feat(filter): add paths_include filter (#798)

NOTE: The paths_include filter provides a convenience filter for supporting includes on nested objects.

README.md

@@ -313,6 +313,16 @@ assert obj == snapshot(include=paths("nested", "nested.key"))
 
 The extra "nested" is required, otherwise the nested dictionary will never be searched -- it'd get pruned too early.
 
+To avoid adding duplicate path parts, we provide a convenient `paths_include` which supports a list/tuple instead of a string for each path to match:
+
+```py
+obj = {
+    "other": False,
+    "nested": { "key": True }
+}
+assert obj == snapshot(include=paths_include(["other"], ["nested", "key"]))
+```
+
 #### `extension_class`
 
 This is a way to modify how the snapshot matches and serializes your data in a single assertion.

src/syrupy/filters.py

@@ -1,4 +1,10 @@
-from typing import TYPE_CHECKING
+from typing import (
+    TYPE_CHECKING,
+    List,
+    Set,
+    Tuple,
+    Union,
+)
 
 if TYPE_CHECKING:
     from syrupy.types import (
@@ -8,24 +14,63 @@
     )
 
 
-def paths(path_string: str, *path_strings: str) -> "PropertyFilter":
+def paths(*path_parts: str) -> "PropertyFilter":
     """
-    Factory to create a filter using list of paths
+    Factory to create a filter using list of path strings.
+
+    This filter does not work well when combined with "include" and
+    nested paths, since "include" oeprates per key as an object is traversed
+    for serialization. For nested paths, we must include all parents. To accomplish
+    this, we provide an alternative "paths_include" filter which does this
+    automatically.
     """
 
+    if not path_parts:
+        raise TypeError("At least 1 path argument is required.")
+
+    parts: Set[str] = set(path_parts)
+
     def path_filter(*, prop: "PropertyName", path: "PropertyPath") -> bool:
         path_str = ".".join(str(p) for p, _ in (*path, (prop, None)))
-        return any(path_str == p for p in (path_string, *path_strings))
+        return path_str in parts
+
+    return path_filter
+
+
+def paths_include(*path_parts: Union[Tuple[str, ...], List[str]]) -> "PropertyFilter":
+    """
+    Factory to create a filter using list of path tuples.
+    """
+
+    if not path_parts:
+        raise TypeError("At least 1 path argument is required.")
+
+    # "include" operates per key as an object is traversed for serialization.
+    # This means, if matching a nested path, we must also include all parents.
+    parts: Set[Tuple[str, ...]] = set()
+    for path_part in path_parts:
+        if isinstance(path_part, (list, tuple)):
+            for idx in range(len(path_part)):
+                parts.add(tuple(path_part[: idx + 1]))
+        else:
+            raise TypeError("Unexpected argument. Expected list/tuple.")
+
+    def path_filter(*, prop: "PropertyName", path: "PropertyPath") -> bool:
+        path_tuple = tuple(str(p) for p, _ in (*path, (prop, None)))
+        return path_tuple in parts
 
     return path_filter
 
 
-def props(prop_name: str, *prop_names: str) -> "PropertyFilter":
+def props(*prop_names: str) -> "PropertyFilter":
     """
     Factory to create filter using list of props
     """
 
+    if not prop_names:
+        raise TypeError("At least 1 prop name is required.")
+
     def prop_filter(*, prop: "PropertyName", path: "PropertyPath") -> bool:
-        return any(str(prop) == p for p in (prop_name, *prop_names))
+        return any(str(prop) == p for p in prop_names)
 
     return prop_filter

tests/syrupy/extensions/amber/__snapshots__/test_amber_filters.ambr

@@ -35,6 +35,16 @@
     }),
   })
 # ---
+# name: test_includes_nested_path
+  dict({
+    'include-me': False,
+    'layer1': dict({
+      'layer2': list([
+        True,
+      ]),
+    }),
+  })
+# ---
 # name: test_only_includes_expected_props
   dict({
     'date': 'utc',

tests/syrupy/extensions/amber/test_amber_filters.py

@@ -4,12 +4,13 @@
 
 from syrupy.filters import (
     paths,
+    paths_include,
     props,
 )
 
 
 def test_filters_path_noop():
-    with pytest.raises(TypeError, match="required positional argument"):
+    with pytest.raises(TypeError, match="At least 1 path argument is required."):
         paths()
 
 
@@ -24,7 +25,7 @@ def test_filters_expected_paths(snapshot):
 
 
 def test_filters_prop_noop():
-    with pytest.raises(TypeError, match="required positional argument"):
+    with pytest.raises(TypeError, match="At least 1 prop name is required."):
         props()
 
 
@@ -50,6 +51,17 @@ def test_only_includes_expected_props(snapshot):
     assert actual == snapshot(include=paths("0", "date", "nested", "nested.id"))
 
 
+def test_includes_nested_path(snapshot):
+    actual = {
+        "ignore-me": True,
+        "include-me": False,
+        "layer1": {"layer2": [0, True]},
+    }
+    assert actual == snapshot(
+        include=paths_include(["include-me"], ["layer1", "layer2", "1"])
+    )
+
+
 @pytest.mark.parametrize(
     "predicate", [paths("exclude_me", "nested.exclude_me"), props("exclude_me")]
 )