Add test_prefix_files (#5260)

conda_build/utils.py

@@ -1784,22 +1784,24 @@ def merge_dicts_of_lists(
     return {k: dol1.get(k, no) + dol2.get(k, no) for k in keys}
 
 
-def prefix_files(prefix):
+def prefix_files(prefix: str | os.PathLike | Path) -> set[str]:
     """
     Returns a set of all files in prefix.
     """
-    res = set()
-    prefix_rep = prefix + os.path.sep
-    for root, dirs, files in walk(prefix):
-        for fn in files:
-            # this is relpath, just hacked to be faster
-            res.add(join(root, fn).replace(prefix_rep, "", 1))
-        for dn in dirs:
-            path = join(root, dn)
-            if islink(path):
-                res.add(path.replace(prefix_rep, "", 1))
-                res.update(expand_globs((path,), prefix))
-    return res
+    prefix = f"{os.path.abspath(prefix)}{os.path.sep}"
+    prefix_files: set[str] = set()
+    for root, directories, files in walk(prefix):
+        # this is effectively os.path.relpath, just hacked to be faster
+        relroot = root[len(prefix) :].lstrip(os.path.sep)
+        # add all files
+        prefix_files.update(join(relroot, file) for file in files)
+        # add all symlink directories (they are "files")
+        prefix_files.update(
+            join(relroot, directory)
+            for directory in directories
+            if islink(join(root, directory))
+        )
+    return prefix_files
 
 
 def mmap_mmap(

tests/test_utils.py

@@ -433,3 +433,25 @@ def test_is_conda_pkg(tmpdir, value: str, expected: bool, is_dir: bool, create:
                 fp.write("test")
 
     assert utils.is_conda_pkg(value) == expected
+
+
+def test_prefix_files(tmp_path: Path):
+    # all files within the prefix are found
+    (prefix := tmp_path / "prefix1").mkdir()
+    (file1 := prefix / "file1").touch()
+    (dirA := prefix / "dirA").mkdir()
+    (file2 := dirA / "file2").touch()
+    (dirB := prefix / "dirB").mkdir()
+    (file3 := dirB / "file3").touch()
+
+    # files outside of the prefix are not found
+    (prefix2 := tmp_path / "prefix2").mkdir()
+    (prefix2 / "file4").touch()
+    (dirC := prefix2 / "dirC").mkdir()
+    (dirC / "file5").touch()
+
+    # even if they are symlinked
+    (link1 := prefix / "dirC").symlink_to(dirC)
+
+    paths = {str(path.relative_to(prefix)) for path in (file1, file2, file3, link1)}
+    assert paths == utils.prefix_files(str(prefix))