Print source location consistently and using relative paths

Author: josevalim

lib/iex/lib/iex/introspection.ex

@@ -184,8 +184,8 @@ defmodule IEx.Introspection do
   """
   def source(module) when is_atom(module) do
     case source_location(module) do
-      {:ok, {file, _line}} ->
-        IO.puts(File.read!(file))
+      {:ok, {file, line}} ->
+        print_source(file, line)
 
       {:error, reason} ->
         puts_error("Could not show source for #{inspect(module)}, #{reason}")
@@ -196,8 +196,8 @@ defmodule IEx.Introspection do
 
   def source({module, function}) when is_atom(module) and is_atom(function) do
     case source_location({module, function}) do
-      {:ok, {file, _line}} ->
-        IO.puts(File.read!(file))
+      {:ok, {file, line}} ->
+        print_source(file, line)
 
       {:error, reason} ->
         puts_error("Could not show source for #{inspect(module)}.#{function}, #{reason}")
@@ -209,8 +209,8 @@ defmodule IEx.Introspection do
   def source({module, function, arity})
       when is_atom(module) and is_atom(function) and is_integer(arity) do
     case source_location({module, function, arity}) do
-      {:ok, {file, _line}} ->
-        IO.puts(File.read!(file))
+      {:ok, {file, line}} ->
+        print_source(file, line)
 
       {:error, reason} ->
         puts_error("Could not show source for #{inspect(module)}.#{function}/#{arity}, #{reason}")
@@ -224,6 +224,10 @@ defmodule IEx.Introspection do
     dont_display_result()
   end
 
+  defp print_source(file, line) do
+    IO.puts(Path.relative_to_cwd(file) <> ":" <> Integer.to_string(line))
+  end
+
   @doc """
   Returns the source location for the given module, {module, function},
   or {module, function, arity}.

lib/iex/test/iex/helpers_test.exs

@@ -317,17 +317,21 @@ defmodule IEx.HelpersTest do
 
   describe "source" do
     @describetag :requires_source
+    @example_module_source "test/test_helper.exs"
 
-    test "prints source for Elixir module" do
-      assert capture_iex("source(HelperExampleModule)") =~ "defmodule HelperExampleModule"
+    test "prints source location for Elixir module" do
+      assert capture_iex("source(HelperExampleModule)") =~
+               ~r/#{@example_module_source}:\d+$/
     end
 
-    test "prints source for module.function" do
-      assert capture_iex("source(HelperExampleModule.fun)") =~ "defmodule HelperExampleModule"
+    test "prints source location for module.function" do
+      assert capture_iex("source(HelperExampleModule.fun)") =~
+               ~r/#{@example_module_source}:\d+$/
     end
 
-    test "prints source for module.function/arity" do
-      assert capture_iex("source(HelperExampleModule.fun/1)") =~ "defmodule HelperExampleModule"
+    test "prints source location for module.function/arity" do
+      assert capture_iex("source(HelperExampleModule.fun/1)") =~
+               ~r/#{@example_module_source}:\d+$/
     end
 
     test "errors if module is not available" do

lib/mix/lib/mix/tasks/source.ex

@@ -53,7 +53,7 @@ defmodule Mix.Tasks.Source do
                     {:error, message} -> Mix.raise(message)
                   end
                 else
-                  Mix.shell().info("#{file}:#{line}")
+                  Mix.shell().info("#{Path.relative_to_cwd(file)}:#{line}")
                 end
 
               {:error, reason} ->