Improved permalinks for pages and collections

This updates the default permalink style for pages and collections to
match the site-wide 'permalink' setting.  If the permalink setting
contains a trailing slash, either explicitly or by being set to
':pretty', then pages and collections permalinks will contain trailing
slashes by default as well.  Similarly, if the permalink setting
contains a trailing ':output_ext', so will pages and collections.  If
the permalink setting contains neither a trailing slash or extension,
neither will pages or collections.

This impacts only the default permalink structure for pages and
collections.  Permalinks set in the frontmatter of an individual page
take precedence, as does the permalink setting for a specific
collection.

Fixes #2691

lib/jekyll/collection.rb

@@ -170,7 +170,9 @@ module Jekyll
     #
     # Returns the URL template to render collection's documents at.
     def url_template
-      metadata.fetch('permalink', "/:collection/:path:output_ext")
+      metadata.fetch('permalink') do
+          Utils.add_permalink_suffix("/:collection/:path", site.permalink_style)
+      end
     end
 
     # Extract options for this collection from the site configuration.

lib/jekyll/page.rb

@@ -63,16 +63,12 @@ module Jekyll
     #
     # Returns the template String.
     def template
-      if site.permalink_style == :pretty
-        if index? && html?
-          "/:path/"
-        elsif html?
-          "/:path/:basename/"
-        else
-          "/:path/:basename:output_ext"
-        end
-      else
+      if !html?
         "/:path/:basename:output_ext"
+      elsif index?
+        "/:path/"
+      else
+        Utils.add_permalink_suffix("/:path/:basename", site.permalink_style)
       end
     end
 

lib/jekyll/utils.rb

@@ -158,5 +158,45 @@ module Jekyll
         downcase
     end
 
+    # Add an appropriate suffix to template so that it matches the specified
+    # permalink style.
+    #
+    # template - permalink template without trailing slash or file extension
+    # permalink_style - permalink style, either built-in or custom
+    #
+    # The returned permalink template will use the same ending style as
+    # specified in permalink_style.  For example, if permalink_style contains a
+    # trailing slash (or is :pretty, which indirectly has a trailing slash),
+    # then so will the returned template.  If permalink_style has a trailing
+    # ":output_ext" (or is :none, :date, or :ordinal) then so will the returned
+    # template.  Otherwise, template will be returned without modification.
+    #
+    # Examples:
+    #   add_permalink_suffix("/:basename", :pretty)
+    #   # => "/:basename/"
+    #
+    #   add_permalink_suffix("/:basename", :date)
+    #   # => "/:basename:output_ext"
+    #
+    #   add_permalink_suffix("/:basename", "/:year/:month/:title/")
+    #   # => "/:basename/"
+    #
+    #   add_permalink_suffix("/:basename", "/:year/:month/:title")
+    #   # => "/:basename"
+    #
+    # Returns the updated permalink template
+    def add_permalink_suffix(template, permalink_style)
+      case permalink_style
+      when :pretty
+        template << "/"
+      when :date, :ordinal, :none
+        template << ":output_ext"
+      else
+        template << "/" if permalink_style.to_s.end_with?("/")
+        template << ":output_ext" if permalink_style.to_s.end_with?(":output_ext")
+      end
+      template
+    end
+
   end
 end

test/test_document.rb

@@ -219,7 +219,31 @@ class TestDocument < JekyllUnitTest
       assert_equal "/slides/test/example-slide-1", @document.url
     end
 
-    should "produce the right destination" do
+    should "produce the right destination file" do
+      assert_equal @dest_file, @document.destination(dest_dir)
+    end
+  end
+
+  context "a document in a collection with pretty permalink style" do
+    setup do
+      @site = fixture_site({
+        "collections" => {
+          "slides" => {
+            "output"    => true,
+          }
+        },
+      })
+      @site.permalink_style = :pretty
+      @site.process
+      @document = @site.collections["slides"].docs[0]
+      @dest_file = dest_dir("slides/example-slide-1/index.html")
+    end
+
+    should "produce the right URL" do
+      assert_equal "/slides/example-slide-1/", @document.url
+    end
+
+    should "produce the right destination file" do
       assert_equal @dest_file, @document.destination(dest_dir)
     end
   end

test/test_page.rb

@@ -46,7 +46,7 @@ class TestPage < JekyllUnitTest
 
         should "create index url based on filename" do
           @page = setup_page('/contacts', 'index.html')
-          assert_equal "/contacts/index.html", @page.url
+          assert_equal "/contacts/", @page.url
         end
       end
 
@@ -129,6 +129,58 @@ class TestPage < JekyllUnitTest
         end
       end
 
+      context "with date permalink style" do
+        setup do
+          @site.permalink_style = :date
+        end
+
+        should "return url and destination correctly" do
+          @page = setup_page('contacts.html')
+          @dest_file = dest_dir("contacts.html")
+          assert_equal '/contacts.html', @page.url
+          assert_equal @dest_file, @page.destination(dest_dir)
+        end
+      end
+
+      context "with custom permalink style with trailing slash" do
+        setup do
+          @site.permalink_style = "/:title/"
+        end
+
+        should "return url and destination correctly" do
+          @page = setup_page('contacts.html')
+          @dest_file = dest_dir("contacts/index.html")
+          assert_equal '/contacts/', @page.url
+          assert_equal @dest_file, @page.destination(dest_dir)
+        end
+      end
+
+      context "with custom permalink style with file extension" do
+        setup do
+          @site.permalink_style = "/:title:output_ext"
+        end
+
+        should "return url and destination correctly" do
+          @page = setup_page('contacts.html')
+          @dest_file = dest_dir("contacts.html")
+          assert_equal '/contacts.html', @page.url
+          assert_equal @dest_file, @page.destination(dest_dir)
+        end
+      end
+
+      context "with custom permalink style with no extension" do
+        setup do
+          @site.permalink_style = "/:title"
+        end
+
+        should "return url and destination correctly" do
+          @page = setup_page('contacts.html')
+          @dest_file = dest_dir("contacts.html")
+          assert_equal '/contacts', @page.url
+          assert_equal @dest_file, @page.destination(dest_dir)
+        end
+      end
+
       context "with any other permalink style" do
         should "return dir correctly" do
           @site.permalink_style = nil

test/test_utils.rb

@@ -166,4 +166,18 @@ class TestUtils < JekyllUnitTest
     end
   end
 
+  context "The \`Utils.add_permalink_suffix\` method" do
+    should "handle built-in permalink styles" do
+      assert_equal "/:basename/", Utils.add_permalink_suffix("/:basename", :pretty)
+      assert_equal "/:basename:output_ext", Utils.add_permalink_suffix("/:basename", :date)
+      assert_equal "/:basename:output_ext", Utils.add_permalink_suffix("/:basename", :ordinal)
+      assert_equal "/:basename:output_ext", Utils.add_permalink_suffix("/:basename", :none)
+    end
+
+    should "handle custom permalink styles" do
+      assert_equal "/:basename/", Utils.add_permalink_suffix("/:basename", "/:title/")
+      assert_equal "/:basename:output_ext", Utils.add_permalink_suffix("/:basename", "/:title:output_ext")
+      assert_equal "/:basename", Utils.add_permalink_suffix("/:basename", "/:title")
+    end
+  end
 end