From d369deaa40ffc5e84117d9f16c7c83f740b5939a Mon Sep 17 00:00:00 2001
From: Jace Browning <jacebrowning@gmail.com>
Date: Mon, 30 Mar 2020 21:13:38 -0400
Subject: [PATCH] Fix loading of missing nested dataclass attributes

---
 CHANGELOG.md                       |  4 ++++
 datafiles/converters/containers.py |  2 +-
 poetry.lock                        | 18 +++++++++---------
 pyproject.toml                     |  2 +-
 tests/test_instantiation.py        | 27 +++++++++++++++++++++++++--
 5 files changed, 40 insertions(+), 13 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05582739..6dd37bc2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 0.8.1 (2020-03-30)
+
+- Fixed loading of `Missing` nested dataclasses attributes.
+
 # 0.8 (2020-03-28)
 
 - Updated the `@datafile(...)` decorator to be used as a drop-in replacement for `@dataclass(...)`.
diff --git a/datafiles/converters/containers.py b/datafiles/converters/containers.py
index a69c264f..1e6099e2 100644
--- a/datafiles/converters/containers.py
+++ b/datafiles/converters/containers.py
@@ -159,7 +159,7 @@ def to_python_value(cls, deserialized_data, *, target_object):
 
         new_value = cls.DATACLASS(**data)  # pylint: disable=not-callable
 
-        if target_object is None:
+        if target_object is None or target_object is Missing:
             value = new_value
         else:
             value = target_object
diff --git a/poetry.lock b/poetry.lock
index 2c71118b..ec8668ad 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -499,7 +499,7 @@ description = "Minimalistic wrapper for Python logging."
 name = "minilog"
 optional = false
 python-versions = ">=3.6,<4.0"
-version = "1.4.1"
+version = "1.5"
 
 [[package]]
 category = "dev"
@@ -925,7 +925,7 @@ description = "Better testing with expecter and pytest."
 name = "pytest-expecter"
 optional = false
 python-versions = ">=3.6,<4.0"
-version = "2.0"
+version = "2.1"
 
 [[package]]
 category = "dev"
@@ -1212,7 +1212,7 @@ description = "Fast, Extensible Progress Meter"
 name = "tqdm"
 optional = false
 python-versions = ">=2.6, !=3.0.*, !=3.1.*"
-version = "4.44.0"
+version = "4.44.1"
 
 [package.extras]
 dev = ["py-make (>=0.1.0)", "twine", "argopt", "pydoc-markdown"]
@@ -1572,8 +1572,8 @@ mccabe = [
     {file = "mccabe-0.6.1.tar.gz", hash = "sha256:dd8d182285a0fe56bace7f45b5e7d1a6ebcbf524e8f3bd87eb0f125271b8831f"},
 ]
 minilog = [
-    {file = "minilog-1.4.1-py3-none-any.whl", hash = "sha256:b16be0ba7e5b2a1a10286b86e3ea1645f99ee4c5edfde97765a4f625654f2a64"},
-    {file = "minilog-1.4.1.tar.gz", hash = "sha256:ca695a822099e99d53b0528fc9b6ff12f483669dd3ce1796f0a5038be878a9cc"},
+    {file = "minilog-1.5-py3-none-any.whl", hash = "sha256:545cacd6a3db3b5b2fa9743acfc3c413c262ada2ea98ab6fe81a9ca56d4163f3"},
+    {file = "minilog-1.5.tar.gz", hash = "sha256:1670d6d2d28b0957ed1b89b4808c966127be118f989463cbcf3e7fb1335e427b"},
 ]
 mistune = [
     {file = "mistune-0.8.4-py2.py3-none-any.whl", hash = "sha256:88a1051873018da288eee8538d476dffe1262495144b33ecb586c4ab266bb8d4"},
@@ -1703,8 +1703,8 @@ pytest-describe = [
     {file = "pytest-describe-0.12.0.tar.gz", hash = "sha256:569bda96401fe512f4f345f33fd23fa4d718639d42afac62bc03254b5f2b3fdf"},
 ]
 pytest-expecter = [
-    {file = "pytest-expecter-2.0.tar.gz", hash = "sha256:cd73b4af7dc6f29ed55460036174c1f78b8c8cc24d8aed2f7db2eb446211643c"},
-    {file = "pytest_expecter-2.0-py3-none-any.whl", hash = "sha256:5fd076dad393eacf6588d8a2bc92dd73e447c7990904abb2c2572b6e913a3721"},
+    {file = "pytest-expecter-2.1.tar.gz", hash = "sha256:70b05fec2a9ae5ec6f15d5c5467c1e2cb9aa2fd85ec9c4783b26e2cf68e66f96"},
+    {file = "pytest_expecter-2.1-py3-none-any.whl", hash = "sha256:ab66120671a22be41f7df4c29d76c02d62e3420b8277b1455d2e683a042a0608"},
 ]
 pytest-mock = [
     {file = "pytest-mock-2.0.0.tar.gz", hash = "sha256:b35eb281e93aafed138db25c8772b95d3756108b601947f89af503f8c629413f"},
@@ -1885,8 +1885,8 @@ tornado = [
     {file = "tornado-6.0.4.tar.gz", hash = "sha256:0fe2d45ba43b00a41cd73f8be321a44936dc1aba233dee979f17a042b83eb6dc"},
 ]
 tqdm = [
-    {file = "tqdm-4.44.0-py2.py3-none-any.whl", hash = "sha256:f0fc945df434e5e612fb7eb93bf29e924940913590450c3760f198dd75a2cd19"},
-    {file = "tqdm-4.44.0.tar.gz", hash = "sha256:4f882b23c492e7060f50d83af86f163b67e4cfbe35dfe12077e748c56282f438"},
+    {file = "tqdm-4.44.1-py2.py3-none-any.whl", hash = "sha256:be5ddeec77d78ba781ea41eacb2358a77f74cc2407f54b82222d7ee7dc8c8ccf"},
+    {file = "tqdm-4.44.1.tar.gz", hash = "sha256:03d2366c64d44c7f61e74c700d9b202d57e9efe355ea5c28814c52bfe7a50b8c"},
 ]
 traitlets = [
     {file = "traitlets-4.3.3-py2.py3-none-any.whl", hash = "sha256:70b4c6a1d9019d7b4f6846832288f86998aa3b9207c6821f3578a6a6a467fe44"},
diff --git a/pyproject.toml b/pyproject.toml
index 75652480..9cd72c71 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [tool.poetry]
 
 name = "datafiles"
-version = "0.8"
+version = "0.8.1"
 description = "File-based ORM for dataclasses."
 
 license = "MIT"
diff --git a/tests/test_instantiation.py b/tests/test_instantiation.py
index c4128262..58ebb54b 100644
--- a/tests/test_instantiation.py
+++ b/tests/test_instantiation.py
@@ -4,8 +4,8 @@
 
 from dataclasses import dataclass, field
 
-from datafiles import datafile
-from datafiles.utils import write
+from datafiles import Missing, datafile
+from datafiles.utils import logbreak, write
 
 
 @datafile('../tmp/sample.yml', manual=True)
@@ -171,3 +171,26 @@ def when_file_exists(expect):
         expect(sample.a) == 1.2
         expect(sample.b) == 3.4
         expect(sample.c) == 9.9
+
+
+def describe_missing_attributes():
+    def when_dataclass(expect):
+        @dataclass
+        class Name:
+            value: str
+
+        @datafile("../tmp/samples/{self.key}.yml")
+        @dataclass
+        class Sample:
+
+            key: int
+            name: Name
+            value: float = 0.0
+
+        sample = Sample(42, Name("Widget"))
+
+        logbreak("Loading missing 'name' dataclass")
+
+        sample2 = Sample(42, Missing)  # type: ignore
+
+        expect(sample2.name.value) == "Widget"