Merge pull request #110 from kytrinyx/derefence-child-without-ref

Dereference schema children for subschemas without a reference

lib/json_schema/reference_expander.rb

@@ -84,9 +84,25 @@ def build_schema_paths(uri, schema)
       end
     end
 
-    def dereference(ref_schema, ref_stack)
+    def dereference(ref_schema, ref_stack, parent_ref: nil)
       ref = ref_schema.reference
 
+      # Some schemas don't have a reference, but do
+      # have children. If that's the case, we need to
+      # dereference the subschemas.
+      if !ref
+        schema_children(ref_schema) do |subschema|
+          next unless subschema.reference
+
+          if !subschema.reference.uri && parent_ref
+            subschema.reference = JsonReference::Reference.new("#{parent_ref.uri}#{subschema.reference.pointer}")
+          end
+
+          dereference(subschema, ref_stack)
+        end
+        return true
+      end
+
       # detects a reference cycle
       if ref_stack.include?(ref)
         message = %{Reference loop detected: #{ref_stack.sort.join(", ")}.}
@@ -110,22 +126,33 @@ def dereference(ref_schema, ref_stack)
       # references.
       if ref.uri
         schema_children(new_schema) do |subschema|
-          next if subschema.expanded?
-          next unless subschema.reference
-
           # Don't bother if the subschema points to the same
           # schema as the reference schema.
           next if ref_schema == subschema
 
-          if !subschema.reference.uri
-            # the subschema's ref is local to the file that the
-            # subschema is in; however since there's no URI
-            # the 'resolve_pointer' method would try to look it up
-            # within @schema. So: manually reconstruct the reference to
-            # use the URI of the parent ref.
-            subschema.reference = JsonReference::Reference.new("#{ref.uri}#{subschema.reference.pointer}")
+          if subschema.reference
+            # If the subschema has a reference, then
+            # we don't need to recurse if the schema is
+            # already expanded.
+            next if subschema.expanded?
+
+            if !subschema.reference.uri
+              # the subschema's ref is local to the file that the
+              # subschema is in; however since there's no URI
+              # the 'resolve_pointer' method would try to look it up
+              # within @schema. So: manually reconstruct the reference to
+              # use the URI of the parent ref.
+              subschema.reference = JsonReference::Reference.new("#{ref.uri}#{subschema.reference.pointer}")
+            end
           end
-          dereference(subschema, ref_stack)
+
+          # If we're recursing into a schema via a global reference, then if
+          # the current subschema doesn't have a reference, we have no way of
+          # figuring out what schema we're in. The resolve_pointer method will
+          # default to looking it up in the initial schema. Instead, we're
+          # passing the parent ref here, so we can grab the URI
+          # later if needed.
+          dereference(subschema, ref_stack, parent_ref: ref)
         end
       end
 

test/json_schema/reference_expander_test.rb

@@ -320,6 +320,104 @@
     assert_equal 3, schema1.properties["foo"].properties["omg"].max_length
   end
 
+  it "it handles oneOf with nested references to an external schema" do
+    sample1 = {
+      "$schema" => "http://json-schema.org/draft-04/hyper-schema",
+      "type" => "object",
+      "properties" => {
+        "foo" => {
+          "$ref" => "http://json-schema.org/b.json#"
+        }
+      }
+    }
+    schema1 = JsonSchema::Parser.new.parse!(sample1)
+    schema1.uri = "http://json-schema.org/a.json"
+
+    sample2 = {
+      "$schema" => "http://json-schema.org/draft-04/hyper-schema",
+      "type" => "object",
+      "properties" => {
+        "bar" => {
+          "oneOf" => [
+            {"type" => "null"},
+            {"$ref" => "http://json-schema.org/c.json#"}
+          ]
+        }
+      },
+    }
+    schema2 = JsonSchema::Parser.new.parse!(sample2)
+    schema2.uri = "http://json-schema.org/b.json"
+
+    sample3 = {
+      "$schema" => "http://json-schema.org/draft-04/hyper-schema",
+      "type" => "object",
+      "properties" => {
+        "baz" => {
+          "type" => "string",
+          "maxLength" => 3
+        }
+      }
+    }
+    schema3 = JsonSchema::Parser.new.parse!(sample3)
+    schema3.uri = "http://json-schema.org/c.json"
+
+    # Initialize a store and add our schema to it.
+    store = JsonSchema::DocumentStore.new
+    store.add_schema(schema1)
+    store.add_schema(schema2)
+    store.add_schema(schema3)
+
+    expander = JsonSchema::ReferenceExpander.new
+    expander.expand(schema1, store: store)
+
+    assert_equal 3, schema1.properties["foo"].properties["bar"].one_of[1].properties["baz"].max_length
+  end
+
+  it "it handles oneOf with nested references to a local schema" do
+    sample1 = {
+      "$schema" => "http://json-schema.org/draft-04/hyper-schema",
+      "type" => "object",
+      "properties" => {
+        "foo" => {
+          "$ref" => "http://json-schema.org/b.json#"
+        }
+      }
+    }
+    schema1 = JsonSchema::Parser.new.parse!(sample1)
+    schema1.uri = "http://json-schema.org/a.json"
+
+    sample2 = {
+      "$schema" => "http://json-schema.org/draft-04/hyper-schema",
+      "type" => "object",
+      "definitions" => {
+        "baz" => {
+          "type" => "string",
+          "maxLength" => 3
+        }
+      },
+      "properties" => {
+        "bar" => {
+          "oneOf" => [
+            {"type" => "null"},
+            {"$ref" => "#/definitions/baz"}
+          ]
+        }
+      },
+    }
+    schema2 = JsonSchema::Parser.new.parse!(sample2)
+    schema2.uri = "http://json-schema.org/b.json"
+
+    # Initialize a store and add our schema to it.
+    store = JsonSchema::DocumentStore.new
+    store.add_schema(schema1)
+    store.add_schema(schema2)
+
+    expander = JsonSchema::ReferenceExpander.new
+    expander.expand(schema1, store: store)
+
+    assert_equal 3, schema1.properties["foo"].properties["bar"].one_of[1].max_length
+  end
+
   it "expands a schema with a reference to an external schema with a nested local property reference" do
     sample1 = {
       "$schema" => "http://json-schema.org/draft-04/hyper-schema",