msec

Farley Score Plugin for Claude Code

Test quality assessment using Dave Farley's 8 Properties of Good Tests.

Analyses your test suite and produces a Farley Index (0-10) with per-property breakdown, signal evidence, worst offenders, and prioritised recommendations.

Installation

/plugin marketplace add mse-online/farley_score_plugin
/plugin install msec@farley-score-plugin

Or from the shell:

claude plugin marketplace add mse-online/farley_score_plugin
claude plugin install msec@farley-score-plugin

Commands

/msec:farley-score [target]

Autonomous test quality review. Analyses your tests across 8 weighted properties and produces a detailed report with a Farley Index score.

/msec:farley-score              # Welcome menu (first-time users)
/msec:farley-score tests/       # Direct analysis (experienced users)

/msec:farley-score-coach [topic]

Interactive test quality coaching. Teaches you to identify and fix test quality issues through Socratic questioning, guided practice, and score predictions.

/msec:farley-score-coach                    # Welcome menu
/msec:farley-score-coach practice           # Practice with built-in examples
/msec:farley-score-coach mode:intermediate  # Set difficulty level

The 8 Properties of Good Tests

Code	Property	Weight	What It Measures
U	Understandable	1.50x	Tests read like specifications
M	Maintainable	1.50x	Tests verify behavior, not implementation
R	Repeatable	1.25x	Same result every time, anywhere
A	Atomic	1.00x	Isolated, no shared state
N	Necessary	1.00x	Every test adds unique value
G	Granular	1.00x	Single outcome per test
F	Fast	0.75x	Pure computation, no I/O
T	First (TDD)	1.00x	Written before implementation

Rating Scale

Farley Index	Rating
9.0 - 10.0	Exemplary
7.5 - 8.9	Excellent
6.0 - 7.4	Good
4.5 - 5.9	Fair
3.0 - 4.4	Poor
0.0 - 2.9	Critical

Supported Languages

Java (JUnit), Python (pytest, unittest), JavaScript/TypeScript (Jest, Vitest), Go (testing), C# (NUnit, xUnit).

Attribution

• Dave Farley -- 8 Properties of Good Tests
• Andrea Laforgia -- Farley Score methodology, scoring system, and signal detection patterns. Used with permission.
• Bernard McCarty -- Plugin implementation

License

MIT