add markdown link filter

see #30

features/filter.feature

@@ -71,3 +71,62 @@ Feature: BibTeX
     And the "_site/scholar.html" file should exist
     And I should not see "Programming Ruby" in "_site/scholar.html"
     And I should see "The Ruby Programming Language" in "_site/scholar.html"
+
+  @tags @urls
+  Scenario: URLs as text
+    Given I have a scholar configuration with:
+      | key    | value             |
+      | source | ./_bibliography   |
+    And I have a "_bibliography" directory
+    And I have a file "_bibliography/references.bib":
+      """
+      @book{pickaxe,
+        title     = {Programming Ruby 1.9: The Pragmatic Programmer's Guide},
+        author    = {Thomas, Dave and Fowler, Chad and Hunt, Andy},
+        year      = {2009},
+        edition   = 3,
+        publisher = {Pragmatic Bookshelf},
+        url       = {https://pragprog.com}
+      }
+      """
+    And I have a page "scholar.html":
+      """
+      ---
+      ---
+      {% bibliography %}
+      """
+    When I run jekyll
+    Then the _site directory should exist
+    And the "_site/scholar.html" file should exist
+    And I should see "from https://pragprog.com" in "_site/scholar.html"
+
+  @tags @urls
+  Scenario: URLs as Markdown links
+    Given I have a scholar configuration with:
+      | key    | value             |
+      | source | ./_bibliography   |
+    And I have the following BibTeX filters:
+      | latex    |
+      | markdown |
+    And I have a "_bibliography" directory
+    And I have a file "_bibliography/references.bib":
+      """
+      @book{pickaxe,
+        title     = {Programming Ruby 1.9: The Pragmatic Programmer's Guide},
+        author    = {Thomas, Dave and Fowler, Chad and Hunt, Andy},
+        year      = {2009},
+        edition   = 3,
+        publisher = {Pragmatic Bookshelf},
+        url       = {https://pragprog.com}
+      }
+      """
+    And I have a page "scholar.html":
+      """
+      ---
+      ---
+      {% bibliography %}
+      """
+    When I run jekyll
+    Then the _site directory should exist
+    And the "_site/scholar.html" file should exist
+    And I should see "from \[https://pragprog.com\]\(https://pragprog.com\)" in "_site/scholar.html"

features/step_definitions/jekyll_steps.rb

@@ -43,12 +43,18 @@
   assert File.directory?(dir)
 end
 
-Then(/^I should see "(.*)" in "(.*)"$/) do |text, file|
-  assert_match Regexp.new(text), File.open(file).readlines.join
+Then(/^I should see "(.*)" in "(.*)"$/) do |pattern, file|
+  text = File.open(file).readlines.join
+
+  assert_match Regexp.new(pattern), text,
+    "Pattern /#{pattern}/ not found in: #{text}"
 end
 
-Then(/^I should not see "(.*)" in "(.*)"$/) do |text, file|
-  assert !File.open(file).readlines.join.match(Regexp.new(text))
+Then(/^I should not see "(.*)" in "(.*)"$/) do |pattern, file|
+  text = File.open(file).readlines.join
+
+  assert !text.match(Regexp.new(pattern)),
+    "Did not exptect /#{pattern}/ in: #{text}"
 end
 
 

features/step_definitions/scholar_steps.rb

@@ -27,6 +27,15 @@
   end
 end
 
+Given(/^I have the following BibTeX filters:$/) do |table|
+  File.open('_config.yml', 'a') do |f|
+    f.write("  bibtex_filters:\n")
+    table.raw.flatten.each do |row|
+      f.write("    - #{row}\n")
+    end
+  end
+end
+
 Then(/^"(.*)" should come before "(.*)" in "(.*)"$/) do |p1, p2, file|
   data = File.open(file).readlines.join('')
 

lib/jekyll/scholar.rb

@@ -19,3 +19,5 @@
 require 'jekyll/scholar/tags/quote'
 require 'jekyll/scholar/tags/reference'
 require 'jekyll/scholar/generators/details'
+
+require 'jekyll/scholar/plugins/markdown_links'

lib/jekyll/scholar/plugins/markdown_links.rb

@@ -0,0 +1,14 @@
+# Contriubted by @mfenner
+# See https://github.com/inukshuk/jekyll-scholar/issues/30
+
+require 'uri'
+
+module Jekyll
+  class Scholar
+    class Markdown < BibTeX::Filter
+      def apply(value)
+        value.to_s.gsub(URI.regexp(['http','https','ftp'])) { |c| "[#{$&}](#{$&})" }
+      end
+    end
+  end
+end