Allow blocks to parse/to_html for custom behaviour

lib/vandamme/parser.rb

@@ -15,14 +15,21 @@ class Parser
     #   Defaults to /^#{0,3} ?([\w\d\.-]+\.[\w\d\.-]+[a-zA-Z0-9])(?: \/ (\w+ \d{1,2}(?:st|nd|rd|th)?,\s\d{4}|\d{4}-\d{2}-\d{2}|\w+))?\n?[=-]*/
     #   See http://tech-angels.github.com/vandamme/#changelogs-convention
     # * +format+ (optional):: One of "raw", "markdown", "rdoc"
-    #
+    # * +match_group+ (optional):: A number to say which match group to use as key
+    # * +custom_hash_filler+ (optional):: A Proc that receives a hash, the regex match and content
+    #   and should fill the hash with custom content (another hash)
     # 
     def initialize(options={})
+      if options[:match_group] && options[:custom_hash_filler]
+        raise ArgumentError, "only one of match_group or custom_hash_filler should be given"
+      end
+
       @changelog          = options.fetch :changelog
       regexp              = options[:version_header_exp] || DEFAULT_REGEXP
       @version_header_exp = regexp.is_a?(Regexp) ? regexp : Regexp.new(/#{regexp}/)
       @match_group        = options[:match_group] || 0
       @format             = options[:format] || :raw
+      @custom_hash_filler = options[:custom_hash_filler]
       @changelog_hash     = {}
     end
 
@@ -32,12 +39,20 @@ def initialize(options={})
     # Parse changelog file, filling +@changelog_hash+ with
     # versions as keys, and version changelog as content.
     #
+    # When a block is given, yield the changelog hash, match and content.
+    # It's up to the caller to fill the hash as they see fit.
+    #
     def parse
       @changelog.scan(@version_header_exp) do |match|
         version_content = $~.post_match
         changelog_scanner = StringScanner.new(version_content)
         changelog_scanner.scan_until(@version_header_exp)
-        @changelog_hash[match[@match_group]] = (changelog_scanner.pre_match || version_content).gsub(/(\A\n+|\n+\z)/, '')
+        content = (changelog_scanner.pre_match || version_content).gsub(/(\A\n+|\n+\z)/, '')
+        if @custom_hash_filler
+          @custom_hash_filler.call(@changelog_hash, match, content)
+        else
+          @changelog_hash[match[@match_group]] = content
+        end
       end
       @changelog_hash
     end
@@ -47,10 +62,18 @@ def parse
     # "rdoc", "md", 'markdown", "raw", etc.)
     # See https://github.com/github/markup/blob/master/lib/github/markups.rb
     # for more formats. The corresponding gem must be bundled.
+    #
+    # If the @changelog_hash is not just key -> String(content), a block must be provided
+    # that can get the string content from the custom content. For example,
+    # if the content is a hash like { date: '2017-09-19', content: '* Things' }, calling
+    # to_html { |hash| hash[:content] } will render "<ul><li>Things</li></ul>"
     def to_html
       self.parse if @changelog_hash.empty?
-      # GitHub Markup API is really weird, we MUST pass a file name for format detection as 1st arg:
-      @changelog_hash.inject({}) { |h,(k,v)| h[k] = GitHub::Markup.render(".#{@format}", v); h }
+      @changelog_hash.each_with_object({}) do |(k, v), h|
+        value = block_given? ? yield(v) : v
+        # GitHub Markup API is really weird, we MUST pass a file name for format detection as 1st arg:
+        h[k] = GitHub::Markup.render(".#{@format}", value)
+      end
     end
   end
 end

spec/vandamme/parser_spec.rb

@@ -1,6 +1,17 @@
 require 'spec_helper'
 
 describe Vandamme::Parser do
+  context "both match_group and custom_hash_filler are provided" do
+    it "raises an ArgumentError" do
+      expect {
+        Vandamme::Parser.new(
+          changelog: '',
+          match_group: 1,
+          custom_hash_filler: -> {}
+        )
+      }.to raise_error(ArgumentError, /only one of match_group or custom_hash_filler should be given/)
+    end
+  end
   context "with json gem changelog" do
     let(:changelog_file) { File.read("spec/fixtures/json.md") }
     let(:changelog_as_hash) {
@@ -178,22 +189,76 @@
       eos
       }
 
-    let(:changelog_as_hash) {
-      {
-        "X.Y.Z"           => "* Update API \n* Fix bug #1",
-        "1.2.3-pre.1"     => "* Update API ",
-        "1.0.0-x.7.z.92"  => ""
-      }
-    }
-
-
-    before do
-      @parser = Vandamme::Parser.new(changelog: changelog_file)
-      @changelog_parsed = @parser.parse
+    let(:hash_filler) { nil }
+    let(:parser) do
+      Vandamme::Parser.new(
+        changelog: changelog_file,
+        format: 'markdown',
+        custom_hash_filler: hash_filler
+      )
     end
 
-    it "should parse file and fill changelog hash" do
-      expect(@changelog_parsed).to eq(changelog_as_hash)
+    describe "#parse" do
+      subject(:parsed) { parser.parse }
+
+      context "no blocks are given" do
+        let(:changelog_as_hash) {
+          {
+            "X.Y.Z"           => "* Update API \n* Fix bug #1",
+            "1.2.3-pre.1"     => "* Update API ",
+            "1.0.0-x.7.z.92"  => ""
+          }
+        }
+        let(:changelog_as_html_hash) {
+          {
+            "X.Y.Z" => "<ul>\n<li>Update API</li>\n<li>Fix bug #1</li>\n</ul>\n",
+            "1.2.3-pre.1" => "<ul>\n<li>Update API</li>\n</ul>\n",
+            "1.0.0-x.7.z.92" => ""
+          }
+        }
+
+        it "should parse file and fill changelog hash" do
+          expect(parsed).to eq(changelog_as_hash)
+        end
+
+        it "renders to_html" do
+          expect(parser.to_html).to eq(changelog_as_html_hash)
+        end
+      end
+
+      context "blocks are given" do
+        let(:hash_filler) do
+          ->(result, header_match, content) do
+            result[header_match[0]] = { date: header_match[1], content: content }
+          end
+        end
+        let(:content_getter) do
+          ->(hash) { hash[:content] }
+        end
+        let(:changelog_as_hash) {
+          {
+            "X.Y.Z"           => { date: "Unreleased", content: "* Update API \n* Fix bug #1" },
+            "1.2.3-pre.1"     => { date: "2013-02-14", content: "* Update API "},
+            "1.0.0-x.7.z.92"  => { date: nil, content: ""},
+          }
+        }
+        let(:changelog_as_html_hash) {
+          {
+            "X.Y.Z" => "<ul>\n<li>Update API</li>\n<li>Fix bug #1</li>\n</ul>\n",
+            "1.2.3-pre.1" => "<ul>\n<li>Update API</li>\n</ul>\n",
+            "1.0.0-x.7.z.92" => ""
+          }
+        }
+
+        it "should parse file and fill custom changelog hash" do
+          expect(parsed).to eq(changelog_as_hash)
+        end
+
+        it "renders to_html" do
+          expect(parser.to_html(&content_getter)).to eq(changelog_as_html_hash)
+        end
+      end
     end
+
   end
 end