Handle additional OAS keywords (#141)

* log errors in strict mode

* add changeset

* fix typos

* change changeset message

* change title

* update comment

* remove unused line

* add line between functions

---------

Co-authored-by: nthapa <nthapa@atlassian.com>

Author: nabinked

.changeset/eighty-falcons-refuse.md

@@ -0,0 +1,5 @@
+---
+'oas3-chow-chow': patch
+---
+
+handle additional open api keywords

__test__/chow-keywords.spec.ts

@@ -0,0 +1,51 @@
+import { OpenAPIObject } from 'openapi3-ts';
+import ChowChow from '../src';
+const doc: (additionalKeywords: Record<string, any>) => OpenAPIObject = (
+  additionalKeywords = {}
+) => ({
+  openapi: '3.0.1',
+  info: {
+    title: 'service open api spec',
+    version: '1.0.1',
+  },
+  components: {
+    schemas: {
+      ResolveUnsupportedError: {
+        type: 'object',
+        properties: {
+          error: {},
+        },
+        ...additionalKeywords,
+      },
+    },
+  },
+  paths: {
+    '/resolve': {
+      post: {
+        operationId: 'resolve',
+        responses: {
+          '404': {
+            content: {
+              'application/json': {
+                schema: {
+                  $ref: '#/components/schemas/ResolveUnsupportedError',
+                },
+              },
+            },
+          },
+        },
+      },
+    },
+  },
+});
+
+describe('additional open api keywords', () => {
+  it.each([
+    { discriminator: '' },
+    { example: '' },
+    { externalDocs: '' },
+    { xml: '' },
+  ])('"%s" keyword should be allowed by default', async (additionalKeyword) => {
+    expect(await ChowChow.create(doc(additionalKeyword))).toBeDefined();
+  });
+});

__test__/chow-strict.spec.ts

@@ -0,0 +1,49 @@
+import { OpenAPIObject, PathItemObject } from 'openapi3-ts';
+import ChowChow from '../src';
+
+/**
+ * https://ajv.js.org/strict-mode.html
+ */
+describe('strict mode', () => {
+  it('show log warn and not throw by default', async () => {
+    const warnSpy = jest.spyOn(console, 'warn').mockImplementation();
+    const doc: OpenAPIObject = {
+      openapi: '3.0.1',
+      info: {
+        title: 'service open api spec',
+        version: '1.0.1',
+      },
+      components: {
+        schemas: {
+          ResolveUnsupportedError: {
+            type: 'array',
+            additionalItems: false,
+          },
+        },
+      },
+      paths: {
+        '/resolve': {
+          post: {
+            operationId: 'resolve',
+            responses: {
+              '404': {
+                content: {
+                  'application/json': {
+                    schema: {
+                      $ref: '#/components/schemas/ResolveUnsupportedError',
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    };
+    expect(await ChowChow.create(doc)).toBeDefined();
+    expect(warnSpy).toHaveBeenCalledWith(
+      'strict mode: "additionalItems" is ignored when "items" is not an array of schemas'
+    );
+    warnSpy.mockRestore();
+  });
+});

src/compiler/CompiledSchema.ts

@@ -8,7 +8,21 @@ export default class CompiledSchema {
   private validator: Ajv.ValidateFunction;
 
   constructor(schema: SchemaObject, opts?: Ajv.Options, context?: any) {
-    this.schemaObject = schema;
+    /**
+     * Remove unsupported additional OpenAPI keywords.
+     * https://swagger.io/docs/specification/data-models/keywords/ See "Additional Keywords"
+     * Does not include all keywords listed in that page/section because some of them are supported by ajv https://ajv.js.org/json-schema.html#openapi-support
+     * and some are explictly added within this class.
+     */
+    const {
+      discriminator,
+      example,
+      externalDocs,
+      xml,
+      ...schemaObject
+    } = schema;
+    this.schemaObject = schemaObject;
+
     const ajvInstance = ajv(opts);
     ajvInstance.removeKeyword('writeOnly');
     ajvInstance.removeKeyword('readOnly');
@@ -22,7 +36,7 @@ export default class CompiledSchema {
       validate: (schema: any) =>
         schema ? context.schemaContext === 'response' : true,
     });
-    this.validator = ajvInstance.compile(schema);
+    this.validator = ajvInstance.compile(schemaObject);
   }
 
   public validate(value: any) {

src/compiler/ajv.ts

@@ -1,7 +1,7 @@
 import Ajv, { Options } from 'ajv';
 import addFormats from 'ajv-formats';
 
-const options: Options = {};
+const options: Options = { strict: 'log' };
 
 export default function ajv(opts: Options = {}) {
   const ajv = new Ajv({