From 325b2111d6a5a16658943ac6f7250f76dace45fd Mon Sep 17 00:00:00 2001
From: Sheng Yu <sheng.yu@canonical.com>
Date: Tue, 4 Jul 2023 15:52:27 -0400
Subject: [PATCH] config: allow bundle without metadata.yaml

---
 charmcraft/models/charmcraft.py | 45 +++++++++++++++++++--------------
 tests/commands/test_build.py    |  6 ++---
 tests/test_models.py            |  8 +++---
 3 files changed, 32 insertions(+), 27 deletions(-)

diff --git a/charmcraft/models/charmcraft.py b/charmcraft/models/charmcraft.py
index 05e6989c8..93490ba91 100644
--- a/charmcraft/models/charmcraft.py
+++ b/charmcraft/models/charmcraft.py
@@ -117,9 +117,9 @@ class CharmcraftConfig(
     metadata_legacy: bool = False
 
     type: str
-    name: pydantic.StrictStr
-    summary: pydantic.StrictStr
-    description: pydantic.StrictStr
+    name: Optional[pydantic.StrictStr]
+    summary: Optional[pydantic.StrictStr]
+    description: Optional[pydantic.StrictStr]
     charmhub: CharmhubConfig = CharmhubConfig()
     parts: Optional[Dict[str, Any]]
     bases: Optional[List[BasesConfiguration]]
@@ -150,11 +150,27 @@ def validate_charm_type(cls, charm_type):
     @pydantic.validator("name", pre=True, always=True)
     def validate_name(cls, name, values):
         """Verify charm name is valid with exception when instantiated without YAML."""
-        if not name:
-            raise ValueError("value must not be empty")
+        if values.get("type") == "charm" and not name:
+            raise ValueError("needs value")
 
         return name
 
+    @pydantic.validator("summary", pre=True, always=True)
+    def validate_summary(cls, summary, values):
+        """Verify charm summary is valid with exception when instantiated without YAML."""
+        if values.get("type") == "charm" and not summary:
+            raise ValueError("needs value")
+
+        return summary
+
+    @pydantic.validator("description", pre=True, always=True)
+    def validate_description(cls, description, values):
+        """Verify charm name is valid with exception when instantiated without YAML."""
+        if values.get("type") == "charm" and not description:
+            raise ValueError("needs value")
+
+        return description
+
     @pydantic.validator("parts", pre=True, always=True)
     def validate_special_parts(cls, parts, values):
         """Verify parts type (craft-parts will re-validate the schemas for the plugins)."""
@@ -313,31 +329,22 @@ def unmarshal(cls, obj: Dict[str, Any], project: Project):
                         }
                     )
                 elif obj.get("type") == "bundle":
-                    # only need name from bundle,
-                    # metadata.yaml will be copied without validation
+                    # bundle may not have metadata.yaml.
+                    # but if it does, it should have name and optional description
+                    # metadata.yaml will be copied without validation if it exists
                     metadata_legacy = parse_bundle_metadata_yaml(project.dirpath)
                     return cls.parse_obj(
                         {
                             "project": project,
                             "name": metadata_legacy.name,
-                            "summary": "",
-                            "description": metadata_legacy.description or "",
+                            "description": metadata_legacy.description,
                             "metadata-legacy": True,
                             **obj,
                         }
                     )
                 else:
                     # fallthrough for pydantic to handle
-                    return cls.parse_obj(
-                        {
-                            "project": project,
-                            "name": "invalid-type",
-                            "summary": "",
-                            "description": "",
-                            "metadata-legacy": True,
-                            **obj,
-                        }
-                    )
+                    pass
 
             return cls.parse_obj({"project": project, **obj})
         except pydantic.error_wrappers.ValidationError as error:
diff --git a/tests/commands/test_build.py b/tests/commands/test_build.py
index 8913b8cb0..47ac40fd1 100644
--- a/tests/commands/test_build.py
+++ b/tests/commands/test_build.py
@@ -245,9 +245,9 @@ def test_build_error_without_metadata_yaml(basic_project):
     assert str(exc_info.value) == dedent(
         """\
         Bad charmcraft.yaml content:
-        - field 'name' required in top-level configuration
-        - field 'summary' required in top-level configuration
-        - field 'description' required in top-level configuration"""
+        - needs value in field 'name'
+        - needs value in field 'summary'
+        - needs value in field 'description'"""
     )
 
 
diff --git a/tests/test_models.py b/tests/test_models.py
index 152c06563..50f2fc7c7 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -95,7 +95,7 @@ def test_load_minimal_metadata_from_charmcraft_yaml_missing_name(
         )
     )
 
-    with pytest.raises(CraftError, match="field 'name' required in top-level configuration"):
+    with pytest.raises(CraftError, match="needs value in field 'name'"):
         load(tmp_path)
 
 
@@ -139,7 +139,7 @@ def test_load_minimal_metadata_from_charmcraft_yaml_missing_summary(
         ),
     )
 
-    with pytest.raises(CraftError, match="field 'summary' required in top-level configuration"):
+    with pytest.raises(CraftError, match="needs value in field 'summary'"):
         load(tmp_path)
 
 
@@ -161,9 +161,7 @@ def test_load_minimal_metadata_from_charmcraft_yaml_missing_description(
         ),
     )
 
-    with pytest.raises(
-        CraftError, match="field 'description' required in top-level configuration"
-    ):
+    with pytest.raises(CraftError, match="needs value in field 'description'"):
         load(tmp_path)