Fixes #74 (Date and DateTime accepting any map)

- Implements fix
- Adds regression test
- Updates changelog/version

README.md

@@ -204,6 +204,9 @@ Details:
 - [ ] Per-module or even per-spec settings to turn on/off, configure formatter, etc.
 
 ### Changelog
+- 0.10.2 - 
+  - Fixes:
+    - Fixes issue where FixedMaps would accept maps any maps (even those missing the required keys) sometimes. (c.f. #74)
 - 0.10.1 - 
   - Fixes:
     - Swaps `Murmur` out for Erlang's builtin `:erlang.phash2/2` to generate data for function-types, allowing the removal of the optional dependency on the `:murmur` library.

lib/type_check/builtin/fixed_map.ex

@@ -27,8 +27,8 @@ defmodule TypeCheck.Builtin.FixedMap do
 
     def to_check(s, param) do
       res = quote generated: true, location: :keep do
-        with :ok <- unquote(map_check(param, s)),
-             :ok <- unquote(build_keys_presence_ast(s, param)),
+        with {:ok, _, _} <- unquote(map_check(param, s)),
+             {:ok, _, _} <- unquote(build_keys_presence_ast(s, param)),
              {:ok, bindings3, altered_param} <- unquote(build_keypairs_checks_ast(s.keypairs, param, s)) do
           {:ok, bindings3, altered_param}
         end
@@ -61,7 +61,7 @@ defmodule TypeCheck.Builtin.FixedMap do
 
         case unquote(required_keys) -- actual_keys do
           [] ->
-            :ok
+            {:ok, [], unquote(param)}
 
           missing_keys ->
             {:error,

mix.exs

@@ -6,7 +6,7 @@ defmodule TypeCheck.MixProject do
   def project do
     [
       app: :type_check,
-      version: "0.10.1",
+      version: "0.10.2",
       elixir: "~> 1.9",
       start_permanent: Mix.env() == :prod,
       deps: deps(),

test/type_check/builtin/fixed_map_test.exs

@@ -0,0 +1,25 @@
+defmodule TypeCheck.Builtin.FixedMapTest do
+  use ExUnit.Case, async: true
+  use TypeCheck
+
+  defmodule UnrelatedStruct do
+    defstruct []
+  end
+
+  # Regression test for issue #74
+  test "Date.t() only accepts valid dates" do
+    fun = &TypeCheck.conforms(&1, Date.t())
+
+
+    assert {:ok, _} = fun.(Date.utc_today())
+
+    assert {:error, _} = fun.(DateTime.utc_now())
+    assert {:error, _} = fun.(%{})
+    assert {:error, _} = fun.(%UnrelatedStruct{})
+
+    assert {:error, _} = fun.([])
+    assert {:error, _} = fun.(6)
+    assert {:error, _} = fun.("some string")
+  end
+
+end