Setup spotlight project

.stoplight/custom-functions/oasDiscriminator.js

@@ -0,0 +1,38 @@
+function isObject(value) {
+  return value !== null && typeof value === 'object';
+}
+
+export const oasDiscriminator = (schema, _opts, { path }) => {
+  /**
+   * This function verifies:
+   *
+   * 1. The discriminator property name is defined at this schema.
+   * 2. The discriminator property is in the required property list.
+   */
+
+  if (!isObject(schema)) return;
+
+  if (typeof schema.discriminator !== 'string') return;
+
+  const discriminatorName = schema.discriminator;
+
+  const results = [];
+
+  if (!isObject(schema.properties) || !Object.keys(schema.properties).some(k => k === discriminatorName)) {
+    results.push({
+      message: `The discriminator property must be defined in this schema.`,
+      path: [...path, 'properties'],
+    });
+  }
+
+  if (!Array.isArray(schema.required) || !schema.required.some(n => n === discriminatorName)) {
+    results.push({
+      message: `The discriminator property must be in the required property list.`,
+      path: [...path, 'required'],
+    });
+  }
+
+  return results;
+};
+
+export default oasDiscriminator;