fix(pypi): correctly aggregate the requirements files (bazel-contrib#2932)

This implements the actual fix where we are aggregating the whls and
sdists
correctly from multiple different requirements lines.

Fixes bazel-contrib#2648.
Closes bazel-contrib#2658.

Author: aignas

CHANGELOG.md

@@ -96,6 +96,8 @@ END_UNRELEASED_TEMPLATE
 * (pypi) When running under `bazel test`, be sure that temporary `requirements` file
   remains writable.
 * (py_test, py_binary) Allow external files to be used for main
+* (pypi) Correctly aggregate the sources when the hashes specified in the lockfile differ
+  by platform even though the same version is used. Fixes [#2648](https://github.com/bazel-contrib/rules_python/issues/2648).
 
 {#v0-0-0-added}
 ### Added

python/private/pypi/parse_requirements.bzl

@@ -223,7 +223,7 @@ def _package_srcs(
         env_marker_target_platforms,
         extract_url_srcs):
     """A function to return sources for a particular package."""
-    srcs = []
+    srcs = {}
     for r in sorted(reqs.values(), key = lambda r: r.requirement_line):
         whls, sdist = _add_dists(
             requirement = r,
@@ -249,21 +249,31 @@ def _package_srcs(
             )]
             req_line = r.srcs.requirement_line
 
+        extra_pip_args = tuple(r.extra_pip_args)
         for dist in all_dists:
-            srcs.append(
+            key = (
+                dist.filename,
+                req_line,
+                extra_pip_args,
+            )
+            entry = srcs.setdefault(
+                key,
                 struct(
                     distribution = name,
                     extra_pip_args = r.extra_pip_args,
                     requirement_line = req_line,
-                    target_platforms = target_platforms,
+                    target_platforms = [],
                     filename = dist.filename,
                     sha256 = dist.sha256,
                     url = dist.url,
                     yanked = dist.yanked,
                 ),
             )
+            for p in target_platforms:
+                if p not in entry.target_platforms:
+                    entry.target_platforms.append(p)
 
-    return srcs
+    return srcs.values()
 
 def select_requirement(requirements, *, platform):
     """A simple function to get a requirement for a particular platform.

tests/pypi/parse_requirements/parse_requirements_tests.bzl

@@ -38,7 +38,7 @@ foo[extra]==0.0.1 \
 foo @ git+https://github.com/org/foo.git@deadbeef
 """,
         "requirements_linux": """\
-foo==0.0.3 --hash=sha256:deadbaaf
+foo==0.0.3 --hash=sha256:deadbaaf --hash=sha256:5d15t
 """,
         # download_only = True
         "requirements_linux_download_only": """\
@@ -67,7 +67,7 @@ foo==0.0.4 @ https://example.org/foo-0.0.4.whl
 foo==0.0.5 @ https://example.org/foo-0.0.5.whl --hash=sha256:deadbeef
 """,
         "requirements_osx": """\
-foo==0.0.3 --hash=sha256:deadbaaf
+foo==0.0.3 --hash=sha256:deadbaaf --hash=sha256:deadb11f --hash=sha256:5d15t
 """,
         "requirements_osx_download_only": """\
 --platform=macosx_10_9_arm64
@@ -251,7 +251,7 @@ def _test_multi_os(env):
                 struct(
                     distribution = "foo",
                     extra_pip_args = [],
-                    requirement_line = "foo==0.0.3 --hash=sha256:deadbaaf",
+                    requirement_line = "foo==0.0.3 --hash=sha256:deadbaaf --hash=sha256:5d15t",
                     target_platforms = ["linux_x86_64"],
                     url = "",
                     filename = "",
@@ -515,6 +515,84 @@ def _test_git_sources(env):
 
 _tests.append(_test_git_sources)
 
+def _test_overlapping_shas_with_index_results(env):
+    got = parse_requirements(
+        ctx = _mock_ctx(),
+        requirements_by_platform = {
+            "requirements_linux": ["cp39_linux_x86_64"],
+            "requirements_osx": ["cp39_osx_x86_64"],
+        },
+        get_index_urls = lambda _, __: {
+            "foo": struct(
+                sdists = {
+                    "5d15t": struct(
+                        url = "sdist",
+                        sha256 = "5d15t",
+                        filename = "foo-0.0.1.tar.gz",
+                        yanked = False,
+                    ),
+                },
+                whls = {
+                    "deadb11f": struct(
+                        url = "super2",
+                        sha256 = "deadb11f",
+                        filename = "foo-0.0.1-py3-none-macosx_14_0_x86_64.whl",
+                        yanked = False,
+                    ),
+                    "deadbaaf": struct(
+                        url = "super2",
+                        sha256 = "deadbaaf",
+                        filename = "foo-0.0.1-py3-none-any.whl",
+                        yanked = False,
+                    ),
+                },
+            ),
+        },
+    )
+
+    env.expect.that_collection(got).contains_exactly([
+        struct(
+            name = "foo",
+            is_exposed = True,
+            # TODO @aignas 2025-05-25: how do we rename this?
+            is_multiple_versions = True,
+            srcs = [
+                struct(
+                    distribution = "foo",
+                    extra_pip_args = [],
+                    filename = "foo-0.0.1-py3-none-any.whl",
+                    requirement_line = "foo==0.0.3",
+                    sha256 = "deadbaaf",
+                    target_platforms = ["cp39_linux_x86_64", "cp39_osx_x86_64"],
+                    url = "super2",
+                    yanked = False,
+                ),
+                struct(
+                    distribution = "foo",
+                    extra_pip_args = [],
+                    filename = "foo-0.0.1.tar.gz",
+                    requirement_line = "foo==0.0.3",
+                    sha256 = "5d15t",
+                    target_platforms = ["cp39_linux_x86_64", "cp39_osx_x86_64"],
+                    url = "sdist",
+                    yanked = False,
+                ),
+                struct(
+                    distribution = "foo",
+                    extra_pip_args = [],
+                    filename = "foo-0.0.1-py3-none-macosx_14_0_x86_64.whl",
+                    requirement_line = "foo==0.0.3",
+                    sha256 = "deadb11f",
+                    target_platforms = ["cp39_osx_x86_64"],
+                    url = "super2",
+                    yanked = False,
+                ),
+            ],
+        ),
+    ])
+
+_tests.append(_test_overlapping_shas_with_index_results)
+
 def parse_requirements_test_suite(name):
     """Create the test suite.