overview

dry4csharp finds candidate duplicate C# code across files and directories. It reports fuzzy structural matches by filename and line range so another mechanism can evaluate and reduce duplication.

dry4csharp parses C# source with Roslyn, selects C# declarations as comparison candidates, normalizes each candidate's syntax tree, and compares sets of structural fingerprints with Jaccard similarity:

score = shared fingerprints / all fingerprints seen in either candidate

Names and literal values normalize away, while C# syntax shape remains. Type declarations (such as classes, structs, interfaces, records, enums), members (methods, constructors, fields, initializers, enum members), lambdas, expressions, statements, modifiers, and operators all contribute structural nodes.

Usage

dotnet build -c Release
dotnet run --project src/Dry4CSharp -c Release -- [options] [file-or-directory ...]

Options:

--threshold N Minimum structural similarity score, default 0.82
--min-lines N Minimum source lines in a candidate declaration, default 4
--min-nodes N Minimum normalized syntax nodes, default 20
--format F text or edn, default text
--edn Same as --format edn
--text Same as --format text

When no paths are provided, dry4csharp scans src. Directory arguments recursively include .cs files.

Default text output:

DUPLICATE score=0.89
src/App/Invoice.cs:12-25
src/App/Receipt.cs:30-44

EDN output:

{:candidates
[{:score 0.8909090909090909
:left {:file "src/App/Invoice.cs", :start-line 12, :end-line 25}
:right {:file "src/App/Receipt.cs", :start-line 30, :end-line 44}
:left-nodes 88
:right-nodes 91}]}

Development

dotnet test