Generate PEP 440 direct reference whenever possible

piptools/utils.py

@@ -14,6 +14,7 @@
     Tuple,
     TypeVar,
     Union,
+    cast,
 )
 
 import click
@@ -115,14 +116,7 @@ def format_requirement(
     if ireq.editable:
         line = f"-e {ireq.link.url}"
     elif is_url_requirement(ireq):
-        if ireq.name:
-            line = (
-                ireq.link.url
-                if ireq.link.egg_fragment
-                else f"{ireq.name.lower()} @ {ireq.link.url}"
-            )
-        else:
-            line = ireq.link.url
+        line = _build_direct_reference_best_efforts(ireq)
     else:
         line = str(ireq.req).lower()
 
@@ -136,6 +130,38 @@ def format_requirement(
     return line
 
 
+def _build_direct_reference_best_efforts(ireq: InstallRequirement) -> str:
+    """
+    Returns a string of a direct reference URI, whenever possible.
+    See https://www.python.org/dev/peps/pep-0508/
+    """
+    # If the requirement has no name then we cannot build a direct reference.
+    if not ireq.name:
+        return cast(str, ireq.link.url)
+
+    # Look for a relative file path, the direct reference currently does not work with it.
+    if ireq.link.is_file and not ireq.link.path.startswith("/"):
+        return cast(str, ireq.link.url)
+
+    # If we get here then we have a requirement that supports direct reference.
+    # We need to remove the egg if it exists and keep the rest of the fragments.
+    direct_reference = f"{ireq.name.lower()} @ {ireq.link.url_without_fragment}"
+    fragments = []
+
+    # Check if there is any fragment to add to the URI.
+    if ireq.link.subdirectory_fragment:
+        fragments.append(f"subdirectory={ireq.link.subdirectory_fragment}")
+
+    if ireq.link.has_hash:
+        fragments.append(f"{ireq.link.hash_name}={ireq.link.hash}")
+
+    # Then add the fragments into the URI, if any.
+    if fragments:
+        direct_reference += f"#{'&'.join(fragments)}"
+
+    return direct_reference
+
+
 def format_specifier(ireq: InstallRequirement) -> str:
     """
     Generic formatter for pretty printing the specifier part of

tests/test_cli_compile.py

@@ -537,8 +537,8 @@ def test_locally_available_editable_package_is_not_archived_in_cache_dir(
             "pytest-django @ git+git://github.com/pytest-dev/pytest-django"
             "@21492afc88a19d4ca01cd0ac392a5325b14f95c7"
             "#egg=pytest-django",
-            "git+git://github.com/pytest-dev/pytest-django"
-            "@21492afc88a19d4ca01cd0ac392a5325b14f95c7#egg=pytest-django",
+            "pytest-django @ git+git://github.com/pytest-dev/pytest-django"
+            "@21492afc88a19d4ca01cd0ac392a5325b14f95c7",
             id="VCS with direct reference and egg",
         ),
     ),
@@ -607,9 +607,12 @@ def test_url_package(runner, line, dependency, generate_hashes):
         pytest.param(
             path_to_url(os.path.join(PACKAGES_PATH, "small_fake_with_subdir"))
             + "#subdirectory=subdir&egg=small_fake_a",
-            path_to_url(os.path.join(PACKAGES_PATH, "small_fake_with_subdir"))
-            + "#subdirectory=subdir&egg=small_fake_a",
-            None,
+            "small-fake-a @ "
+            + path_to_url(os.path.join(PACKAGES_PATH, "small_fake_with_subdir"))
+            + "#subdirectory=subdir",
+            "small-fake-a @ "
+            + path_to_url(os.path.join(PACKAGES_PATH, "small_fake_with_subdir"))
+            + "#subdirectory=subdir",
             id="Local project with subdirectory",
         ),
     ),
@@ -843,8 +846,8 @@ def test_generate_hashes_with_url(runner):
         )
     out = runner.invoke(cli, ["--no-annotate", "--generate-hashes"])
     expected = (
-        "https://github.com/jazzband/pip-tools/archive/"
-        "7d86c8d3ecd1faa6be11c7ddc6b29a30ffd1dae3.zip#egg=pip-tools \\\n"
+        "pip-tools @ https://github.com/jazzband/pip-tools/archive/"
+        "7d86c8d3ecd1faa6be11c7ddc6b29a30ffd1dae3.zip \\\n"
         "    --hash=sha256:d24de92e18ad5bf291f25cfcdcf"
         "0171be6fa70d01d0bef9eeda356b8549715e7\n"
     )

tests/test_utils.py

@@ -52,48 +52,72 @@ def test_format_requirement(from_line):
         ),
         pytest.param(
             "example @ https://example.com/example.zip#egg=example",
-            "https://example.com/example.zip#egg=example",
-            id="url with egg in fragment",
+            "example @ https://example.com/example.zip",
+            id="direct reference with egg in fragment",
         ),
         pytest.param(
             "example @ https://example.com/example.zip#subdirectory=test&egg=example",
-            "https://example.com/example.zip#subdirectory=test&egg=example",
-            id="url with subdirectory and egg in fragment",
+            "example @ https://example.com/example.zip#subdirectory=test",
+            id="direct reference with subdirectory and egg in fragment",
+        ),
+        pytest.param(
+            "example @ https://example.com/example.zip#subdirectory=test"
+            "&egg=example&sha1=594b7dd32bec37d8bf70a6ffa8866d30e93f3c42",
+            "example @ https://example.com/example.zip#subdirectory=test"
+            "&sha1=594b7dd32bec37d8bf70a6ffa8866d30e93f3c42",
+            id="direct reference with subdirectory, hash and egg in fragment",
         ),
         pytest.param(
-            "example @ https://example.com/example.zip?egg=test#subdirectory=project_a",
-            "example @ https://example.com/example.zip?egg=test#subdirectory=project_a",
-            id="url with egg in query",
+            "example @ https://example.com/example.zip?egg=test",
+            "example @ https://example.com/example.zip?egg=test",
+            id="direct reference with egg in query",
         ),
         pytest.param(
             "file:./vendor/package.zip",
             "file:./vendor/package.zip",
-            id="relative path",
+            id="file scheme relative path",
         ),
         pytest.param(
             "file:vendor/package.zip",
             "file:vendor/package.zip",
-            id="relative path",
+            id="file scheme relative path",
         ),
         pytest.param(
             "file:vendor/package.zip#egg=example",
             "file:vendor/package.zip#egg=example",
-            id="relative path with egg",
+            id="file scheme relative path with egg",
+        ),
+        pytest.param(
+            "file:./vendor/package.zip#egg=example",
+            "file:./vendor/package.zip#egg=example",
+            id="file scheme relative path with egg",
         ),
         pytest.param(
             "file:///vendor/package.zip",
             "file:///vendor/package.zip",
-            id="full path without direct reference",
+            id="file scheme absolute path without direct reference",
+        ),
+        pytest.param(
+            "file:///vendor/package.zip#egg=test",
+            "test @ file:///vendor/package.zip",
+            id="file scheme absolute path with egg",
         ),
         pytest.param(
             "package @ file:///vendor/package.zip",
             "package @ file:///vendor/package.zip",
-            id="full path with direct reference",
+            id="file scheme absolute path with direct reference",
         ),
         pytest.param(
             "package @ file:///vendor/package.zip#egg=example",
-            "file:///vendor/package.zip#egg=example",
-            id="full path with direct reference and egg",
+            "package @ file:///vendor/package.zip",
+            id="file scheme absolute path with direct reference and egg",
+        ),
+        pytest.param(
+            "package @ file:///vendor/package.zip#egg=example&subdirectory=test"
+            "&sha1=594b7dd32bec37d8bf70a6ffa8866d30e93f3c42",
+            "package @ file:///vendor/package.zip#subdirectory=test"
+            "&sha1=594b7dd32bec37d8bf70a6ffa8866d30e93f3c42",
+            id="full path with direct reference, egg, subdirectory and hash",
         ),
     ),
 )

tests/test_writer.py

@@ -152,7 +152,7 @@ def test_iter_lines__hash_missing(capsys, writer, from_line):
 
     expected_lines = (
         MESSAGE_UNHASHED_PACKAGE,
-        "file:///example/#egg=example",
+        "example @ file:///example/",
         "test==1.2 \\\n    --hash=FAKEHASH",
     )
     assert tuple(lines) == expected_lines
@@ -177,8 +177,8 @@ def test_iter_lines__no_warn_if_only_unhashable_packages(writer, from_line):
     lines = writer._iter_lines(ireqs, hashes=hashes)
 
     expected_lines = (
-        "file:///unhashable-pkg1/#egg=unhashable-pkg1",
-        "file:///unhashable-pkg2/#egg=unhashable-pkg2",
+        "unhashable-pkg1 @ file:///unhashable-pkg1/",
+        "unhashable-pkg2 @ file:///unhashable-pkg2/",
     )
     assert tuple(lines) == expected_lines