units: support mm

Closes #161

CHANGELOG.md

@@ -1,6 +1,11 @@
 # Squib CHANGELOG
 Squib follows [semantic versioning](http://semver.org).
 
+## v0.11.0 / 2016-06-27
+
+Features:
+* Unit conversion supports mm (#161)
+
 ## v0.10.0 / 2016-05-06
 
 Features:

docs/dsl/mm.rst

@@ -0,0 +1,19 @@
+mm
+------
+
+Given millimeters, returns the number of pixels according to the deck's DPI.
+
+Parameters
+^^^^^^^^^^
+
+n
+  the number of mm
+
+
+Examples
+^^^^^^^^
+
+.. code-block:: ruby
+
+  mm(1)         # 11.811px (for default Deck::dpi of 300)
+  mm(2) + mm(1) # 35.433ox (for default Deck::dpi of 300)

docs/units.rst

@@ -1,6 +1,6 @@
 Unit Conversion
 ===============
 
-By default, Squib thinks in pixels. This decision was made so that we can have pixel-perfect layouts without automatically scaling everything, even though working in units is sometimes easier. We provide some conversion methods, including looking for strings that end in "in" and "cm" and computing based on the current DPI. The dpi is set on `Squib::Deck.new` (not `config.yml`).
+By default, Squib thinks in pixels. This decision was made so that we can have pixel-perfect layouts without automatically scaling everything, even though working in units is sometimes easier. We provide some conversion methods, including looking for strings that end in "in", "cm", or "mm" and computing based on the current DPI. The dpi is set on `Squib::Deck.new` (not `config.yml`).
 
 Example is in `samples/units.rb` found [here](https://github.com/andymeneely/squib/tree/master/samples/units.rb)

lib/squib/api/units.rb

@@ -13,5 +13,10 @@ module Squib
       @dpi * Squib::INCHES_IN_CM * n.to_f
     end
 
+    # DSL method. See http://squib.readthedocs.io
+    def mm(n)
+      @dpi * Squib::INCHES_IN_CM * n.to_f / 10.0
+    end
+
   end
 end

lib/squib/args/unit_conversion.rb

@@ -15,6 +15,8 @@ module Squib
           arg.rstrip[0..-2].to_f * dpi
         when /cm$/ # ends with "cm"
           arg.rstrip[0..-2].to_f * dpi * INCHES_IN_CM
+        when /mm$/ # ends with "mm"
+          arg.rstrip[0..-2].to_f * dpi * INCHES_IN_CM / 10.0
         else
           arg
         end

spec/api/api_units_spec.rb

@@ -0,0 +1,37 @@
+require 'spec_helper'
+
+describe Squib::Deck do
+
+  let(:deck) { Squib::Deck.new }
+
+  context '#in' do
+    it 'converts inches properly' do
+      expect(deck.inches(1)).to eq 300
+    end
+
+    it 'handles strings too' do
+      expect(deck.inches('1')).to eq 300
+    end
+  end
+
+  context '#cm' do
+    it 'converts inches properly' do
+      expect(deck.cm(1)).to eq 118.1102361
+    end
+
+    it 'handles strings too' do
+      expect(deck.cm('1')).to eq 118.1102361
+    end
+  end
+
+  context '#mm' do
+    it 'converts inches properly' do
+      expect(deck.mm(1)).to eq 11.81102361
+    end
+
+    it 'handles strings too' do
+      expect(deck.mm('1')).to eq 11.81102361
+    end
+  end
+
+end

spec/args/unit_conversion_spec.rb

@@ -15,8 +15,15 @@ describe Squib::Args::UnitConversion do
     expect(subject.parse('1 in')).to eq(300)
   end
 
-  it 'does cm'                      do
+  it 'does cm' do
     expect(subject.parse('1cm')).to eq(118.1102361)
+    expect(subject.parse('1cm  ')).to eq(118.1102361)
   end
 
+  it 'does mm' do
+    expect(subject.parse('1mm')).to eq(11.81102361)
+    expect(subject.parse('1mm  ')).to eq(11.81102361)
+  end
+
+
 end