Add tests for warning

Author: Yuki Ito

lib/elixir/test/elixir/kernel/warning_test.exs

@@ -5,18 +5,164 @@ defmodule Kernel.WarningTest do
 
   import ExUnit.CaptureIO
 
-  test :invalid_token do
+  test :unused_variable do
     assert capture_io(fn ->
+      Code.eval_string """
       defmodule Sample do
+        def hello(arg), do: nil
+      end
+      """
+    end) =~ %r"variable arg is unused"
+  after
+    purge Sample
+  end
+
+  test :unused_function do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample1 do
+        defp hello, do: nil
+      end
+      """
+    end) =~ %r"function hello/0 is unused"
+
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample2 do
         defp hello(0), do: hello(1)
         defp hello(1), do: :ok
       end
+      """
     end) =~ %r"function hello/1 is unused"
+
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample3 do
+        def a, do: nil
+        def b, do: d(10)
+        defp c(x, y // 1), do: [x, y]
+        defp d(x), do: x
+      end
+      """
+    end) =~ %r"function c/2 is unused"
+
+  after
+    purge [Sample1, Sample2, Sample3]
+  end
+
+  test :unused_macro do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample do
+        defmacrop hello, do: nil
+      end
+      """
+    end) =~ %r"macro hello/0 is unused"
   after
     purge Sample
   end
 
-  defp purge(module) do
+  test :unsued_default_args do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample1 do
+        def a, do: b(1,2,3)
+        defp b(arg1 // 1, arg2 // 2, arg3 // 3), do: [arg1, arg2, arg3]
+      end
+      """
+    end) =~ %r"default arguments in b/3 are never used"
+
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample2 do
+        def a, do: b(1,2)
+        defp b(arg1 // 1, arg2 // 2, arg3 // 3), do: [arg1, arg2, arg3]
+      end
+      """
+    end) =~ %r"the first 2 default arguments in b/3 are never used"
+
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample3 do
+        def a, do: b(1)
+        defp b(arg1 // 1, arg2 // 2, arg3 // 3), do: [arg1, arg2, arg3]
+      end
+      """
+    end) =~ %r"the first default argument in b/3 is never used"
+
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample4 do
+        def a, do: b(1)
+        defp b(arg1 // 1, arg2, arg3 // 3), do: [arg1, arg2, arg3]
+      end
+      """
+    end) == nil
+  after
+    purge [Sample1, Sample2, Sample3, Sample4]
+  end
+
+  test :unused_import do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample1 do
+        def hello, do: nil
+      end
+
+      defmodule Sample2 do
+        import Sample1
+        def a, do: nil
+      end
+      """
+    end) =~ %r"unused import Sample1"
+  after
+    purge [Sample1, Sample2]
+  end
+
+  test :clause_not_match do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample do
+        def hello, do: nil
+        def hello, do: nil
+      end
+      """
+    end) =~ %r"this clause cannot match because a previous clause at line 2 always matches"
+  after
+    purge Sample
+  end
+
+  test :clause_with_defaults_should_be_first do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample do
+        def hello(arg), do: nil
+        def hello(arg // 0), do: nil
+      end
+      """
+    end) =~ %r"clause with defaults should be the first clause in function hello/1"
+  after
+    purge Sample
+  end
+
+  test :multiple_clauses_with_defaults do
+    assert capture_io(fn ->
+      Code.eval_string """
+      defmodule Sample do
+        def hello(arg // 0), do: nil
+        def hello(arg // 1), do: nil
+      end
+      """
+    end) =~ %r"function hello/1 has default values and multiple clauses, use a separate clause for declaring defaults"
+  after
+    purge Sample
+  end
+
+  defp purge(list) when is_list(list) do
+    Enum.each list, purge(&1)
+  end
+
+  defp purge(module) when is_atom(module) do
     :code.delete module
     :code.purge module
   end