Add --no-strip-extras and warn about strip extras by default

README.md

@@ -564,9 +564,12 @@ This section lists `pip-tools` features that are currently deprecated.
 - In the next major release, the `--allow-unsafe` behavior will be enabled by
   default (https://github.com/jazzband/pip-tools/issues/989).
   Use `--no-allow-unsafe` to keep the old behavior. It is recommended
-  to pass the `--allow-unsafe` now to adapt to the upcoming change.
+  to pass `--allow-unsafe` now to adapt to the upcoming change.
 - The legacy resolver is deprecated and will be removed in future versions.
   The new default is `--resolver=backtracking`.
+- In the next major release, the `--strip-extras` behavior will be enabled by
+  default (https://github.com/jazzband/pip-tools/issues/1613).
+  Use `--no-strip-extras` to keep the old behavior.
 
 ### A Note on Resolvers
 

piptools/scripts/compile.py

@@ -226,9 +226,9 @@ def _determine_linesep(
     ),
 )
 @click.option(
-    "--strip-extras",
+    "--strip-extras/--no-strip-extras",
     is_flag=True,
-    default=False,
+    default=None,
     help="Assure output file is constraints compatible, avoiding use of extras.",
 )
 @click.option(
@@ -367,7 +367,7 @@ def cli(
     output_file: LazyFile | IO[Any] | None,
     newline: str,
     allow_unsafe: bool,
-    strip_extras: bool,
+    strip_extras: bool | None,
     generate_hashes: bool,
     reuse_hashes: bool,
     src_files: tuple[str, ...],
@@ -678,6 +678,15 @@ def cli(
         strategy=newline, filenames=(output_file.name, *src_files)
     )
 
+    if strip_extras is None:
+        strip_extras = False
+        log.warning(
+            "WARNING: --strip-extras is becoming the default "
+            "in version 8.0.0. To silence this warning, "
+            "either use --strip-extras to opt into the new default "
+            "or use --no-strip-extras to retain the existing behavior."
+        )
+
     ##
     # Output
     ##

tests/test_cli_compile.py

@@ -2950,20 +2950,22 @@ def test_compile_recursive_extras(runner, tmp_path, current_resolver):
         [
             "--no-header",
             "--no-annotate",
-            "--no-emit-find-links",
+            "--no-emit-options",
             "--extra",
             "dev",
             "--find-links",
             os.fspath(MINIMAL_WHEELS_PATH),
             os.fspath(tmp_path / "pyproject.toml"),
+            "--output-file",
+            "-",
         ],
     )
     expected = rf"""foo[footest] @ {tmp_path.as_uri()}
 small-fake-a==0.2
 small-fake-b==0.3
 """
     assert out.exit_code == 0
-    assert expected == out.stderr
+    assert expected == out.stdout
 
 
 def test_config_option(pip_conf, runner, tmp_path, make_config_file):
@@ -3115,3 +3117,33 @@ 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