Use pep517 to load project metadata (#1311)

Co-authored-by: Albert Tugushev <albert@tugushev.ru>

piptools/scripts/compile.py

@@ -7,8 +7,12 @@
 import click
 from click.utils import safecall
 from pip._internal.commands import create_command
-from pip._internal.req.constructors import install_req_from_line
+from pip._internal.req.constructors import (
+    install_req_from_line,
+    install_req_from_req_string,
+)
 from pip._internal.utils.misc import redact_auth_from_url
+from pip._vendor.pep517 import meta
 
 from .._compat import parse_requirements
 from ..cache import DependencyCache
@@ -330,21 +334,14 @@ def cli(
     constraints = []
     for src_file in src_files:
         is_setup_file = os.path.basename(src_file) == "setup.py"
-        if is_setup_file or src_file == "-":
+        if src_file == "-":
             # pip requires filenames and not files. Since we want to support
             # piping from stdin, we need to briefly save the input from stdin
             # to a temporary file and have pip read that.  also used for
             # reading requirements from install_requires in setup.py.
             tmpfile = tempfile.NamedTemporaryFile(mode="wt", delete=False)
-            if is_setup_file:
-                from distutils.core import run_setup
-
-                dist = run_setup(src_file)
-                tmpfile.write("\n".join(dist.install_requires))
-                comes_from = f"{dist.get_name()} ({src_file})"
-            else:
-                tmpfile.write(sys.stdin.read())
-                comes_from = "-r -"
+            tmpfile.write(sys.stdin.read())
+            comes_from = "-r -"
             tmpfile.flush()
             reqs = list(
                 parse_requirements(
@@ -357,6 +354,15 @@ def cli(
             for req in reqs:
                 req.comes_from = comes_from
             constraints.extend(reqs)
+        elif is_setup_file:
+            dist = meta.load(os.path.dirname(os.path.abspath(src_file)))
+            comes_from = f"{dist.metadata.get_all('Name')[0]} ({src_file})"
+            constraints.extend(
+                [
+                    install_req_from_req_string(req, comes_from=comes_from)
+                    for req in dist.requires or []
+                ]
+            )
         else:
             constraints.extend(
                 parse_requirements(
@@ -378,7 +384,13 @@ def cli(
 
     # Filter out pip environment markers which do not match (PEP496)
     constraints = [
-        req for req in constraints if req.markers is None or req.markers.evaluate()
+        req
+        for req in constraints
+        if req.markers is None
+        # We explicitly set extra=None to filter out optional requirements
+        # since evaluating an extra marker with no environment raises UndefinedEnvironmentName
+        # (see https://packaging.pypa.io/en/latest/markers.html#usage)
+        or req.markers.evaluate({"extra": None})
     ]
 
     log.debug("Using indexes:")

tests/test_cli_compile.py

@@ -38,7 +38,17 @@ def test_command_line_overrides_pip_conf(pip_with_index_conf, runner):
     assert "Using indexes:\n  http://override.com" in out.stderr
 
 
-def test_command_line_setuptools_read(pip_conf, runner):
+@pytest.mark.network
+def test_command_line_setuptools_read(runner, make_pip_conf):
+    make_pip_conf(
+        dedent(
+            """\
+            [global]
+            disable-pip-version-check = True
+            """
+        )
+    )
+
     with open("setup.py", "w") as package:
         package.write(
             dedent(
@@ -51,16 +61,13 @@ def test_command_line_setuptools_read(pip_conf, runner):
                 """
             )
         )
-    out = runner.invoke(cli, ["--no-emit-find-links"])
+    out = runner.invoke(
+        cli,
+        ["--no-header", "--no-emit-find-links", "--find-links", MINIMAL_WHEELS_PATH],
+    )
 
     assert out.stderr == dedent(
         """\
-        #
-        # This file is autogenerated by pip-compile
-        # To update, run:
-        #
-        #    pip-compile --no-emit-find-links
-        #
         small-fake-a==0.1
             # via fake-setuptools-a (setup.py)
         """
@@ -70,6 +77,7 @@ def test_command_line_setuptools_read(pip_conf, runner):
     assert os.path.exists("requirements.txt")
 
 
+@pytest.mark.network
 @pytest.mark.parametrize(
     ("options", "expected_output_file"),
     (
@@ -85,12 +93,11 @@ def test_command_line_setuptools_read(pip_conf, runner):
         (["setup.py", "--output-file", "output.txt"], "output.txt"),
     ),
 )
-def test_command_line_setuptools_output_file(
-    pip_conf, runner, options, expected_output_file
-):
+def test_command_line_setuptools_output_file(runner, options, expected_output_file):
     """
     Test the output files for setup.py as a requirement file.
     """
+
     with open("setup.py", "w") as package:
         package.write(
             dedent(
@@ -106,7 +113,8 @@ def test_command_line_setuptools_output_file(
     assert os.path.exists(expected_output_file)
 
 
-def test_command_line_setuptools_nested_output_file(pip_conf, tmpdir, runner):
+@pytest.mark.network
+def test_command_line_setuptools_nested_output_file(tmpdir, runner):
     """
     Test the output file for setup.py in nested folder as a requirement file.
     """
@@ -127,6 +135,43 @@ def test_command_line_setuptools_nested_output_file(pip_conf, tmpdir, runner):
     assert (proj_dir / "requirements.txt").exists()
 
 
+@pytest.mark.network
+def test_setuptools_preserves_environment_markers(
+    runner, make_package, make_wheel, make_pip_conf, tmpdir
+):
+    make_pip_conf(
+        dedent(
+            """\
+            [global]
+            disable-pip-version-check = True
+            """
+        )
+    )
+
+    dists_dir = tmpdir / "dists"
+
+    foo_dir = make_package(name="foo", version="1.0")
+    make_wheel(foo_dir, dists_dir)
+
+    bar_dir = make_package(
+        name="bar", version="2.0", install_requires=['foo ; python_version >= "1"']
+    )
+    out = runner.invoke(
+        cli,
+        [
+            str(bar_dir / "setup.py"),
+            "--no-header",
+            "--no-annotate",
+            "--no-emit-find-links",
+            "--find-links",
+            str(dists_dir),
+        ],
+    )
+
+    assert out.exit_code == 0, out.stderr
+    assert out.stderr == 'foo==1.0 ; python_version >= "1"\n'
+
+
 def test_find_links_option(runner):
     with open("requirements.in", "w") as req_in:
         req_in.write("-f ./libs3")