From 97c70ec4ed246055b82a6fffa98f636ef4d3c915 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gon=C3=A7alo=20Tom=C3=A1s?= <ga.tomas@outlook.pt>
Date: Sun, 20 Aug 2023 09:04:26 +0100
Subject: [PATCH] Add known_types/0 function that lists all known types (#79)

---
 lib/mime.ex        | 16 ++++++++++++++++
 test/mime_test.exs | 13 +++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/lib/mime.ex b/lib/mime.ex
index dfa736f..0126725 100644
--- a/lib/mime.ex
+++ b/lib/mime.ex
@@ -164,6 +164,22 @@ defmodule MIME do
     unquote(Macro.escape(custom_types))
   end
 
+  @doc """
+  Returns a mapping of all known types to their extensions,
+  including custom types compiled into the MIME module.
+  
+  ## Examples
+  
+      known_types()
+      #=> %{"application/json" => ["json"], ...}
+
+  """
+  @doc since: "2.1.0"
+  @spec known_types() :: %{required(String.t()) => [String.t()]}
+  def known_types do
+    unquote(Macro.escape(all_types))
+  end
+
   @doc """
   Returns the extensions associated with a given MIME type.
 
diff --git a/test/mime_test.exs b/test/mime_test.exs
index d425a2e..d5cbd4c 100644
--- a/test/mime_test.exs
+++ b/test/mime_test.exs
@@ -49,6 +49,19 @@ defmodule MIMETest do
     assert from_path("image.psd") == "image/vnd.adobe.photoshop"
   end
 
+  test "known_types/0" do
+    Application.put_env(:mime, :types, %{"application/dicom" => ["dcm"]})
+    recompile!()
+
+    assert is_map(known_types())
+
+    assert Map.has_key?(known_types(), "application/json")
+    assert Map.has_key?(known_types(), "application/dicom")
+
+    assert Map.get(known_types(), "application/json") == ["json"]
+    assert Map.get(known_types(), "application/dicom") == ["dcm"]
+  end
+
   test "types map is sorted" do
     quoted = Code.string_to_quoted!(File.read!("lib/mime.ex"))