From 13af842c66df48ddc804d42ba4777458276581df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonatan=20M=C3=A4nnchen?= <jonatan@maennchen.ch>
Date: Tue, 11 Jun 2019 23:50:41 +0200
Subject: [PATCH] IEx: Sort Types in `t` helper (#9131)

---
 lib/iex/lib/iex/introspection.ex  | 47 +++++++++++++++++++------------
 lib/iex/test/iex/helpers_test.exs | 14 +++++++++
 2 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/lib/iex/lib/iex/introspection.ex b/lib/iex/lib/iex/introspection.ex
index d054f92cb8..c48230081f 100644
--- a/lib/iex/lib/iex/introspection.ex
+++ b/lib/iex/lib/iex/introspection.ex
@@ -644,7 +644,9 @@ defmodule IEx.Introspection do
         types_not_found(inspect(module))
 
       {:ok, types} ->
-        Enum.each(types, &(&1 |> format_type() |> IO.puts()))
+        types
+        |> Enum.sort_by(fn {_, {name, _, args}} -> {name, length(args)} end)
+        |> Enum.each(&(&1 |> format_type() |> IO.puts()))
     end
 
     dont_display_result()
@@ -656,15 +658,19 @@ defmodule IEx.Introspection do
         no_beam(module)
 
       {:ok, types} ->
-        printed =
-          for {kind, {^type, _, args}} = typespec <- types,
-              kind != :typep do
-            type_doc(module, type, length(args), typespec)
-            |> print_typespec()
-          end
+        types
+        |> Enum.filter(&match?({kind, {^type, _, _}} when kind in [:type, :opaque], &1))
+        |> Enum.sort_by(fn {_, {name, _, args}} -> {name, length(args)} end)
+        |> case do
+          [] ->
+            types_not_found_or_private("#{inspect(module)}.#{type}")
 
-        if printed == [] do
-          types_not_found_or_private("#{inspect(module)}.#{type}")
+          types ->
+            Enum.map(types, fn {_, {_, _, args}} = typespec ->
+              module
+              |> type_doc(type, length(args), typespec)
+              |> print_typespec()
+            end)
         end
     end
 
@@ -677,16 +683,21 @@ defmodule IEx.Introspection do
         no_beam(module)
 
       {:ok, types} ->
-        printed =
-          for {kind, {^type, _, args}} = typespec <- types,
-              kind != :typep,
-              length(args) == arity do
-            type_doc(module, type, arity, typespec)
-            |> print_typespec()
-          end
+        types
+        |> Enum.find(
+          &match?(
+            {kind, {^type, _, args}} when kind in [:type, :opaque] and length(args) == arity,
+            &1
+          )
+        )
+        |> case do
+          nil ->
+            types_not_found_or_private("#{inspect(module)}.#{type}")
 
-        if printed == [] do
-          types_not_found_or_private("#{inspect(module)}.#{type}")
+          typespec ->
+            module
+            |> type_doc(type, arity, typespec)
+            |> print_typespec()
         end
     end
 
diff --git a/lib/iex/test/iex/helpers_test.exs b/lib/iex/test/iex/helpers_test.exs
index 77400bbfeb..0ac3a9c3d9 100644
--- a/lib/iex/test/iex/helpers_test.exs
+++ b/lib/iex/test/iex/helpers_test.exs
@@ -824,6 +824,10 @@ defmodule IEx.HelpersTest do
              end) >= 2
     end
 
+    test "prints private types" do
+      assert capture_io(fn -> t(Date.Range) end) =~ "@typep iso_days"
+    end
+
     test "prints type information" do
       assert "@type t() ::" <> _ = capture_io(fn -> t(Enum.t()) end)
       assert capture_io(fn -> t(Enum.t()) end) == capture_io(fn -> t(Enum.t() / 0) end)
@@ -831,6 +835,16 @@ defmodule IEx.HelpersTest do
       assert capture_io(fn -> t(URI.t()) end) == capture_io(fn -> t(URI.t() / 0) end)
     end
 
+    test "sorts types alphabetically" do
+      unsorted =
+        capture_io(fn -> t(Enum) end)
+        |> String.split("\n")
+        |> Enum.reject(&(&1 == ""))
+        |> Enum.map(&String.replace(&1, ~r/@(type|opaque) /, ""))
+
+      assert unsorted == Enum.sort(unsorted)
+    end
+
     test "prints type documentation" do
       content = """
       defmodule TypeSample do