## Table of Contents

* [Scope](#scope)
  * [Alternatives](#alternatives)
    * [gem dep](#gem-dep)
    * [bundle viz](#bundle-viz)
* [Usage](#usage)
  * [Warning](#warning)
  * [Unique dependencies](#unique-dependencies)
  * [Recursive print](#recursive-print)
  * [Filter by version](#filter-by-version)

## Scope
This gem is aimed to list recursively the **runtime dependencies** footprint of the specified gem.

### Alternatives
Some alternatives exists: 

#### gem dep
The standard *gem dep* command just unearth one level of dependencies.

#### bundle viz
The *bundle viz* command relies on the Gemfile and the [graphviz](http://www.graphviz.org/) library to generate a visual representation of the gem inter-dependencies.  
While it is great to visualize inter-dependencies, i have hard times figuring out gem's  runtime footprint.

## Usage
The library relies on the *Gem::Commands::DependencyCommand* class (the one invoked by the *gem dep* command line), invoking it recursively to deeply fetch dependencies.

### Warning
Consider only the gems installed on your system are scanned for their own dependencies, no remote fetching is performed.

### Unique dependencies
The command outcome includes all of the unique (by name) nested runtime dependencies:
```
$ lapidarius --gem=grape

grape (0.17.0)              20
------------------------------
activesupport (>= 0)
builder (>= 0)
hashie (>= 2.1.0)
multi_json (>= 1.3.2)
multi_xml (>= 0.5.2)
mustermann19 (~> 0.4.3)
rack (>= 1.3.0)
rack-accept (>= 0)
virtus (>= 1.0.0)
concurrent-ruby (>= 1.0.2, ~> 1.0)
i18n (~> 0.7)
minitest (~> 5.1)
tzinfo (~> 1.1)
thread_safe (~> 0.1)
enumerable-lazy (>= 0)
axiom-types (~> 0.1)
coercible (~> 1.0)
descendants_tracker (>= 0.0.3, ~> 0.0)
equalizer (>= 0.0.9, ~> 0.0)
ice_nine (~> 0.11.0)

```

### Recursive print
To print dependencies hierarchy recursively, provide the *--recursive* flag. Duplicates are not counted:  
```
$ lapidarius --gem=sinatra --recursive

sinatra (1.4.7)              3
------------------------------
rack (~> 1.5)
rack-protection (~> 1.4)
  rack (>= 0)
tilt (< 3, >= 1.3)

```

### Filter by version
If you have multiple versions of the same gem installed, the library will fetch the first one listed by default.
To specify the version of the gem to be scanned provide the *--version* flag:
```
$ lapidarius --gem=rack --version=2.0.1

rack (2.0.1)                 0
------------------------------

```