Update json schema ref to OAS 3 (#119)

Author: perdy

docs/json_schema.md

@@ -1,10 +1,10 @@
 TypeSystem can convert Schema or Field instances to/from JSON Schema.
 
 !!! note
-    TypeSystem only supports `$ref` pointers that use the standard "definitions"
+    TypeSystem only supports `$ref` pointers that use the standard "components/schemas"
     namespace to store referenced schemas.
 
-    All references should be of the style `{"$ref": "#/definitions/..."}`.
+    All references should be of the style `{"$ref": "#/components/schemas/..."}`.
 
     Using hyperlinked references, relative references, or references to parts
     of the document other than "definitions" is not supported.

tests/jsonschema/draft7/definitionsRef.json

@@ -4,10 +4,10 @@
         "schema": {
             "definitions": {
                 "a": {"type": "integer"},
-                "b": {"$ref": "#/definitions/a"},
-                "c": {"$ref": "#/definitions/b"}
+                "b": {"$ref": "#/components/schemas/a"},
+                "c": {"$ref": "#/components/schemas/b"}
             },
-            "$ref": "#/definitions/c"
+            "$ref": "#/components/schemas/c"
         },
         "tests": [
             {
@@ -32,7 +32,7 @@
             },
             "properties": {
                 "foo": {
-                    "$ref": "#/definitions/reffed",
+                    "$ref": "#/components/schemas/reffed",
                     "maxItems": 2
                 }
             }
@@ -58,7 +58,7 @@
     {
         "description": "$ref to boolean schema true",
         "schema": {
-            "$ref": "#/definitions/bool",
+            "$ref": "#/components/schemas/bool",
             "definitions": {
                 "bool": true
             }
@@ -74,7 +74,7 @@
     {
         "description": "$ref to boolean schema false",
         "schema": {
-            "$ref": "#/definitions/bool",
+            "$ref": "#/components/schemas/bool",
             "definitions": {
                 "bool": false
             }

tests/test_schemas.py

@@ -451,7 +451,7 @@ def test_nested_schema_to_json_schema():
         "properties": {
             "title": {"type": "string", "minLength": 1, "maxLength": 100},
             "release_date": {"type": "string", "minLength": 1, "format": "date"},
-            "artist": {"$ref": "#/definitions/Artist"},
+            "artist": {"$ref": "#/components/schemas/Artist"},
         },
         "required": ["title", "release_date", "artist"],
         "definitions": {
@@ -502,7 +502,7 @@ def test_definitions_to_json_schema():
                         "minLength": 1,
                         "format": "date",
                     },
-                    "artist": {"$ref": "#/definitions/Artist"},
+                    "artist": {"$ref": "#/components/schemas/Artist"},
                 },
                 "required": ["title", "release_date", "artist"],
             },

typesystem/json_schema.py

@@ -116,7 +116,7 @@ def from_json_schema(
     if definitions is None:
         definitions = Definitions()
         for key, value in data.get("definitions", {}).items():
-            ref = f"#/definitions/{key}"
+            ref = f"#/components/schemas/{key}"
             definitions[ref] = from_json_schema(value, definitions=definitions)
 
     if "$ref" in data:
@@ -421,7 +421,7 @@ def to_json_schema(
             definitions[key] = to_json_schema(value, _definitions=definitions)
 
     if isinstance(field, Reference):
-        data["$ref"] = f"#/definitions/{field.to}"
+        data["$ref"] = f"#/components/schemas/{field.to}"
         definitions[field.to] = to_json_schema(field.target, _definitions=definitions)
 
     elif isinstance(field, String):