Add CoverageJSON TypeAdapter to support generic loading of CoverageJSON

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12']
 
     steps:
       - uses: actions/checkout@v4

README.md

@@ -34,6 +34,8 @@ pip install git+https://github.com/KNMI/covjson-pydantic.git
 
 ## Usage
 
+### Generating CovJSON
+
 ```python
 from datetime import datetime, timezone
 from pydantic import AwareDatetime
@@ -104,6 +106,36 @@ Will print
 }
 ```
 
+### Validating CovJSON
+
+There is a helper `TypeAdapter` called `CoverageJSON` that will validate any (supported) CoverageJSON input, and
+return the corresponding model. These can be of the type `CoverageCollection`, `Coverage`, `Domain`, `TiledNdArray`
+or `NdArray`.
+
+```python
+from covjson_pydantic.coverage import CoverageJSON
+covjson = CoverageJSON.validate_json("""
+{
+    "type": "NdArray",
+    "dataType": "float",
+    "axisNames": [
+        "t",
+        "y",
+        "x"
+    ],
+    "shape": [
+        1,
+        1,
+        1
+    ],
+    "values": [
+        27.1
+    ]
+}
+""")
+print(type(covjson))
+```
+
 ## Contributing
 
 Make an editable installation from within the repository root

example.py

@@ -2,6 +2,7 @@
 from datetime import timezone
 
 from covjson_pydantic.coverage import Coverage
+from covjson_pydantic.coverage import CoverageJSON
 from covjson_pydantic.domain import Axes
 from covjson_pydantic.domain import Domain
 from covjson_pydantic.domain import DomainType
@@ -22,3 +23,26 @@
 )
 
 print(c.model_dump_json(exclude_none=True, indent=4))
+
+covjson = CoverageJSON.validate_json(
+    """
+{
+    "type": "NdArray",
+    "dataType": "float",
+    "axisNames": [
+        "t",
+        "y",
+        "x"
+    ],
+    "shape": [
+        1,
+        1,
+        1
+    ],
+    "values": [
+        27.1
+    ]
+}
+"""
+)
+print(type(covjson))

src/covjson_pydantic/coverage.py

@@ -1,16 +1,19 @@
+from typing import Annotated
 from typing import Dict
 from typing import List
 from typing import Literal
 from typing import Optional
 from typing import Union
 
+from covjson_pydantic.domain import Domain
+from covjson_pydantic.ndarray import NdArray
+from covjson_pydantic.ndarray import TiledNdArray
 from pydantic import AnyUrl
+from pydantic import Field
+from pydantic import TypeAdapter
 
 from .base_models import CovJsonBaseModel
-from .domain import Domain
 from .domain import DomainType
-from .ndarray import NdArray
-from .ndarray import TiledNdArray
 from .parameter import Parameter
 from .parameter import ParameterGroup
 from .reference_system import ReferenceSystemConnectionObject
@@ -32,3 +35,12 @@ class CoverageCollection(CovJsonBaseModel, extra="allow"):
     parameters: Optional[Dict[str, Parameter]] = None
     parameterGroups: Optional[List[ParameterGroup]] = None  # noqa: N815
     referencing: Optional[List[ReferenceSystemConnectionObject]] = None
+
+
+# type: Union[CoverageCollection, Coverage, Domain, TiledNdArray, NdArray]
+CoverageJSON = TypeAdapter(
+    Annotated[
+        Union[CoverageCollection, Coverage, Domain, TiledNdArray, NdArray],
+        Field(discriminator="type"),
+    ]
+)

tests/test_coverage.py

@@ -4,6 +4,7 @@
 import pytest
 from covjson_pydantic.coverage import Coverage
 from covjson_pydantic.coverage import CoverageCollection
+from covjson_pydantic.coverage import CoverageJSON
 from covjson_pydantic.domain import Axes
 from covjson_pydantic.domain import Domain
 from covjson_pydantic.ndarray import NdArray
@@ -76,3 +77,12 @@ def test_error_cases(file_name, object_type, error_message):
 
     with pytest.raises(ValidationError, match=error_message):
         object_type.model_validate_json(json_string)
+
+
+def test_covjson_type_adapter():
+    file = Path(__file__).parent.resolve() / "test_data" / "coverage-json.json"
+    # Put JSON in default unindented format
+    with open(file, "r") as f:
+        o = CoverageJSON.validate_json(f.read())
+
+    assert isinstance(o, Coverage)