chore: ensmarten types for example prop

Author: maxholman

lib/schema.ts

@@ -1,12 +1,36 @@
 import { Construct } from 'constructs';
 import type { oas31 } from 'openapi3-ts';
 
-interface SchemaOptions<T extends oas31.SchemaObject> {
-  schema: T;
-}
+type InferExample<T> = T extends oas31.ReferenceObject
+  ? any
+  : T extends {
+        type: 'string';
+      }
+    ? string
+    : T extends {
+          type: 'number' | 'integer';
+        }
+      ? number
+      : T extends {
+            type: 'boolean';
+          }
+        ? boolean
+        : T extends oas31.SchemaObject & { type: 'object' }
+          ? {
+              [K in keyof T['properties']]: InferExample<T['properties'][K]>;
+            }
+          : T extends oas31.SchemaObject & { type: 'array' }
+            ? InferExample<T['items']>[]
+            : any;
+
+export type SchemaOptions<T extends oas31.SchemaObject> = {
+  schema: T & {
+    examples?: InferExample<T>[];
+  };
+};
 
 export class Schema<
-  T extends oas31.SchemaObject = oas31.SchemaObject,
+  const T extends oas31.SchemaObject = oas31.SchemaObject,
 > extends Construct {
   private options: SchemaOptions<T>;
 
@@ -40,6 +64,9 @@ export class Schema<
   }
 
   public synth() {
-    return this.options.schema;
+    return {
+      additionalProperties: false,
+      ...this.options.schema,
+    };
   }
 }