Add compact_output option

lib/earmark.ex

@@ -410,6 +410,10 @@ defmodule Earmark do
     Pure links of the form `~r{\\bhttps?://\\S+\\b}` are rendered as links from now on.
     However, by setting the `pure_links` option to `false` this can be disabled and pre 1.4
     behavior can be used.
+
+  * `compact_output`: boolean
+
+    If set to true, no cosmetic newlines will be emitted by Earmark. False by default.
   """
   def as_html(lines, options \\ %Options{})
 

lib/earmark/options.ex

@@ -35,7 +35,8 @@ defmodule Earmark.Options do
             line: 1,
             # [{:error|:warning, lnb, text},...]
             messages: [],
-            pure_links: true
+            pure_links: true,
+            compact_output: false
 
   @type t :: %__MODULE__{
         breaks: boolean,

lib/earmark/transform.ex

@@ -26,13 +26,16 @@ defmodule Earmark.Transform do
   end
 
 
+  defp maybe_add_newline(%{compact_output: true}), do: []
+  defp maybe_add_newline(_), do: ?\n
+
   defp to_html(ast, options) do
     _to_html(ast, options, Map.get(options, :initial_indent, 0))|> IO.iodata_to_binary
   end
 
   defp _to_html(ast, options, level, verbatim \\ false)
-  defp _to_html({:comment, _, content, _}, _options, _level, _verbatim) do
-    "<!--#{content |> Enum.intersperse("\n")}-->\n"
+  defp _to_html({:comment, _, content, _}, options, _level, _verbatim) do
+    ["<!--", Enum.intersperse(content, ?\n), "-->", maybe_add_newline(options)]
   end
   defp _to_html({"code", atts, children, meta}, options, level, _verbatim) do
     verbatim = meta |> Map.get(:verbatim, false)
@@ -44,10 +47,10 @@ defmodule Earmark.Transform do
     [open_tag(tag, atts),
        children
        |> Enum.map(&_to_html(&1, options, level, verbatim)),
-       "</#{tag}>"]
+       "</", tag, ?>]
   end
   defp _to_html({tag, atts, _, _}, options, level, _verbatim) when tag in @void_elements do
-    [ make_indent(options, level), open_tag(tag, atts), "\n" ]
+    [ make_indent(options, level), open_tag(tag, atts), maybe_add_newline(options) ]
   end
   defp _to_html(elements, options, level, verbatim) when is_list(elements) do
     elements
@@ -64,19 +67,19 @@ defmodule Earmark.Transform do
     [ make_indent(options, level),
       open_tag("pre", atts),
       _to_html(children, Map.put(options, :smartypants, false), level, verbatim),
-      "</pre>\n"]
+      "</pre>", maybe_add_newline(options)]
   end
   defp _to_html({tag, atts, children, meta}, options, level, _verbatim) do
     verbatim = meta |> Map.get(:verbatim, false)
     [ make_indent(options, level),
       open_tag(tag, atts),
-      "\n",
+      maybe_add_newline(options),
       _to_html(children, options, level+1, verbatim),
       close_tag(tag, options, level)]
   end
 
   defp close_tag(tag, options, level) do
-    [make_indent(options, level), "</", tag, ">\n"]
+    [make_indent(options, level), "</", tag, ?>, maybe_add_newline(options)]
   end
 
   defp escape(element, options)
@@ -101,10 +104,10 @@ defmodule Earmark.Transform do
 
   defp open_tag(tag, atts)
   defp open_tag(tag, atts) when tag in @void_elements do
-    ["<", "#{tag}", Enum.map(atts, &make_att(&1, tag)), " />"]
+    [?<, tag, Enum.map(atts, &make_att(&1, tag)), " />"]
   end
   defp open_tag(tag, atts) do
-    ["<", "#{tag}", Enum.map(atts, &make_att(&1, tag)), ">"]
+    [?<, tag, Enum.map(atts, &make_att(&1, tag)), ?>]
   end
 
   @em_dash_rgx ~r{---}

test/acceptance/html/compact_output_test.exs

@@ -0,0 +1,22 @@
+defmodule Acceptance.Html.CompactModeTest do
+  use Support.AcceptanceTestCase
+
+  describe "Compact output option" do
+    test "avoids creating newlines" do
+      markdown = "# h1\n## h2\n### h3\n\n**bold** text *italics*\n>blockquote\n1. list element\n2. list element \n\n `code` [link](http://example.com)"
+      {:ok, html, _} = as_html(markdown, compact_output: true)
+      refute html =~ "\n"
+    end
+   test "preserves newlines in code blocks" do
+     markdown = """
+                ```elixir
+                  Earmark.as_html!(markdown, compact_output: true)
+                  Earmark.as_html!(markdown, compact_output: false)
+                ```
+               """
+     expected = "<pre><code class=\"elixir\">   Earmark.as_html!(markdown, compact_output: true)\n   Earmark.as_html!(markdown, compact_output: false)</code></pre>"
+     {:ok, html, _} = as_html(markdown, compact_output: true)
+     assert html == expected
+   end
+  end
+end