This commit fixes two issues with content filtering

-- `ZipContentFilter` logic for patterns that have a single allowed pattern.
   Earlier this would include all files.
-- `generate_content_hash` also considers the patterns before generating the
   hash so that the hash generated matches the content of the zip.

package.py

@@ -235,9 +235,20 @@ def emit_dir_content(base_dir):
             yield os.path.normpath(os.path.join(root, name))
 
 
-def generate_content_hash(source_paths, hash_func=hashlib.sha256, log=None):
+def generate_content_hash(
+    source_paths,
+    content_filter,
+    hash_func=hashlib.sha256,
+    log=None,
+):
     """
     Generate a content hash of the source paths.
+
+    :param content_filter: Callable[[str], Iterable[str]
+        A function that filters the content of the source paths. Given a path
+        to a file or directory, it should return an iterable of paths to files
+        that should be included in the hash. At present we pass in the
+        ZipContentFilter.filter method for this purpose.
     """
 
     if log:
@@ -248,8 +259,7 @@ def generate_content_hash(source_paths, hash_func=hashlib.sha256, log=None):
     for source_path in source_paths:
         if os.path.isdir(source_path):
             source_dir = source_path
-            _log = log if log.isEnabledFor(DEBUG3) else None
-            for source_file in list_files(source_dir, log=_log):
+            for source_file in content_filter(source_dir):
                 update_hash(hash_obj, source_dir, source_file)
                 if log:
                     log.debug(os.path.join(source_dir, source_file))
@@ -589,10 +599,8 @@ def apply(path):
                 op, regex = r
                 neg = op is operator.not_
                 m = regex.fullmatch(path)
-                if neg and m:
-                    d = False
-                elif m:
-                    d = True
+                m = bool(m)
+                d = not m if neg else m
             if d:
                 return path
 
@@ -648,6 +656,7 @@ class BuildPlanManager:
     def __init__(self, args, log=None):
         self._args = args
         self._source_paths = None
+        self._patterns = []
         self._log = log or logging.root
 
     def hash(self, extra_paths):
@@ -660,7 +669,11 @@ def hash(self, extra_paths):
         # runtime value, build command, and content of the build paths
         # because they can have an effect on the resulting archive.
         self._log.debug("Computing content hash on files...")
-        content_hash = generate_content_hash(content_hash_paths, log=self._log)
+        content_filter = ZipContentFilter(args=self._args)
+        content_filter.compile(self._patterns)
+        content_hash = generate_content_hash(
+            content_hash_paths, content_filter.filter, log=self._log
+        )
         return content_hash
 
     def plan(self, source_path, query):
@@ -800,7 +813,9 @@ def commands_step(path, commands):
                 patterns = claim.get("patterns")
                 commands = claim.get("commands")
                 if patterns:
-                    step("set:filter", patterns_list(self._args, patterns))
+                    patterns_as_list = patterns_list(self._args, patterns)
+                    self._patterns.extend(patterns_as_list)
+                    step("set:filter", patterns_as_list)
                 if commands:
                     commands_step(path, commands)
                 else:

tests/test_zip_source.py

@@ -1,7 +1,10 @@
 import os
+from pathlib import Path
 from unittest.mock import MagicMock, Mock
 
-from package import BuildPlanManager
+import pytest
+
+from package import BuildPlanManager, ZipContentFilter, datatree
 
 
 def test_zip_source_path_sh_work_dir():
@@ -44,3 +47,75 @@ def test_zip_source_path():
 
     zip_source_path = zs.write_dirs.call_args_list[0][0][0]
     assert zip_source_path == f"{os.getcwd()}"
+
+
+@pytest.fixture
+def source_path(tmp_path: str) -> Path:
+    """Creates a tmp stage dir for running tests."""
+    tmp_path = Path(tmp_path)
+    source = tmp_path / "some_dir"
+    source.mkdir()
+    for files in ["file.py", "file2.py", "README.md", "requirements.txt"]:
+        (source / files).touch()
+    yield source
+
+
+def test_zip_content_filter(source_path: Path):
+    """Test the zip content filter does not take all positive."""
+    args = Mock()
+    query_data = {
+        "runtime": "python",
+        "source_path": {
+            "path": str(source_path),
+            "patterns": [".*.py$"],
+        },
+    }
+    query = datatree("prepare_query", **query_data)
+
+    file_filter = ZipContentFilter(args=args)
+    file_filter.compile(query.source_path.patterns)
+    filtered = list(file_filter.filter(query.source_path.path))
+    expected = [str(source_path / fname) for fname in ["file.py", "file2.py"]]
+    assert filtered == sorted(expected)
+
+    # Test that filtering with empty patterns returns all files.
+    file_filter = ZipContentFilter(args=args)
+    file_filter.compile([])
+    filtered = list(file_filter.filter(query.source_path.path))
+    expected = [
+        str(source_path / fname)
+        for fname in ["file.py", "file2.py", "README.md", "requirements.txt"]
+    ]
+    assert filtered == sorted(expected)
+
+
+def test_generate_hash(source_path: Path):
+    """Tests prepare hash generation and also packaging."""
+    args = Mock()
+
+    query_data = {
+        "runtime": "python",
+        "source_path": {
+            "path": str(source_path),
+            "patterns": ["!.*", ".*.py$"],
+        },
+    }
+    query = datatree("prepare_query", **query_data)
+
+    bpm = BuildPlanManager(args)
+    bpm.plan(query.source_path, query)
+    hash1 = bpm.hash([]).hexdigest()
+
+    # Add a new file that does not match the pattern.
+    (source_path / "file3.pyc").touch()
+    bpm.plan(query.source_path, query)
+    hash2 = bpm.hash([]).hexdigest()
+    # Both hashes should still be the same.
+    assert hash1 == hash2
+
+    # Add a new file that does match the pattern.
+    (source_path / "file4.py").touch()
+    bpm.plan(query.source_path, query)
+    hash3 = bpm.hash([]).hexdigest()
+    # Hash should be different.
+    assert hash1 != hash3