sandi-metz-rules

This skill should be used when users request code review, refactoring, or code quality improvements for Ruby codebases. Apply Sandi Metz's four rules for writing maintainable object-oriented code - classes under 100 lines, methods under 5 lines, no more than 4 parameters, and controllers instantiate only one object. Use when users mention "Sandi Metz", "code quality", "refactoring", or when reviewing Ruby code for maintainability.

1.17x

Quality

71%

Does it follow best practices?

Impact

100%

1.17x

Average score across 3 eval scenarios

Securityby

Passed

No known issues

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Evaluation results

100%

14%

Ruby Code Quality Audit

Precise code measurement rules

Criteria

Without context

With context

Method line counting

100%

Blank lines excluded from methods

100%

Block param excluded

100%

Keyword args counted as params

100%

Default params counted

50%

100%

Class line counting

100%

Violation prioritization

100%

Routes DSL acceptable

100%

Specific line numbers

100%

Method extraction suggestion

100%

Parameter object suggestion

100%

11%

Ruby Codebase Health Review

Full codebase review with refactoring examples

Criteria

Without context

With context

File locations and line numbers

100%

Largest violations identified first

100%

Parameter violation flagged

100%

Method length violation flagged

25%

100%

Prioritized severity list

100%

Named pattern for long method

70%

100%

Named pattern for too many params

100%

Before/after for parameter violation

100%

Before/after for method length

80%

100%

Refactoring benefit explained

100%

Summary statistics

100%

20%

Rails Controller Cleanup and Enforcement Setup

Fat controller refactoring and automation

Criteria

Without context

With context

Single object instantiation

100%

Finder calls not counted

100%

Named extraction pattern

100%

Before/after controller comparison

100%

RuboCop ClassLength limit

100%

RuboCop MethodLength limit

100%

RuboCop ParameterLists limit

100%

Additional tools mentioned

100%

Violation counts identified

100%

Service object handles full flow

100%

Repository: Dicklesworthstone/pi_agent_rust
Commit: 47823e3

Evaluated: about 1 month ago
Agent: Claude Code
Model: Claude Sonnet 4.6

Table of Contents

Ruby Code Quality Audit Ruby Codebase Health Review Rails Controller Cleanup and Enforcement Setup

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