dm-metrics

Description

Robert C. Martin's packages dependency management metrics for Pharo.

Details

Source

GitHub

Dialect

pharo (65% confidence)

License

MIT

Stars

2

Forks

2

Created

Nov. 20, 2018

Updated

March 10, 2026

Topics

metrics pharo quality-assurance smalltalk

README excerpt

# DMMetrics

[![Build Status](https://travis-ci.org/luque/dm-metrics.svg?branch=master)](https://travis-ci.org/luque/dm-metrics)
[![Coverage Status](https://coveralls.io/repos/github/luque/dm-metrics/badge.svg?branch=master)](https://coveralls.io/github/luque/dm-metrics?branch=master)

DMMetrics is a library to compute [Robert C. Martin](https://en.wikipedia.org/wiki/Robert_C._Martin)'s dependency management metrics for packages in [Pharo](https://pharo.org/).

DMMetrics is written and supported by Rafael Luque and other developers at [OSOCO](https://osoco.es).

## Description

DMMetrics computes the following metrics for your Smalltalk packages:

- **Stability metrics**:
  - *Afferent Couplings* (Ca): The number of classes outside a given package that depend on classes within that package.
  - *Efferent Couplings* (Ce): The number of classes inside a given package that depend on classes outside that package.
  - *Instability* (I): ![equation](docs/instability_equation.png)

- **Abstraction metrics**:
  - *Number of classes* (Nc): The number of classes in the package.
  - *Number of abstract classes* (Na): The number of abstract classes in the package. An abstract class is a class with at least one abstract method.
  - *Abstractness* (A): ![equation](docs/abstractness_equation.png)

- **The Main Sequence**:
  - *Distance to the main sequence* (D): ![equation](docs/main_sequence_distance_equation.png)
  - *Normalized distance to the main sequence* (D'): ![equation](docs/normalized_main_sequence_distance_equation.png)

## Install DMMetrics

To install DMMetrics on your Pharo image you can just execute the following script:

```Smalltalk
    Metacello new
    	githubUser: 'luque' project: 'dm-metrics' commitish: 'master' path: 'src';
    	baseline: 'DMMetrics';
    	load
```

To add DMMetrics to your own project's baseline just add this:

```Smalltalk
    spec
    	baseline: 'DMMetrics'
    	with: [ spec repository: 'github://luque/dm-metrics:master/src' ]
```

Note that you can replace the #master by another branch as #development or a tag.

## Getting started

To compute the dependency metrics for a collection of packages you can execute the following in a Playground:

```Smalltalk
    packages := RPackageOrganizer default packages select: [:p | 'ProfStef*' match: p name].
    (DMMPackageGroupVisualizations onPackages: packages) build open
```

This code will show you an inspector on the `DMMPackageGroupVisualizations` with the following tabs:

**DM Metrics**

![Inspector on DMMPackageGroupVisualizations - DM Metrics Tab](docs/Inspector_DMMPackageGroupVisualizations_Metrics_Tab.png)

**Distances to Main Sequence**

![Inspector on DMMPackageGroupVisualizations - Distances to Main Sequence Tab](docs/Inspector_DMMPackageGroupVisualizations_MainSequence_Tab.png)

**Package Dependencies**

![Inspector on DMMPackageGroupVisualizations - Package Dependencies Tab](docs/Inspector_DMMPackageVisualizations_Graph_Tab.png)