diff --git a/.check.exs b/.check.exs
index 9c2738e..19b50a2 100644
--- a/.check.exs
+++ b/.check.exs
@@ -13,6 +13,7 @@ ex_doc_config =
     {:ex_doc, ex_doc_config},
     {:formatter, env: %{"MIX_ENV" => "test"}},
     {:mix_audit, env: %{"MIX_ENV" => "test"}},
-    {:sobelow, "mix sobelow --exit --skip"}
+    {:sobelow, "mix sobelow --exit --skip"},
+    {:gettext, false}
   ]
 ]
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index fe49352..3554a50 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -12,8 +12,10 @@ jobs:
         include:
           - elixir: '1.16.1'
             otp: '26.2.2'
-          - elixir: '1.14.2'
-            otp: '25.1.2'
+          - elixir: '1.14.5'
+            otp: '24.3.4.16'
+          - elixir: '1.12.3'
+            otp: '22.3.4.26'
 
     runs-on: ubuntu-20.04
 
diff --git a/lib/ex_check/check/compiler.ex b/lib/ex_check/check/compiler.ex
index e806228..14ebedb 100644
--- a/lib/ex_check/check/compiler.ex
+++ b/lib/ex_check/check/compiler.ex
@@ -58,7 +58,9 @@ defmodule ExCheck.Check.Compiler do
             else: actual_apps_paths
 
         tool_instances =
-          Enum.map(apps_paths, fn {app_name, app_dir} ->
+          apps_paths
+          |> Enum.sort_by(&elem(&1, 0))
+          |> Enum.map(fn {app_name, app_dir} ->
             final_tool_opts = Keyword.update(tool_opts, :cd, app_dir, &Path.join(app_dir, &1))
             {{tool_name, app_name}, final_tool_opts}
           end)
diff --git a/lib/ex_check/manifest.ex b/lib/ex_check/manifest.ex
index 9b2728a..c68917b 100644
--- a/lib/ex_check/manifest.ex
+++ b/lib/ex_check/manifest.ex
@@ -61,7 +61,7 @@ defmodule ExCheck.Manifest do
   defp serialize_tool_name({tool, app}), do: "#{app}/#{tool}"
   defp serialize_tool_name(tool), do: tool
 
-  @escape Enum.map(' [~#%&*{}\\:<>?/+|"]', &<<&1::utf8>>)
+  @escape Enum.map(~c" [~#%&*{}\\:<>?/+|\"]", &<<&1::utf8>>)
 
   defp get_path(opts) do
     Keyword.get_lazy(opts, :manifest, fn ->
diff --git a/mix.exs b/mix.exs
index a0f44f3..5bf8f67 100644
--- a/mix.exs
+++ b/mix.exs
@@ -8,7 +8,7 @@ defmodule ExCheck.MixProject do
     [
       app: :ex_check,
       version: @version,
-      elixir: "~> 1.14",
+      elixir: "~> 1.12",
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,
       deps: deps(),
diff --git a/test/ex_check/project_cases/application_mod_test.exs b/test/ex_check/project_cases/application_mod_test.exs
index ff12334..88edaa5 100644
--- a/test/ex_check/project_cases/application_mod_test.exs
+++ b/test/ex_check/project_cases/application_mod_test.exs
@@ -46,7 +46,7 @@ defmodule ExCheck.ProjectCases.ApplicationModTest do
     application_test_path = Path.join([project_dir, "test", "application_test.exs"])
     File.write!(application_test_path, @application_test)
 
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
diff --git a/test/ex_check/project_cases/base_test.exs b/test/ex_check/project_cases/base_test.exs
index d6d176e..6b02611 100644
--- a/test/ex_check/project_cases/base_test.exs
+++ b/test/ex_check/project_cases/base_test.exs
@@ -2,7 +2,7 @@ defmodule ExCheck.ProjectCases.BaseTest do
   use ExCheck.ProjectCase, async: true
 
   test "base", %{project_dir: project_dir} do
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
@@ -12,13 +12,7 @@ defmodule ExCheck.ProjectCases.BaseTest do
     assert output =~ "dialyzer skipped due to missing package dialyxir"
     assert output =~ "ex_doc skipped due to missing package ex_doc"
     refute output =~ "npm_test"
-
-    if Version.match?(System.version(), ">= 1.10.0") do
-      assert output =~ "unused_deps success"
-    else
-      assert output =~ "unused_deps skipped due to Elixir version ="
-    end
-
+    assert output =~ "unused_deps success"
     assert output =~ "Randomized with seed"
   end
 end
diff --git a/test/ex_check/project_cases/compiler_test.exs b/test/ex_check/project_cases/compiler_test.exs
index fc5f18b..ee95efd 100644
--- a/test/ex_check/project_cases/compiler_test.exs
+++ b/test/ex_check/project_cases/compiler_test.exs
@@ -17,12 +17,13 @@ defmodule ExCheck.ProjectCases.CompilerTest do
     end
     """)
 
-    assert {output, 1} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "compiler error code 1"
     assert output =~ "variable \"a\" is unused"
 
-    assert {output, 0} = System.cmd("mix", ~w[check --except compiler --no-retry], cd: project_dir)
+    output =
+      System.cmd("mix", ~w[check --except compiler --no-retry], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
diff --git a/test/ex_check/project_cases/config_and_scripts_test.exs b/test/ex_check/project_cases/config_and_scripts_test.exs
index 786bde7..8afdf76 100644
--- a/test/ex_check/project_cases/config_and_scripts_test.exs
+++ b/test/ex_check/project_cases/config_and_scripts_test.exs
@@ -54,41 +54,29 @@ defmodule ExCheck.ProjectCases.ConfigAndScriptsTest do
     File.write!(shell_script_path, @shell_script)
     File.chmod!(shell_script_path, 0o755)
 
-    supports_erl_config = Version.match?(System.version(), ">= 1.9.0")
-
-    assert {output, 0} =
-             System.cmd(
-               "elixir",
-               ["-e", "Application.put_env(:elixir, :ansi_enabled, true)", "-S", "mix", "check"],
-               cd: project_dir,
-               stderr_to_stdout: true
-             )
+    output =
+      System.cmd(
+        "elixir",
+        ["-e", "Application.put_env(:elixir, :ansi_enabled, true)", "-S", "mix", "check"],
+        cd: project_dir,
+        stderr_to_stdout: true
+      )
+      |> cmd_exit(0)
 
     plain_output = String.replace(output, @ansi_code_regex, "")
 
     assert plain_output =~ "compiler success"
     refute plain_output =~ "formatter success"
     assert plain_output =~ "ex_unit success"
-
-    if Version.match?(System.version(), ">= 1.10.0") do
-      assert plain_output =~ "unused_deps fix success"
-    end
-
+    assert plain_output =~ "unused_deps fix success"
     refute plain_output =~ "credo skipped due to missing package credo"
     refute plain_output =~ "gettext skipped due to missing package credo"
     assert plain_output =~ "my_mix_task success"
     assert plain_output =~ "my_elixir_script success"
     assert plain_output =~ "my_shell_script success"
-
     assert output =~ "sometag"
     assert output =~ IO.ANSI.yellow() <> IO.ANSI.faint() <> "my mix task a prod"
-
-    if supports_erl_config do
-      assert output =~ IO.ANSI.blue() <> IO.ANSI.faint() <> "my elixir script a"
-    else
-      assert output =~ "my elixir script a"
-    end
-
+    assert output =~ IO.ANSI.blue() <> IO.ANSI.faint() <> "my elixir script a"
     assert output =~ "my shell script a b xyz"
     assert plain_output =~ ~r/running my_shell_script.*running my_mix_task.*running ex_unit/s
   end
diff --git a/test/ex_check/project_cases/deps_test.exs b/test/ex_check/project_cases/deps_test.exs
index 991cbae..95d455f 100644
--- a/test/ex_check/project_cases/deps_test.exs
+++ b/test/ex_check/project_cases/deps_test.exs
@@ -42,7 +42,7 @@ defmodule ExCheck.ProjectCases.DepsTest do
     config_path = Path.join(project_dir, ".check.exs")
     File.write!(config_path, @config)
 
-    assert {output, 1} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "a success"
     assert output =~ "b success"
@@ -63,7 +63,7 @@ defmodule ExCheck.ProjectCases.DepsTest do
     config_path = Path.join(project_dir, ".check.exs")
     File.write!(config_path, @config)
 
-    assert {output, 1} = System.cmd("mix", ~w[check --no-parallel], cd: project_dir)
+    output = System.cmd("mix", ~w[check --no-parallel], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "a success"
     assert output =~ "b success"
diff --git a/test/ex_check/project_cases/detect_test.exs b/test/ex_check/project_cases/detect_test.exs
index b588321..5f3e668 100644
--- a/test/ex_check/project_cases/detect_test.exs
+++ b/test/ex_check/project_cases/detect_test.exs
@@ -15,7 +15,7 @@ defmodule ExCheck.ProjectCases.DetectTest do
     config_path = Path.join(project_dir, ".check.exs")
     File.write!(config_path, @config)
 
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "credo skipped due to missing package credo"
     assert output =~ "bad_dir skipped due to missing directory bad_directory"
diff --git a/test/ex_check/project_cases/external_tools_test.exs b/test/ex_check/project_cases/external_tools_test.exs
index f934b8c..e3e54bb 100644
--- a/test/ex_check/project_cases/external_tools_test.exs
+++ b/test/ex_check/project_cases/external_tools_test.exs
@@ -2,35 +2,19 @@ defmodule ExCheck.ProjectCases.ExternalToolsTest do
   use ExCheck.ProjectCase, async: true
 
   test "external tools (except dialyzer)", %{project_dir: project_dir} do
-    tools =
-      if Version.match?(System.version(), "< 1.10.0") do
-        [:ex_check, :credo, :doctor, :sobelow, :mix_audit]
-      else
-        [:ex_check, :credo, :doctor, :ex_doc, :gettext, :sobelow, :mix_audit]
-      end
-
+    tools = [:ex_check, :credo, :doctor, :ex_doc, :gettext, :sobelow, :mix_audit]
     set_mix_deps(project_dir, tools)
 
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_dir, env: %{"MIX_ENV" => "dev"})
+    output =
+      System.cmd("mix", ~w[check], cd: project_dir, env: %{"MIX_ENV" => "dev"}) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
     assert output =~ "ex_unit success"
     assert output =~ "credo success"
     assert output =~ "gettext success"
-
-    if Version.match?(System.version(), ">= 1.8.0") do
-      assert output =~ "doctor success"
-    else
-      assert output =~ "doctor skipped"
-    end
-
-    if Version.match?(System.version(), ">= 1.10.0") do
-      assert output =~ "ex_doc success"
-    else
-      assert output =~ "ex_doc skipped due to missing package ex_doc"
-    end
-
+    assert output =~ "doctor success"
+    assert output =~ "ex_doc success"
     assert output =~ "sobelow success"
     assert output =~ "dialyzer skipped due to missing package dialyxir"
     assert output =~ "mix_audit success"
diff --git a/test/ex_check/project_cases/formatter_issue_test.exs b/test/ex_check/project_cases/formatter_issue_test.exs
index 4743b9e..d741fbf 100644
--- a/test/ex_check/project_cases/formatter_issue_test.exs
+++ b/test/ex_check/project_cases/formatter_issue_test.exs
@@ -9,7 +9,7 @@ defmodule ExCheck.ProjectCases.FormatterIssueTest do
 
     File.write!(invalid_file_path, "IO.inspect( 1 )")
 
-    assert {output, 1} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "compiler success"
     assert output =~ "formatter error code 1"
diff --git a/test/ex_check/project_cases/gen_config_test.exs b/test/ex_check/project_cases/gen_config_test.exs
index 3d0d1b0..2e4f63d 100644
--- a/test/ex_check/project_cases/gen_config_test.exs
+++ b/test/ex_check/project_cases/gen_config_test.exs
@@ -4,15 +4,15 @@ defmodule ExCheck.ProjectCases.GenConfigTest do
   test "gen config", %{project_dir: project_dir} do
     File.rm!(Path.join(project_dir, ".check.exs"))
 
-    assert {output, 0} = System.cmd("mix", ~w[check.gen.config], cd: project_dir)
+    output = System.cmd("mix", ~w[check.gen.config], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "creating .check.exs"
 
-    assert {output, 0} = System.cmd("mix", ~w[check.gen.config], cd: project_dir)
+    output = System.cmd("mix", ~w[check.gen.config], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ ".check.exs already exists, skipped"
 
-    assert {output, 0} = System.cmd("mix", ~w[check --no-fix], cd: project_dir)
+    output = System.cmd("mix", ~w[check --no-fix], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
diff --git a/test/ex_check/project_cases/manifest_test.exs b/test/ex_check/project_cases/manifest_test.exs
index 473ad18..47e9754 100644
--- a/test/ex_check/project_cases/manifest_test.exs
+++ b/test/ex_check/project_cases/manifest_test.exs
@@ -9,7 +9,7 @@ defmodule ExCheck.ProjectCases.ManifestTest do
 
     File.write!(invalid_file_path, "IO.inspect( 1 )")
 
-    assert {output, 1} = System.cmd("mix", ~w[check --manifest manifest.txt], cd: project_dir)
+    output = System.cmd("mix", ~w[check --manifest manifest.txt], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "compiler success"
     assert output =~ "formatter error code 1"
@@ -38,16 +38,9 @@ defmodule ExCheck.ProjectCases.ManifestTest do
       |> String.split("\n")
       |> Enum.sort()
 
-    expected_manifest =
-      if Version.match?(System.version(), ">= 1.10.0") do
-        expected_manifest
-      else
-        (expected_manifest -- ["PASS unused_deps"]) ++ ["SKIP unused_deps"]
-      end
-
     assert manifest |> String.split("\n") |> Enum.sort() == expected_manifest
 
-    assert {output, 1} = System.cmd("mix", ~w[check --manifest manifest.txt], cd: project_dir)
+    output = System.cmd("mix", ~w[check --manifest manifest.txt], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "retrying automatically"
     assert output =~ "compiler success"
@@ -59,8 +52,8 @@ defmodule ExCheck.ProjectCases.ManifestTest do
     refute output =~ "ex_doc skipped due to missing package ex_doc"
     refute output =~ "mix_audit skipped due to missing package mix_audit"
 
-    assert {output, 1} =
-             System.cmd("mix", ~w[check --manifest manifest.txt --retry], cd: project_dir)
+    output =
+      System.cmd("mix", ~w[check --manifest manifest.txt --retry], cd: project_dir) |> cmd_exit(1)
 
     refute output =~ "retrying automatically"
     assert output =~ "compiler success"
@@ -72,8 +65,9 @@ defmodule ExCheck.ProjectCases.ManifestTest do
     refute output =~ "ex_doc skipped due to missing package ex_doc"
     refute output =~ "mix_audit skipped due to missing package mix_audit"
 
-    assert {output, 1} =
-             System.cmd("mix", ~w[check --manifest manifest.txt --no-retry], cd: project_dir)
+    output =
+      System.cmd("mix", ~w[check --manifest manifest.txt --no-retry], cd: project_dir)
+      |> cmd_exit(1)
 
     refute output =~ "retrying automatically"
     assert output =~ "compiler success"
@@ -85,8 +79,9 @@ defmodule ExCheck.ProjectCases.ManifestTest do
     assert output =~ "ex_doc skipped due to missing package ex_doc"
     assert output =~ "mix_audit skipped due to missing package mix_audit"
 
-    assert {output, 0} =
-             System.cmd("mix", ~w[check --manifest manifest.txt --retry --fix], cd: project_dir)
+    output =
+      System.cmd("mix", ~w[check --manifest manifest.txt --retry --fix], cd: project_dir)
+      |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter fix success"
@@ -97,8 +92,8 @@ defmodule ExCheck.ProjectCases.ManifestTest do
     refute output =~ "ex_doc skipped due to missing package ex_doc"
     refute output =~ "mix_audit skipped due to missing package mix_audit"
 
-    assert {output, 0} =
-             System.cmd("mix", ~w[check --manifest manifest.txt --retry], cd: project_dir)
+    output =
+      System.cmd("mix", ~w[check --manifest manifest.txt --retry], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     refute output =~ "formatter success"
@@ -124,14 +119,14 @@ defmodule ExCheck.ProjectCases.ManifestTest do
     end
     """)
 
-    assert {output, 1} =
-             System.cmd("mix", ~w[check --only ex_unit --only formatter], cd: project_dir)
+    output =
+      System.cmd("mix", ~w[check --only ex_unit --only formatter], cd: project_dir) |> cmd_exit(1)
 
     assert output =~ "formatter success"
     assert output =~ "ex_unit error code"
     assert output =~ "2 tests, 1 failure"
 
-    assert {output, 1} = System.cmd("mix", ~w[check --retry], cd: project_dir)
+    output = System.cmd("mix", ~w[check --retry], cd: project_dir) |> cmd_exit(1)
 
     refute output =~ "formatter"
     assert output =~ "ex_unit error code"
@@ -142,7 +137,7 @@ defmodule ExCheck.ProjectCases.ManifestTest do
       File.read!(failing_test_path) |> String.replace(":universe", ":world")
     )
 
-    assert {output, 0} = System.cmd("mix", ~w[check --retry], cd: project_dir)
+    output = System.cmd("mix", ~w[check --retry], cd: project_dir) |> cmd_exit(0)
 
     refute output =~ "formatter"
     assert output =~ "ex_unit retry success"
diff --git a/test/ex_check/project_cases/missing_test_helper_test.exs b/test/ex_check/project_cases/missing_test_helper_test.exs
index 9d10b26..dbcd8f5 100644
--- a/test/ex_check/project_cases/missing_test_helper_test.exs
+++ b/test/ex_check/project_cases/missing_test_helper_test.exs
@@ -5,7 +5,7 @@ defmodule ExCheck.ProjectCases.MissingTestHelperTest do
     test_dir_path = Path.join(project_dir, "test")
     File.rm_rf!(test_dir_path)
 
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_dir)
+    output = System.cmd("mix", ~w[check], cd: project_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
diff --git a/test/ex_check/umbrella_project_cases/asset_testing_test.exs b/test/ex_check/umbrella_project_cases/asset_testing_test.exs
index 160ae20..5caa7fe 100644
--- a/test/ex_check/umbrella_project_cases/asset_testing_test.exs
+++ b/test/ex_check/umbrella_project_cases/asset_testing_test.exs
@@ -14,8 +14,8 @@ defmodule ExCheck.UmbrellaProjectCases.AssetTestingTest do
     File.mkdir_p!(Path.dirname(package_json_path))
     File.write!(package_json_path, @package_json)
 
-    assert {_, 0} = System.cmd("mix", ~w[compile], cd: project_root_dir)
-    assert {output, 1} = System.cmd("mix", ~w[check], cd: project_root_dir)
+    System.cmd("mix", ~w[compile], cd: project_root_dir) |> cmd_exit(0)
+    output = System.cmd("mix", ~w[check], cd: project_root_dir) |> cmd_exit(1)
 
     assert output =~ "npm_test in child_a error code 1"
     refute output =~ "npm_test in child_b"
diff --git a/test/ex_check/umbrella_project_cases/base_test.exs b/test/ex_check/umbrella_project_cases/base_test.exs
index b318e1b..d5396d9 100644
--- a/test/ex_check/umbrella_project_cases/base_test.exs
+++ b/test/ex_check/umbrella_project_cases/base_test.exs
@@ -2,8 +2,8 @@ defmodule ExCheck.UmbrellaProjectCases.BaseTest do
   use ExCheck.UmbrellaProjectCase, async: true
 
   test "base", %{project_dirs: [project_root_dir | _]} do
-    assert {_, 0} = System.cmd("mix", ~w[compile], cd: project_root_dir)
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_root_dir)
+    System.cmd("mix", ~w[compile], cd: project_root_dir) |> cmd_exit(0)
+    output = System.cmd("mix", ~w[check], cd: project_root_dir) |> cmd_exit(0)
 
     assert output =~ "compiler success"
     assert output =~ "formatter success"
diff --git a/test/ex_check/umbrella_project_cases/non_recursive_test.exs b/test/ex_check/umbrella_project_cases/non_recursive_test.exs
index 0150b87..c0c0ed0 100644
--- a/test/ex_check/umbrella_project_cases/non_recursive_test.exs
+++ b/test/ex_check/umbrella_project_cases/non_recursive_test.exs
@@ -13,8 +13,8 @@ defmodule ExCheck.UmbrellaProjectCases.NonRecursiveTest do
     config_path = Path.join(project_root_dir, ".check.exs")
     File.write!(config_path, @config)
 
-    assert {_, 0} = System.cmd("mix", ~w[compile], cd: project_root_dir)
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_root_dir)
+    System.cmd("mix", ~w[compile], cd: project_root_dir) |> cmd_exit(0)
+    output = System.cmd("mix", ~w[check], cd: project_root_dir) |> cmd_exit(0)
 
     assert output =~ "ex_unit success"
     refute output =~ "ex_unit in child_a success"
diff --git a/test/ex_check/umbrella_project_cases/only_specific_apps_test.exs b/test/ex_check/umbrella_project_cases/only_specific_apps_test.exs
index bc8867c..04d6048 100644
--- a/test/ex_check/umbrella_project_cases/only_specific_apps_test.exs
+++ b/test/ex_check/umbrella_project_cases/only_specific_apps_test.exs
@@ -13,18 +13,18 @@ defmodule ExCheck.UmbrellaProjectCases.OnlySpecificAppsTest do
     config_path = Path.join(project_root_dir, ".check.exs")
     File.write!(config_path, @config)
 
-    assert {_, 0} = System.cmd("mix", ~w[compile], cd: project_root_dir)
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_root_dir)
+    System.cmd("mix", ~w[compile], cd: project_root_dir) |> cmd_exit(0)
+    output = System.cmd("mix", ~w[check], cd: project_root_dir) |> cmd_exit(0)
 
     refute output =~ "ex_unit success"
     assert output =~ "ex_unit in child_a success"
     refute output =~ "ex_unit in child_b success"
 
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: child_a_dir)
+    output = System.cmd("mix", ~w[check], cd: child_a_dir) |> cmd_exit(0)
 
     assert output =~ "ex_unit success"
 
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: child_b_dir)
+    output = System.cmd("mix", ~w[check], cd: child_b_dir) |> cmd_exit(0)
 
     refute output =~ "ex_unit"
   end
diff --git a/test/ex_check/umbrella_project_cases/sequential_test.exs b/test/ex_check/umbrella_project_cases/sequential_test.exs
index 797620e..4867d39 100644
--- a/test/ex_check/umbrella_project_cases/sequential_test.exs
+++ b/test/ex_check/umbrella_project_cases/sequential_test.exs
@@ -1,35 +1,42 @@
 defmodule ExCheck.UmbrellaProjectCases.SequentialTest do
   use ExCheck.UmbrellaProjectCase, async: true
 
-  @a_script """
-  Process.sleep(1_000)
-  File.write!(Path.join("..", "a_out"), "a_out")
-  """
-
-  @b_script """
-  IO.puts(File.read!(Path.join("..", "a_out")))
-  """
-
-  @config """
-  [
-    tools: [
-      {:seq, "elixir script.exs", umbrella: [parallel: false]},
+  test "sequential", %{project_dirs: [project_root_dir, child_a_dir, child_b_dir]} do
+    script_path = Path.join(project_root_dir, "a_out")
+
+    a_script = """
+    IO.inspect({:a1, DateTime.utc_now()})
+    Process.sleep(1_000)
+    File.write!("#{script_path}", "a_out")
+    IO.inspect({:a2, DateTime.utc_now()})
+    """
+
+    b_script = """
+    IO.inspect({:b1, DateTime.utc_now()})
+    Process.sleep(1_000)
+    IO.puts(File.read!("#{script_path}"))
+    IO.inspect({:b2, DateTime.utc_now()})
+    """
+
+    config = """
+    [
+      tools: [
+        {:seq, "elixir script.exs", umbrella: [parallel: false]},
+      ]
     ]
-  ]
-  """
+    """
 
-  test "sequential", %{project_dirs: [project_root_dir, child_a_dir, child_b_dir]} do
     config_path = Path.join(project_root_dir, ".check.exs")
-    File.write!(config_path, @config)
+    File.write!(config_path, config)
 
     child_a_script_path = Path.join(child_a_dir, "script.exs")
-    File.write!(child_a_script_path, @a_script)
+    File.write!(child_a_script_path, a_script)
 
     child_b_script_path = Path.join(child_b_dir, "script.exs")
-    File.write!(child_b_script_path, @b_script)
+    File.write!(child_b_script_path, b_script)
 
-    assert {_, 0} = System.cmd("mix", ~w[compile], cd: project_root_dir)
-    assert {output, 0} = System.cmd("mix", ~w[check], cd: project_root_dir)
+    System.cmd("mix", ~w[compile], cd: project_root_dir) |> cmd_exit(0)
+    output = System.cmd("mix", ~w[check], cd: project_root_dir) |> cmd_exit(0)
 
     assert output =~ "seq in child_a success"
     assert output =~ "seq in child_b success"
diff --git a/test/support/ex_check/case_helpers.ex b/test/support/ex_check/case_helpers.ex
new file mode 100644
index 0000000..652d90f
--- /dev/null
+++ b/test/support/ex_check/case_helpers.ex
@@ -0,0 +1,101 @@
+defmodule ExCheck.CaseHelpers do
+  @moduledoc false
+
+  use ExUnit.CaseTemplate
+
+  @default_config """
+  [
+    fix: false
+  ]
+  """
+
+  def cmd_exit({output, code}, expected_code) do
+    assert code == expected_code,
+           "unexpected exit code #{code} (expected #{expected_code}):\n\n#{output}"
+
+    output
+  end
+
+  def create_tmp_directory do
+    timestamp = DateTime.utc_now() |> DateTime.to_unix(:microsecond)
+    unique_id = :crypto.strong_rand_bytes(12) |> Base.url_encode64()
+
+    tmp_dir =
+      System.tmp_dir!()
+      |> Path.join("ex_check_test")
+      |> Path.join("#{timestamp}-#{unique_id}")
+
+    File.mkdir_p!(tmp_dir)
+
+    tmp_dir
+  end
+
+  def remove_tmp_directory(tmp_dir) do
+    File.rm_rf!(tmp_dir)
+  end
+
+  def set_mix_deps(project_dirs, deps) when is_list(project_dirs) do
+    Enum.map(project_dirs, &set_mix_deps(&1, deps))
+  end
+
+  def set_mix_deps(project_dir, deps) do
+    config_path = "#{project_dir}/mix.exs"
+    deps_from = ~r/ *defp deps.*end\n/Us
+
+    deps_list =
+      Enum.map(deps, fn
+        :ex_check ->
+          "{:ex_check, path: \"#{File.cwd!()}\", only: [:dev, :test], runtime: false}"
+
+        dep ->
+          "{:#{dep}, \">= 0.0.0\", only: :dev, runtime: false}"
+      end)
+
+    deps_to = """
+      defp deps do
+        [
+          #{Enum.join(deps_list, ",\n      ")}
+        ]
+      end
+    """
+
+    new_config =
+      config_path
+      |> File.read!()
+      |> String.replace(deps_from, deps_to)
+
+    unless String.contains?(new_config, "ex_check"), do: raise("unable to add ex_check dep")
+
+    File.write!(config_path, new_config)
+    {_, 0} = System.cmd("mix", ~w[format], cd: project_dir)
+    {_, 0} = System.cmd("mix", ~w[deps.get], cd: project_dir)
+  end
+
+  def set_mix_app_mod(project_dir, mod) do
+    config_path = "#{project_dir}/mix.exs"
+    app_from = ~r/ *def application.*end\n/Us
+
+    app_to = """
+      def application do
+        [
+          mod: {#{mod}, []}
+        ]
+      end
+    """
+
+    new_config =
+      config_path
+      |> File.read!()
+      |> String.replace(app_from, app_to)
+
+    unless String.contains?(new_config, mod), do: raise("unable to set #{mod} app mod")
+
+    File.write!(config_path, new_config)
+    {_, 0} = System.cmd("mix", ~w[format], cd: project_dir)
+  end
+
+  def write_default_config(project_dir) do
+    config_path = Path.join(project_dir, ".check.exs")
+    File.write!(config_path, @default_config)
+  end
+end
diff --git a/test/support/ex_check/project_case.ex b/test/support/ex_check/project_case.ex
index b46e081..2c189a3 100644
--- a/test/support/ex_check/project_case.ex
+++ b/test/support/ex_check/project_case.ex
@@ -3,14 +3,9 @@ defmodule ExCheck.ProjectCase do
 
   use ExUnit.CaseTemplate
 
-  @default_config """
-  [
-    fix: false
-  ]
-  """
-
   using do
     quote do
+      import ExCheck.CaseHelpers
       import ExCheck.ProjectCase
 
       @moduletag timeout: 5 * 60 * 1_000
@@ -28,88 +23,9 @@ defmodule ExCheck.ProjectCase do
     end
   end
 
-  def create_tmp_directory do
-    timestamp = DateTime.utc_now() |> DateTime.to_unix(:microsecond)
-    unique_id = :crypto.strong_rand_bytes(12) |> Base.url_encode64()
-
-    tmp_dir =
-      System.tmp_dir!()
-      |> Path.join("ex_check_test")
-      |> Path.join("#{timestamp}-#{unique_id}")
-
-    File.mkdir_p!(tmp_dir)
-
-    tmp_dir
-  end
-
-  def remove_tmp_directory(tmp_dir) do
-    File.rm_rf!(tmp_dir)
-  end
-
   def create_mix_project(root_dir) do
     System.cmd("mix", ~w(new test_project), cd: root_dir)
 
     Path.join(root_dir, "test_project")
   end
-
-  def set_mix_deps(project_dir, deps) do
-    config_path = "#{project_dir}/mix.exs"
-    deps_from = ~r/ *defp deps.*end\n/Us
-
-    deps_list =
-      Enum.map(deps, fn
-        :ex_check ->
-          "{:ex_check, path: \"#{File.cwd!()}\", only: [:dev, :test], runtime: false}"
-
-        dep ->
-          "{:#{dep}, \">= 0.0.0\", only: :dev, runtime: false}"
-      end)
-
-    deps_to = """
-      defp deps do
-        [
-          #{Enum.join(deps_list, ",\n      ")}
-        ]
-      end
-    """
-
-    new_config =
-      config_path
-      |> File.read!()
-      |> String.replace(deps_from, deps_to)
-
-    unless String.contains?(new_config, "ex_check"), do: raise("unable to add ex_check dep")
-
-    File.write!(config_path, new_config)
-    {_, 0} = System.cmd("mix", ~w[format], cd: project_dir)
-    {_, 0} = System.cmd("mix", ~w[deps.get], cd: project_dir)
-  end
-
-  def set_mix_app_mod(project_dir, mod) do
-    config_path = "#{project_dir}/mix.exs"
-    app_from = ~r/ *def application.*end\n/Us
-
-    app_to = """
-      def application do
-        [
-          mod: {#{mod}, []}
-        ]
-      end
-    """
-
-    new_config =
-      config_path
-      |> File.read!()
-      |> String.replace(app_from, app_to)
-
-    unless String.contains?(new_config, mod), do: raise("unable to set #{mod} app mod")
-
-    File.write!(config_path, new_config)
-    {_, 0} = System.cmd("mix", ~w[format], cd: project_dir)
-  end
-
-  def write_default_config(project_dir) do
-    config_path = Path.join(project_dir, ".check.exs")
-    File.write!(config_path, @default_config)
-  end
 end
diff --git a/test/support/ex_check/umbrella_project_case.ex b/test/support/ex_check/umbrella_project_case.ex
index 18afd03..f662ceb 100644
--- a/test/support/ex_check/umbrella_project_case.ex
+++ b/test/support/ex_check/umbrella_project_case.ex
@@ -3,14 +3,9 @@ defmodule ExCheck.UmbrellaProjectCase do
 
   use ExUnit.CaseTemplate
 
-  @default_config """
-  [
-    fix: false
-  ]
-  """
-
   using do
     quote do
+      import ExCheck.CaseHelpers
       import ExCheck.UmbrellaProjectCase
 
       @moduletag timeout: 5 * 60 * 1_000
@@ -32,24 +27,6 @@ defmodule ExCheck.UmbrellaProjectCase do
     end
   end
 
-  def create_tmp_directory do
-    timestamp = DateTime.utc_now() |> DateTime.to_unix(:microsecond)
-    unique_id = :crypto.strong_rand_bytes(12) |> Base.url_encode64()
-
-    tmp_dir =
-      System.tmp_dir!()
-      |> Path.join("ex_check_test")
-      |> Path.join("#{timestamp}-#{unique_id}")
-
-    File.mkdir_p!(tmp_dir)
-
-    tmp_dir
-  end
-
-  def remove_tmp_directory(tmp_dir) do
-    File.rm_rf!(tmp_dir)
-  end
-
   def create_mix_project(root_dir, opts \\ []) do
     name = Keyword.get(opts, :name, "test_project")
     umbrella = Keyword.get(opts, :umbrella, false)
@@ -59,69 +36,4 @@ defmodule ExCheck.UmbrellaProjectCase do
 
     Path.join(root_dir, name)
   end
-
-  def set_mix_deps(project_dirs, deps) when is_list(project_dirs) do
-    Enum.map(project_dirs, &set_mix_deps(&1, deps))
-  end
-
-  def set_mix_deps(project_dir, deps) do
-    config_path = "#{project_dir}/mix.exs"
-    deps_from = ~r/ *defp deps.*end\n/Us
-
-    deps_list =
-      Enum.map(deps, fn
-        :ex_check ->
-          "{:ex_check, path: \"#{File.cwd!()}\", only: [:dev, :test], runtime: false}"
-
-        dep ->
-          "{:#{dep}, \">= 0.0.0\", only: :dev, runtime: false}"
-      end)
-
-    deps_to = """
-      defp deps do
-        [
-          #{Enum.join(deps_list, ",\n      ")}
-        ]
-      end
-    """
-
-    new_config =
-      config_path
-      |> File.read!()
-      |> String.replace(deps_from, deps_to)
-
-    unless String.contains?(new_config, "ex_check"), do: raise("unable to add ex_check dep")
-
-    File.write!(config_path, new_config)
-    {_, 0} = System.cmd("mix", ~w[format], cd: project_dir)
-    {_, 0} = System.cmd("mix", ~w[deps.get], cd: project_dir)
-  end
-
-  def set_mix_app_mod(project_dir, mod) do
-    config_path = "#{project_dir}/mix.exs"
-    app_from = ~r/ *def application.*end\n/Us
-
-    app_to = """
-      def application do
-        [
-          mod: {#{mod}, []}
-        ]
-      end
-    """
-
-    new_config =
-      config_path
-      |> File.read!()
-      |> String.replace(app_from, app_to)
-
-    unless String.contains?(new_config, mod), do: raise("unable to set #{mod} app mod")
-
-    File.write!(config_path, new_config)
-    {_, 0} = System.cmd("mix", ~w[format], cd: project_dir)
-  end
-
-  def write_default_config(project_dir) do
-    config_path = Path.join(project_dir, ".check.exs")
-    File.write!(config_path, @default_config)
-  end
 end