Add tests

tests/test_cli_compile.py

@@ -3102,3 +3102,33 @@ def test_invalid_cli_boolean_flag_config_option_captured(
 
     assert out.exit_code == 2
     assert "No such config key 'no_annnotate'." in out.stderr
+
+
+strip_extras_warning = (
+    "WARNING: --strip-extras is becoming the default in version 8.0.0."
+)
+
+
+def test_show_warning_on_default_strip_extras_option(
+    runner, make_package, make_sdist, tmp_path
+):
+    req_in = tmp_path / "requirements.in"
+    req_in.touch()
+
+    out = runner.invoke(cli, req_in.as_posix())
+
+    assert out.exit_code == 0
+    assert strip_extras_warning in out.stderr
+
+
+@pytest.mark.parametrize("option", ("--strip-extras", "--no-strip-extras"))
+def test_do_not_show_warning_on_explicit_strip_extras_option(
+    runner, make_package, make_sdist, tmp_path, option
+):
+    req_in = tmp_path / "requirements.in"
+    req_in.touch()
+
+    out = runner.invoke(cli, [option, req_in.as_posix()])
+
+    assert out.exit_code == 0
+    assert strip_extras_warning not in out.stderr