metadata.preview is now polymorphic

docs/source/schema.md

@@ -38,7 +38,6 @@ It's a json object with the following keys :
     "BPM": 120.0,
     "offset": 0.0,
     "preview": {},
-    "preview path": "",
 }
 ```
 Contains information that applies to the whole set of charts
@@ -60,11 +59,8 @@ Contains information that applies to the whole set of charts
     - number, required
     - In seconds, opposite of the time position of the first beat in the music file. For instance, if the first beat occurs at 0.15 seconds in the audio file, `offset̀` should be -0.15
 - **preview**
-    - object, optional
-    - If present, contains a {ref}`preview object <preview>`
-- **preview path**
-    - string, optional
-    - Path to a preview file to be played on loop at the music select screen. Alternative to the music sample described by `preview`.
+    - object or string, optional
+    - Contains either a {ref}`preview object <preview>` or a path to a bms-style preview file
 
 (preview)=
 ## Preview

schema.json

@@ -39,24 +39,28 @@
                 },
                 "preview": {
                     "description": "Describes the part of the music file that's to be played on loop when previewing this song",
-                    "type": "object",
-                    "properties": {
-                        "position": {
-                            "description": "In seconds, Time at which preview should start",
-                            "type": "number",
-                            "minimum": 0
+                    "oneOf": [{
+                            "description": "Preview defined as a sample from the music file",
+                            "type": "object",
+                            "properties": {
+                                "position": {
+                                    "description": "In seconds, Time at which preview should start",
+                                    "type": "number",
+                                    "minimum": 0
+                                },
+                                "length": {
+                                    "description": "In seconds, for how long should the preview be played past the starting point",
+                                    "type": "number",
+                                    "minimum": 0
+                                }
+                            },
+                            "required": ["position", "length"]
                         },
-                        "length": {
-                            "description": "In seconds, for how long should the preview be played past the starting point",
-                            "type": "number",
-                            "minimum": 0
+                        {
+                            "description": "Preview defined as a separate audio file",
+                            "type": "string"
                         }
-                    },
-                    "required": ["position", "length"]
-                },
-                "preview path": {
-                    "description": "Path to the music preview, relative to the memon file",
-                    "type": "string"
+                    ]
                 }
             },
             "required": ["song title", "artist", "BPM", "offset"]
@@ -92,7 +96,7 @@
                                 },
                                 "t": {
                                     "description": "Timing, measured in \"ticks\" as specified with the resolution",
-                                    "type":"integer",
+                                    "type": "integer",
                                     "minimum": 0
                                 },
                                 "l": {

tests/conftest.py

@@ -0,0 +1,67 @@
+
+import json
+from functools import partial
+from pathlib import Path
+from typing import Any
+
+import py.path
+import pytest
+from jschon import create_catalog, JSON, JSONSchema, Catalog
+
+from .utils import raise_if_invalid, result_of
+
+
+def pytest_collect_file(path: py.path.local, parent: pytest.Collector):
+    fspath = Path(path)
+    if fspath.name == "__init__.py" and fspath.parent.name == "data":
+        return ExamplesFolder.from_parent(parent, name="data", fspath=path.dirpath())
+
+
+class ExamplesFolder(pytest.Collector):
+    def collect(self):
+        path = Path(self.fspath)
+        for thing in path.glob("*-*"):
+            if thing.is_dir():
+                yield ExampleSubfolder.from_parent(
+                    self,
+                    name=thing.name,
+                    fspath=py.path.local(thing),
+                )
+
+
+class ExampleSubfolder(pytest.Collector):
+    def collect(self):
+        path = Path(self.fspath)
+        for file in (path / "pass").glob("*.json"):
+            yield ValidExample.from_parent(self, name=file.stem, path=file)
+        
+        for file in (path / "fail").glob("*.json"):
+            yield InvalidExample.from_parent(self, name=file.stem, path=file)
+
+
+class ItemWithPath(pytest.Item):
+    def __init__(self, *a, path: Path, **kw):
+        super().__init__(*a, **kw)
+        self.path = path
+
+    def reportinfo(self):
+        return self.path, 0, "" 
+
+
+class ValidExample(ItemWithPath):
+    def runtest(self):
+        raise_if_invalid(result_of(self.path))
+    
+    def repr_failure(self, excinfo):
+        parent = self.getparent(ExampleSubfolder)
+        return f"Example {parent.name}::{self.name} did not pass validation"
+
+
+class InvalidExample(ItemWithPath):
+    def runtest(self):
+        with pytest.raises(RuntimeError):
+            raise_if_invalid(result_of(self.path))
+
+    def repr_failure(self, excinfo):
+        parent = self.getparent(ExampleSubfolder)
+        return f"Example {parent.name}::{self.name} passed validation but shouldn't"

tests/data/01-basic/pass/basic.json

@@ -0,0 +1,10 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0
+    },
+    "data": {}
+}

tests/data/02-polymorphic-preview/fail/array-is-invalid.json

@@ -0,0 +1,11 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": []
+    },
+    "data": {}
+}

tests/data/02-polymorphic-preview/fail/invalid-object.json

@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": {
+            "position": 0,
+            "duration": 0
+        }
+    },
+    "data": {}
+}

tests/data/02-polymorphic-preview/fail/null-is-invalid.json

@@ -0,0 +1,11 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": null
+    },
+    "data": {}
+}

tests/data/02-polymorphic-preview/fail/number-is-invalid.json

@@ -0,0 +1,11 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": 3
+    },
+    "data": {}
+}

tests/data/02-polymorphic-preview/pass/valid-object.json

@@ -0,0 +1,14 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": {
+            "position": 0,
+            "length": 0
+        }
+    },
+    "data": {}
+}

tests/data/02-polymorphic-preview/pass/valid-string.json

@@ -0,0 +1,11 @@
+{
+    "version": "1.0.0",
+    "metadata": {
+        "song title": "",
+        "artist": "",
+        "BPM": 1,
+        "offset": 0,
+        "preview": "blablabla"
+    },
+    "data": {}
+}

tests/data/__init__.py

@@ -0,0 +1,2 @@
+"""This file is here so the test code can use importlib as a portable way to
+open test data in this folder"""

tests/test_schema.py

@@ -1,10 +1,7 @@
-import json
-from jschon import create_catalog, JSONSchema
+from jschon import JSONSchema
+
+from .utils import raise_if_invalid, SCHEMA
 
 def test_that_the_schema_follows_the_metaschema():
-    catalog_2019_09 = create_catalog("2019-09", default=True)
-    with open("schema.json") as file:
-        raw = json.load(file)
-    schema = JSONSchema(raw, catalog=catalog_2019_09)
-    schema.validate()
-
+    schema_validity = SCHEMA.validate()
+    raise_if_invalid(schema_validity)

tests/utils.py

@@ -0,0 +1,45 @@
+import json
+from collections import defaultdict
+from pathlib import Path
+from typing import Iterator, Dict, Tuple, List
+
+from jschon.jsonschema import Scope
+from jschon import create_catalog, JSONSchema, JSON
+import pytest
+
+_catalog = create_catalog('2019-09')
+SCHEMA = JSONSchema.loadf("schema.json", catalog=_catalog)
+
+def prettify_path(json_path: str) -> str:
+    """turns a JSONPath /that/looks/like/this into a.dotted.path.like.this"""
+    split = json_path.split("/")
+    return ".".join(split[1:])
+
+def flatten_errors(scope: Scope) -> Dict[str, List[str]]:
+    """Returns a (path -> errors) mapping of the leaf nodes
+    of the detailed error output"""
+    def iter_errors(d: dict) -> Iterator[Tuple[str, str]]:
+        if 'error' in d:
+            yield prettify_path(d['instanceLocation']), d['error']
+        elif 'errors' in d:
+            for error in d['errors']:
+                yield from iter_errors(error)
+
+    errors = defaultdict(list)
+    for path, message in iter_errors(scope.output('detailed')):
+        errors[path].append(message)
+
+    return {
+        key: value[0] if len(value) == 1 else value
+        for key, value in errors.items()
+    }
+
+def raise_if_invalid(scope: Scope):
+    __tracebackhide__ = True
+    if not scope.valid:
+        raise RuntimeError(flatten_errors(scope))
+
+def result_of(path: Path) -> Scope:
+    raw = json.loads(path.read_text())
+    instance = JSON(raw)
+    return SCHEMA.evaluate(instance)