add link to function source

hardcoded to elixir github repo for now

lib/exdoc.ex

@@ -67,7 +67,7 @@ defmodule ExDoc do
     Erlang.file.write_file("#{output_path}/index.html", content)
   end
 
-  defp get_names({ module_name, { _, functions }}) do
+  defp get_names({ module_name, _, { _, functions }}) do
     functions = Enum.map functions, get_function_name(&1)
     { module_name, functions }
   end

lib/exdoc/html_formatter.ex

@@ -1,6 +1,6 @@
 defmodule ExDoc.HTMLFormatter do
-  def format_docs({name,{ moduledoc, docs }}, output_path) do
-    docs = generate_html_for_docs(docs)
+  def format_docs({name, source_path, { moduledoc, docs }}, output_path) do
+    docs = generate_html_for_docs(source_path, docs)
     moduledoc = generate_html_for_moduledoc(moduledoc)
     function_docs = Enum.filter_map docs, fn(x, do: filter_by_type(x, :def)), fn(x, do: get_content(x))
     macro_docs = Enum.filter_map docs, fn(x, do: filter_by_type(x, :defmacro)), fn(x, do: get_content(x))
@@ -33,15 +33,16 @@ defmodule ExDoc.HTMLFormatter do
     Markdown.to_html(doc)
   end
 
-  defp generate_html_for_docs(docs) do
-    Enum.map docs, extract_docs(&1)
+  defp generate_html_for_docs(source_path, docs) do
+    Enum.map docs, extract_docs(source_path, &1)
   end
 
-  defp extract_docs({ { name, arity }, _line, type, doc }) do
+  defp extract_docs(source_path, { { name, arity }, line, type, doc }) do
     html = if doc, do: Markdown.to_html(doc), else: ""
 
     function_name = "#{name}/#{arity}"
-    content = %b{<div class="function"><div class="function-title" id="#{function_name}">\n<b>#{function_name}</b>\n</div>\n<div class="description">\n#{html}</div>\n</div>\n}
+    source_link = %b{<a href="https://github.com/elixir-lang/elixir/blob/master/#{source_path}#L#{line}" target="_blank">Source</a>}
+    content = %b{<div class="function"><div class="function-title" id="#{function_name}">\n<b>#{function_name}</b>\n</div>\n<div class="description">\n#{html}</div>\n#{source_link}</div>\n}
     { type, content }
   end
 

lib/exdoc/retriever.ex

@@ -12,7 +12,7 @@ defmodule ExDoc.Retriever do
     moduledoc = module.__info__(:moduledoc)
     docs = Enum.filter module.__info__(:docs), has_doc?(&1)
 
-    { module_name, { moduledoc, docs } }
+    { module_name, source_path(module), { moduledoc, docs } }
   end
 
   defp has_doc?({_, _, _, false}) do
@@ -33,4 +33,13 @@ defmodule ExDoc.Retriever do
     hierarchy = :lists.subtract name, relative
     Enum.join hierarchy, "."
   end
+
+  defp source_path(module) do
+    compile_info = module.__info__(:compile)
+    compile_options = :proplists.get_value :options, compile_info
+    compile_source  = :proplists.get_value :source,  compile_info
+
+    list_to_binary :lists.nthtail(length(compile_source) + 1,
+                                  :proplists.get_value(:source, compile_options))
+  end
 end

test/exdoc/html_formatter_test.exs

@@ -15,8 +15,12 @@ defmodule ExDoc.HTMLFormatterTest do
     File.expand_path "test/tmp/output"
   end
 
+  defp source_root_url do
+    "https://github.com/elixir-lang/elixir/blob/master/"
+  end
+
   test "format_docs generate only the module name when there's no more info" do
-    ExDoc.HTMLFormatter.format_docs({"XPTOModule", {{1, nil}, []}}, output_dir)
+    ExDoc.HTMLFormatter.format_docs({"XPTOModule", "", {{1, nil}, []}}, output_dir)
 
     content = File.read!("#{output_dir}/XPTOModule.html")
     assert Regex.match?(%r/<title>XPTOModule<\/title>/, content)
@@ -39,5 +43,6 @@ defmodule ExDoc.HTMLFormatterTest do
     assert Regex.match?(%r/example\/0.*Some example/m, content)
     assert Regex.match?(%r/example_without_docs\/0.*<div class="description">.*<\/div>/m, content)
     assert Regex.match?(%r/example_1\/0.*Another example/m, content)
+    assert Regex.match?(%r{<a href="#{source_root_url}test/fixtures/compiled_with_docs.ex#L10"[^>]*>Source<\/a>}m, content)
   end
 end

test/exdoc/retriever_test.exs

@@ -12,35 +12,35 @@ defmodule ExDoc.RetrieverTest do
   test "get_docs returns the module name" do
     file = "#{input_path}/__MAIN__/CompiledWithDocs.beam"
 
-    assert_match [{ "CompiledWithDocs", _ }], R.get_docs([file], input_path)
+    assert_match [{ "CompiledWithDocs", _, _ }], R.get_docs([file], input_path)
   end
 
   test "get_docs returns the nested module name" do
     file = "#{input_path}/__MAIN__/ExDocTest/Nested.beam"
 
-    assert_match [{ "ExDocTest.Nested", _ }], R.get_docs([file], input_path)
+    assert_match [{ "ExDocTest.Nested", _, _ }], R.get_docs([file], input_path)
   end
 
   test "get_docs returns the moduledoc info" do
     file = "#{input_path}/__MAIN__/CompiledWithDocs.beam"
 
-    [{ _, {moduledoc, _} }] = R.get_docs([file], input_path)
+    [{ _, _, {moduledoc, _} }] = R.get_docs([file], input_path)
 
     assert_match { 1, "moduledoc\n\n\#\# Example\n    CompiledWithDocs.example\n" }, moduledoc
   end
 
   test "get_docs returns nil if there's no moduledoc info" do
     file = "#{input_path}/__MAIN__/CompiledWithoutDocs.beam"
 
-    [{ _, {moduledoc, _} }] = R.get_docs([file], input_path)
+    [{ _, _, {moduledoc, _} }] = R.get_docs([file], input_path)
 
     assert_match { _, nil }, moduledoc
   end
 
   test "get_docs returns the doc info for each module function" do
     file = "#{input_path}/__MAIN__/CompiledWithDocs.beam"
 
-    [{ _, {_, doc} }] = R.get_docs([file], input_path)
+    [{ _, _, {_, doc} }] = R.get_docs([file], input_path)
 
     assert_match [
       {{:example, 0}, 10, :def, "Some example"},
@@ -52,8 +52,16 @@ defmodule ExDoc.RetrieverTest do
   test "get_docs returns an empty list if there's no docs info" do
     file = "#{input_path}/__MAIN__/CompiledWithoutDocs.beam"
 
-    [{ _, {_, doc} }] = R.get_docs([file], input_path)
+    [{ _, _, {_, doc} }] = R.get_docs([file], input_path)
 
     assert_empty doc
   end
+
+  test "get_docs returns a relative source path" do
+    file = "#{input_path}/__MAIN__/CompiledWithDocs.beam"
+
+    [{ _, path, _ }] = R.get_docs([file], input_path)
+
+    assert path == "test/fixtures/compiled_with_docs.ex"
+  end
 end