Fixed pdm list output containing full license text in some cases

news/2538.bugfix.md

@@ -0,0 +1 @@
+Fixed pdm list output containing full license text in some cases

src/pdm/cli/commands/list.py

@@ -340,7 +340,15 @@ def __init__(self, dist: im.Distribution, groups: set[str]):
         # so generate a pipe separated list (to avoid complexity with CSV export).
         self.licenses: str | None = dist.metadata["License"]
         self.licenses = None if self.licenses == "UNKNOWN" else self.licenses
-        if not self.licenses:
+
+        # Sometimes package metadata contains the full license text.
+        # e.g. license = { file="LICENSE" } in pyproject.toml
+        # To identify this, check for newlines or very long strings.
+        # 50 chars is picked because the longest OSI license (WTFPL) full name is 43 characters.
+        is_full_text = self.licenses and "\n" in self.licenses or len(self.licenses or "") > 50
+
+        # If that is the case, look at the classifiers instead.
+        if not self.licenses or is_full_text:
             classifier_licenses = [v for v in dist.metadata.get_all("Classifier", []) if v.startswith("License")]
             alternatives = [parts.split("::") for parts in classifier_licenses]
             alternatives = [part[-1].strip() for part in alternatives if part]

tests/cli/test_list.py

@@ -513,8 +513,16 @@ class _MockPackagePath(pathlib.PurePosixPath):
         def read_text(self, *args, **kwargs):
             return self.license_text
 
-    # Foo package.
-    foo = Distribution("foo", "0.1.0", metadata={"License": "A License"})
+    # Foo package (adapted to contain newlines in License field)
+    # e.g. via license = { file="LICENSE" }
+    foo = Distribution(
+        "foo",
+        "0.1.0",
+        metadata={
+            "License": "A License\n\nextra\ntext",
+            "Classifier": "License :: A License",
+        },
+    )
     foo_l = _MockPackagePath("foo-0.1.0.dist-info", "LICENSE")
     foo_l.license_text = "license text for foo here"
     foo.files = [foo_l]
@@ -679,6 +687,9 @@ def test_list_json_fields_licences(project, pdm):
 
 @pytest.mark.usefixtures("fake_working_set")
 def test_list_markdown_fields_licences(project, pdm):
+    # Note that in "foo" the "License" metadata field ("License": "A License\n\nextra\ntext")
+    # is ignored, in favour of the classifier and the LICENSE file.
+    # This behaviour could be improved.
     result = pdm(["list", "--markdown", "--fields", "name,version,licenses"], obj=project)
     expected = (
         "# test-project licenses\n"