Refactoring out LayoutParser

lib/squib/deck.rb

@@ -5,6 +5,7 @@ require 'squib/card'
 require 'squib/progress'
 require 'squib/input_helpers'
 require 'squib/constants'
+require 'squib/layout_parser'
 
 # The project module
 #
@@ -65,7 +66,7 @@ module Squib
       cards.times{ @cards << Squib::Card.new(self, width, height) }
       show_info(config, layout)
       load_config(config)
-      load_layout(layout)
+      @layout = LayoutParser.load_layout(layout)
       if block_given?
         instance_eval(&block)
       end
@@ -106,69 +107,6 @@ module Squib
       end
     end
 
-    # Load the layout configuration file, if exists
-    # @api private
-    def load_layout(files)
-      @layout = {}
-      Squib::logger.info { "  using layout(s): #{files}" }
-      Array(files).each do |file|
-        thefile = file
-        thefile = "#{File.dirname(__FILE__)}/layouts/#{file}" unless File.exists?(file)
-        if File.exists? thefile
-          yml = @layout.merge(YAML.load_file(thefile) || {}) #load_file returns false on empty file
-          yml.each do |key, value|
-            @layout[key] = recurse_extends(yml, key, {})
-          end
-        else
-          puts "the file: #{thefile}"
-          Squib::logger.error { "Layout file not found: #{file}" }
-        end
-      end
-    end
-
-    # Process the extends recursively
-    # :nodoc:
-    # @api private
-    def recurse_extends(yml, key, visited )
-      assert_not_visited(key, visited)
-      return yml[key] unless has_extends?(yml, key)
-      visited[key] = key
-      parent_keys = [yml[key]['extends']].flatten
-      h = {}
-      parent_keys.each do |parent_key|
-        from_extends = yml[key].merge(recurse_extends(yml, parent_key, visited)) do |key, child_val, parent_val|
-          if child_val.to_s.strip.start_with?('+=')
-            parent_val + child_val.sub('+=','').strip.to_f
-          elsif child_val.to_s.strip.start_with?('-=')
-            parent_val - child_val.sub('-=','').strip.to_f
-          else
-            child_val #child overrides parent when merging, no +=
-          end
-        end
-        h = h.merge(from_extends) do |key, older_sibling, younger_sibling|
-          younger_sibling #when two siblings have the same entry, the "younger" (lower one) overrides
-        end
-      end
-      return h
-    end
-
-    # Does this layout entry have an extends field?
-    # i.e. is it a base-case or will it need recursion?
-    # :nodoc:
-    # @api private
-    def has_extends?(yml, key)
-      !!yml[key] && yml[key].key?('extends')
-    end
-
-    # Safeguard against malformed circular extends
-    # :nodoc:
-    # @api private
-    def assert_not_visited(key, visited)
-      if visited.key? key
-        raise "Invalid layout: circular extends with '#{key}'"
-      end
-    end
-
     # Use Logger to show more detail on the run
     # :nodoc:
     # @api private

lib/squib/layout_parser.rb

@@ -0,0 +1,75 @@
+module Squib
+  # Internal class for handling layouts
+  #@api private
+  class LayoutParser
+
+    # Load the layout file(s), if exists
+    # @api private
+    def self.load_layout(files)
+      layout = {}
+      Squib::logger.info { "  using layout(s): #{files}" }
+      Array(files).each do |file|
+        thefile = file
+        thefile = builtin(file) unless File.exists?(file)
+        if File.exists? thefile
+          yml = layout.merge(YAML.load_file(thefile) || {}) #load_file returns false on empty file
+          yml.each do |key, value|
+            layout[key] = recurse_extends(yml, key, {})
+          end
+        else
+          Squib::logger.error { "Layout file not found: #{file}. Skipping..." }
+        end
+      end
+      return layout
+    end
+
+    # Determine the file path of the built-in layout file
+    def self.builtin(file)
+      "#{File.dirname(__FILE__)}/layouts/#{file}"
+    end
+
+    # Process the extends recursively
+    # :nodoc:
+    # @api private
+    def self.recurse_extends(yml, key, visited )
+      assert_not_visited(key, visited)
+      return yml[key] unless has_extends?(yml, key)
+      visited[key] = key
+      parent_keys = [yml[key]['extends']].flatten
+      h = {}
+      parent_keys.each do |parent_key|
+        from_extends = yml[key].merge(recurse_extends(yml, parent_key, visited)) do |key, child_val, parent_val|
+          if child_val.to_s.strip.start_with?('+=')
+            parent_val + child_val.sub('+=','').strip.to_f
+          elsif child_val.to_s.strip.start_with?('-=')
+            parent_val - child_val.sub('-=','').strip.to_f
+          else
+            child_val #child overrides parent when merging, no +=
+          end
+        end
+        h = h.merge(from_extends) do |key, older_sibling, younger_sibling|
+          younger_sibling #when two siblings have the same entry, the "younger" (lower one) overrides
+        end
+      end
+      return h
+    end
+
+    # Does this layout entry have an extends field?
+    # i.e. is it a base-case or will it need recursion?
+    # :nodoc:
+    # @api private
+    def self.has_extends?(yml, key)
+      !!yml[key] && yml[key].key?('extends')
+    end
+
+    # Safeguard against malformed circular extends
+    # :nodoc:
+    # @api private
+    def self.assert_not_visited(key, visited)
+      if visited.key? key
+        raise "Invalid layout: circular extends with '#{key}'"
+      end
+    end
+
+  end
+end

spec/deck_spec.rb

@@ -45,180 +45,16 @@ describe Squib::Deck do
     end
   end
 
-  context '#load_layout' do
-
   it 'loads a normal layout with no extends' do
     d = Squib::Deck.new(layout: layout_file('no-extends.yml'))
-      expect(d.layout).to \
+    expect(d.layout).to eq({
-        eq({'frame' => {
+      'frame' => {
         'x' => 38,
         'valign' => :middle,
         'str' => 'blah',
         'font' => 'Mr. Font',
       }
-            }
-          )
-    end
-
-    it 'loads with a single extends' do
-      d = Squib::Deck.new(layout: layout_file('single-extends.yml'))
-      expect(d.layout).to \
-        eq({'frame' => {
-              'x' => 38,
-              'y' => 38,
-              },
-            'title' => {
-              'extends' => 'frame',
-              'x' => 38,
-              'y' => 50,
-              'width' => 100,
-              }
-            }
-          )
-    end
-
-    it 'applies the extends regardless of order' do
-      d = Squib::Deck.new(layout: layout_file('pre-extends.yml'))
-      expect(d.layout).to \
-        eq({'frame' => {
-              'x' => 38,
-              'y' => 38,
-              },
-            'title' => {
-              'extends' => 'frame',
-              'x' => 38,
-              'y' => 50,
-              'width' => 100,
-              }
-            }
-          )
-    end
-
-    it 'applies the single-level extends multiple times' do
-      d = Squib::Deck.new(layout: layout_file('single-level-multi-extends.yml'))
-      expect(d.layout).to \
-        eq({'frame' => {
-              'x' => 38,
-              'y' => 38,
-              },
-            'title' => {
-              'extends' => 'frame',
-              'x' => 38,
-              'y' => 50,
-              'width' => 100,
-              },
-            'title2' => {
-              'extends' => 'frame',
-              'x' => 75,
-              'y' => 150,
-              'width' => 150,
-              },
-            }
-          )
-    end
-
-    it 'applies multiple extends in a single rule' do
-      d = Squib::Deck.new(layout: layout_file('multi-extends-single-entry.yml'))
-      expect(d.layout).to \
-        eq({'aunt' => {
-              'a' => 101,
-              'b' => 102,
-              'c' => 103,
-              },
-            'uncle' => {
-              'x' => 104,
-              'y' => 105,
-              'b' => 106,
-              },
-            'child' => {
-              'extends' => ['uncle','aunt'],
-              'a' => 107, # my own
-              'b' => 102, # from the younger aunt
-              'c' => 103, # from aunt
-              'x' => 108, # my own
-              'y' => 105, # from uncle
-              },
-            }
-          )
-    end
-
-    it 'applies multi-level extends' do
-      d = Squib::Deck.new(layout: layout_file('multi-level-extends.yml'))
-      expect(d.layout).to \
-        eq({'frame' => {
-              'x' => 38,
-              'y' => 38,
-              },
-            'title' => {
-              'extends' => 'frame',
-              'x' => 38,
-              'y' => 50,
-              'width' => 100,
-              },
-            'subtitle' => {
-              'extends' => 'title',
-              'x' => 38,
-              'y' => 150,
-              'width' => 100,
-              },
-            }
-          )
-    end
-
-    it 'fails on a self-circular extends' do
-      file = layout_file('self-circular-extends.yml')
-      expect { Squib::Deck.new(layout: file) }.to \
-        raise_error(RuntimeError, 'Invalid layout: circular extends with \'a\'')
-    end
-
-    it 'fails on a easy-circular extends' do
-      file = layout_file('easy-circular-extends.yml')
-      expect { Squib::Deck.new(layout: file) }.to \
-        raise_error(RuntimeError, 'Invalid layout: circular extends with \'a\'')
-    end
-
-    it 'hard on a easy-circular extends' do
-      file = layout_file('hard-circular-extends.yml')
-      expect { Squib::Deck.new(layout: file) }.to \
-        raise_error(RuntimeError, 'Invalid layout: circular extends with \'a\'')
-    end
-
-    it 'redefines keys on multiple layouts' do
-      a = layout_file('multifile-a.yml')
-      b = layout_file('multifile-b.yml')
-      d = Squib::Deck.new(layout: [a, b])
-      expect(d.layout).to eq({
-          'title'    => { 'x' => 300 },
-          'subtitle' => { 'x' => 200 }, 
-          'desc'     => { 'x' => 400 }
-          })
-    end
-
-    it 'evaluates extends on each file first' do
-      a = layout_file('multifile-extends-a.yml')
-      b = layout_file('multifile-extends-b.yml')
-      d = Squib::Deck.new(layout: [a, b])
-      expect(d.layout).to eq({
-          'grandparent' => { 'x' => 100 },
-          'parent_a'    => { 'x' => 110, 'extends' => 'grandparent' }, 
-          'parent_b'    => { 'x' => 130, 'extends' => 'grandparent' },
-          'child_a'     => { 'x' => 113, 'extends' => 'parent_a' },
-          'child_b'     => { 'x' => 133, 'extends' => 'parent_b' }
-          })
-    end
-
-    it 'loads nothing on an empty layout file' do
-      d = Squib::Deck.new(layout: layout_file('empty.yml'))
-      expect(d.layout).to eq({})
-    end
-
-    it 'handles extends on a rule with no args' do
-      d = Squib::Deck.new(layout: layout_file('empty-rule.yml'))
-      expect(d.layout).to eq({
-        'empty' => nil
     })
   end
 
 end
-
-end

spec/layout_parser_spec.rb

@@ -0,0 +1,176 @@
+require 'spec_helper'
+
+describe Squib::LayoutParser do
+
+  it 'loads a normal layout with no extends' do
+    layout = Squib::LayoutParser.load_layout(layout_file('no-extends.yml'))
+    expect(layout).to eq({'frame' => {
+            'x' => 38,
+            'valign' => :middle,
+            'str' => 'blah',
+            'font' => 'Mr. Font',
+            }
+          }
+        )
+  end
+
+  it 'loads with a single extends' do
+    layout = Squib::LayoutParser.load_layout(layout_file('single-extends.yml'))
+    expect(layout).to eq({'frame' => {
+            'x' => 38,
+            'y' => 38,
+            },
+          'title' => {
+            'extends' => 'frame',
+            'x' => 38,
+            'y' => 50,
+            'width' => 100,
+            }
+          }
+        )
+  end
+
+  it 'applies the extends regardless of order' do
+    layout = Squib::LayoutParser.load_layout(layout_file('pre-extends.yml'))
+    expect(layout).to eq({'frame' => {
+            'x' => 38,
+            'y' => 38,
+            },
+          'title' => {
+            'extends' => 'frame',
+            'x' => 38,
+            'y' => 50,
+            'width' => 100,
+            }
+          }
+        )
+  end
+
+  it 'applies the single-level extends multiple times' do
+    layout = Squib::LayoutParser.load_layout(layout_file('single-level-multi-extends.yml'))
+    expect(layout).to eq({'frame' => {
+            'x' => 38,
+            'y' => 38,
+            },
+          'title' => {
+            'extends' => 'frame',
+            'x' => 38,
+            'y' => 50,
+            'width' => 100,
+            },
+          'title2' => {
+            'extends' => 'frame',
+            'x' => 75,
+            'y' => 150,
+            'width' => 150,
+            },
+          }
+        )
+  end
+
+  it 'applies multiple extends in a single rule' do
+    layout = Squib::LayoutParser.load_layout(layout_file('multi-extends-single-entry.yml'))
+    expect(layout).to eq({'aunt' => {
+            'a' => 101,
+            'b' => 102,
+            'c' => 103,
+            },
+          'uncle' => {
+            'x' => 104,
+            'y' => 105,
+            'b' => 106,
+            },
+          'child' => {
+            'extends' => ['uncle','aunt'],
+            'a' => 107, # my own
+            'b' => 102, # from the younger aunt
+            'c' => 103, # from aunt
+            'x' => 108, # my own
+            'y' => 105, # from uncle
+            },
+          }
+        )
+  end
+
+  it 'applies multi-level extends' do
+    layout = Squib::LayoutParser.load_layout(layout_file('multi-level-extends.yml'))
+    expect(layout).to eq({'frame' => {
+            'x' => 38,
+            'y' => 38,
+            },
+          'title' => {
+            'extends' => 'frame',
+            'x' => 38,
+            'y' => 50,
+            'width' => 100,
+            },
+          'subtitle' => {
+            'extends' => 'title',
+            'x' => 38,
+            'y' => 150,
+            'width' => 100,
+            },
+          }
+        )
+  end
+
+  it 'fails on a self-circular extends' do
+    file = layout_file('self-circular-extends.yml')
+    expect { Squib::LayoutParser.load_layout(file) }
+      .to raise_error(RuntimeError, 'Invalid layout: circular extends with \'a\'')
+  end
+
+  it 'fails on a easy-circular extends' do
+    file = layout_file('easy-circular-extends.yml')
+    expect { Squib::LayoutParser.load_layout(file) }
+      .to raise_error(RuntimeError, 'Invalid layout: circular extends with \'a\'')
+  end
+
+  it 'hard on a easy-circular extends' do
+    file = layout_file('hard-circular-extends.yml')
+    expect { Squib::LayoutParser.load_layout(file) }
+      .to raise_error(RuntimeError, 'Invalid layout: circular extends with \'a\'')
+  end
+
+  it 'redefines keys on multiple layouts' do
+    a = layout_file('multifile-a.yml')
+    b = layout_file('multifile-b.yml')
+    layout = Squib::LayoutParser.load_layout([a, b])
+    expect(layout).to eq({
+        'title'    => { 'x' => 300 },
+        'subtitle' => { 'x' => 200 },
+        'desc'     => { 'x' => 400 }
+        })
+  end
+
+  it 'evaluates extends on each file first' do
+    a = layout_file('multifile-extends-a.yml')
+    b = layout_file('multifile-extends-b.yml')
+    layout = Squib::LayoutParser.load_layout([a, b])
+    expect(layout).to eq({
+        'grandparent' => { 'x' => 100 },
+        'parent_a'    => { 'x' => 110, 'extends' => 'grandparent' },
+        'parent_b'    => { 'x' => 130, 'extends' => 'grandparent' },
+        'child_a'     => { 'x' => 113, 'extends' => 'parent_a' },
+        'child_b'     => { 'x' => 133, 'extends' => 'parent_b' }
+        })
+  end
+
+  it 'loads nothing on an empty layout file' do
+    layout = Squib::LayoutParser.load_layout(layout_file('empty.yml'))
+    expect(layout).to eq({})
+  end
+
+  it 'handles extends on a rule with no args' do
+    layout = Squib::LayoutParser.load_layout(layout_file('empty-rule.yml'))
+    expect(layout).to eq({
+      'empty' => nil
+    })
+  end
+
+  it 'logs an error when a file is not found' do
+    expect(Squib.logger).to receive(:error).once
+    Squib::LayoutParser.load_layout('yeti')
+  end
+
+end