From 3137990937ca8912c1cf7ced6a5450819ffa2e57 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Randy=20D=C3=B6ring?=
 <30527984+radoering@users.noreply.github.com>
Date: Sun, 3 Jul 2022 15:22:26 +0200
Subject: [PATCH] Add explanatory comment and tests

---
 src/poetry/core/packages/dependency.py |  5 +++++
 tests/packages/test_dependency.py      | 28 ++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/src/poetry/core/packages/dependency.py b/src/poetry/core/packages/dependency.py
index 8715c27d6..bbf3a1dee 100644
--- a/src/poetry/core/packages/dependency.py
+++ b/src/poetry/core/packages/dependency.py
@@ -574,6 +574,11 @@ def __eq__(self, other: object) -> bool:
         if not isinstance(other, Dependency):
             return NotImplemented
 
+        # "constraint" is implicitly given for direct origin dependencies and might not
+        # be set yet ("*"). Thus, it shouldn't be used to determine if two direct origin
+        # dependencies are equal.
+        # Calling is_direct_origin() for one dependency is sufficient because
+        # super().__eq__() returns False for different origins.
         return super().__eq__(other) and (
             self._constraint == other.constraint or self.is_direct_origin()
         )
diff --git a/tests/packages/test_dependency.py b/tests/packages/test_dependency.py
index 5089632e9..a64e641f9 100644
--- a/tests/packages/test_dependency.py
+++ b/tests/packages/test_dependency.py
@@ -361,6 +361,34 @@ def test_create_from_pep_508_url_with_activated_extras() -> None:
     assert dependency.extras == {"fred", "bar"}
 
 
+@pytest.mark.parametrize(
+    "dependency1, dependency2, expected",
+    [
+        (Dependency("a", "1.0"), Dependency("a", "1.0"), True),
+        (Dependency("a", "1.0"), Dependency("a", "1.0.1"), False),
+        (Dependency("a", "1.0"), Dependency("a1", "1.0"), False),
+        (Dependency("a", "1.0"), Dependency("a", "1.0", source_type="file"), False),
+        # constraint is implicitly given for direct origin dependencies,
+        # but might not be set
+        (
+            Dependency("a", "1.0", source_type="file"),
+            Dependency("a", "*", source_type="file"),
+            True,
+        ),
+        # constraint is not implicit for non direct origin dependencies
+        (Dependency("a", "1.0"), Dependency("a", "*"), False),
+        (
+            Dependency("a", "1.0", source_type="legacy"),
+            Dependency("a", "*", source_type="legacy"),
+            False,
+        ),
+    ],
+)
+def test_eq(dependency1: Dependency, dependency2: Dependency, expected: bool) -> None:
+    assert (dependency1 == dependency2) is expected
+    assert (dependency2 == dependency1) is expected
+
+
 @pytest.mark.parametrize(
     "attr_name, value",
     [