Start using it

lib/elixir/test/elixir/enum_test.exs

@@ -1956,20 +1956,15 @@ defmodule EnumTest.SideEffects do
   end
 
   test "take/2 does not consume next without a need" do
-    path = tmp_path("oneliner.txt")
-    File.mkdir(Path.dirname(path))
+    path = Path.join([tmp_dir!(), "oneliner.txt"])
 
-    try do
-      File.write!(path, "ONE")
+    File.write!(path, "ONE")
 
-      File.open!(path, [], fn file ->
-        iterator = IO.stream(file, :line)
-        assert Enum.take(iterator, 1) == ["ONE"]
-        assert Enum.take(iterator, 5) == []
-      end)
-    after
-      File.rm(path)
-    end
+    File.open!(path, [], fn file ->
+      iterator = IO.stream(file, :line)
+      assert Enum.take(iterator, 1) == ["ONE"]
+      assert Enum.take(iterator, 5) == []
+    end)
   end
 
   test "take/2 with no elements works as no-op" do

lib/ex_unit/test/ex_unit/failures_manifest_test.exs

@@ -4,7 +4,7 @@ defmodule ExUnit.FailuresManifestTest do
   use ExUnit.Case, async: false
 
   import ExUnit.FailuresManifest
-  import ExUnit.TestHelpers, only: [tmp_path: 0, in_tmp: 2]
+  import ExUnit.TestHelpers, only: [in_tmp: 2]
 
   @passed nil
   @skipped {:skipped, "reason"}
@@ -96,14 +96,16 @@ defmodule ExUnit.FailuresManifestTest do
 
   @manifest_path "example.manifest"
 
+  defp manifest_path() do
+    Path.join([tmp_dir!(), "example.manifest"])
+  end
+
   describe "write!/2" do
     test "stores a manifest that can later be read with read/1", context do
       manifest = non_blank_manifest(context)
 
-      in_tmp(context.test, fn ->
-        assert write!(manifest, @manifest_path) == :ok
-        assert read(@manifest_path) == manifest
-      end)
+      assert write!(manifest, manifest_path()) == :ok
+      assert read(manifest_path()) == manifest
     end
 
     test "prunes tests from files that no longer exist", context do
@@ -143,9 +145,7 @@ defmodule ExUnit.FailuresManifestTest do
 
   describe "read/1" do
     test "returns a blank manifest when loading a file that does not exit" do
-      path = tmp_path() <> "missing.manifest"
-      refute File.exists?(path)
-      assert read(path) == new()
+      assert read(tmp_dir!() <> "missing.manifest") == new()
     end
 
     test "returns a blank manifest when the file is corrupted", context do

lib/mix/test/mix/shell_test.exs

@@ -20,8 +20,7 @@ defmodule Mix.ShellTest do
 
   test "with :cd" do
     Mix.shell(Mix.Shell.IO)
-    tmp_dir = System.tmp_dir()
-    File.mkdir_p!(tmp_dir)
+    tmp_dir = tmp_dir!()
     {pwd, 0} = System.cmd("pwd", [], cd: tmp_dir)
 
     assert ExUnit.CaptureIO.capture_io(fn ->