Fix Psych disallowed class error by permitting Date in YAML.safe_load.

lib/rspec/openapi/schema_file.rb

@@ -3,6 +3,7 @@
 require 'fileutils'
 require 'yaml'
 require 'json'
+require 'date'
 
 # TODO: Support JSON
 class RSpec::OpenAPI::SchemaFile
@@ -24,7 +25,12 @@ def edit(&block)
   def read
     return {} unless File.exist?(@path)
 
-    RSpec::OpenAPI::KeyTransformer.symbolize(YAML.safe_load(File.read(@path))) # this can also parse JSON
+    RSpec::OpenAPI::KeyTransformer.symbolize(
+      YAML.safe_load(
+        File.read(@path),
+        permitted_classes: [Date],
+      ),
+    ) # this can also parse JSON
   end
 
   # @param [Hash] spec

spec/rspec/schema_file_spec.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'date'
+
+RSpec.describe RSpec::OpenAPI::SchemaFile do
+  describe '#read' do
+    let(:schema_content) do
+      <<~YAML
+        openapi: 3.0.0
+        info:
+          title: My API
+          version: 1.0.0
+        paths:
+          /:
+            get:
+              summary: A test endpoint
+              parameters:
+                - name: date
+                  in: query
+                  schema:
+                    type: string
+                    example: 2020-01-02 # Unquoted date
+      YAML
+    end
+
+    it 'deserializes unquoted dates as Date objects when Date is permitted' do
+      schema_file = RSpec::OpenAPI::SchemaFile.new('nonexistant/schema.yaml')
+
+      expect(File).to receive(:read).and_return(schema_content)
+      expect(File).to receive(:exist?).and_return(true)
+
+      data = nil
+      expect do
+        data = schema_file.send(:read)
+      end.not_to raise_error(Psych::DisallowedClass)
+      expect(data.dig(:paths, :/, :get, :parameters, 0, :schema, :example).to_s).to eq('2020-01-02')
+    end
+  end
+end