top level discriminator support (oneOf, anyOf) for request bodies (#461)

* chore: update change log

* feat: add top level discriminator support #458

* validate one of

* continue if no discriminator option available found

CHANGE_HISTORY.md

@@ -1,3 +1,11 @@
+## 4.6.0 (2020-11-15)
+
+* chore: increment minor version ([af26e9c](https://github.com/cdimascio/express-openapi-validator/commit/af26e9c))
+* Allow ignorePaths to take function or regexp (#459) ([9b855d1](https://github.com/cdimascio/express-openapi-validator/commit/9b855d1)), closes [#459](https://github.com/cdimascio/express-openapi-validator/issues/459)
+* test: return 204 instead of 200 ([6a88a9c](https://github.com/cdimascio/express-openapi-validator/commit/6a88a9c))
+
+
+
 ## 4.5.0 (2020-11-09)
 
 * chore: increment minor version ([80de114](https://github.com/cdimascio/express-openapi-validator/commit/80de114))

src/middlewares/openapi.request.validator.ts

@@ -147,16 +147,26 @@ export class RequestValidator {
         cookies,
         body: req.body,
       };
+      const schemaBody = <any>validator?.schemaBody;
+      const discriminator = schemaBody?.properties?.body?._discriminator;
+      const discriminatorValdiator = this.discriminatorValidator(
+        req,
+        discriminator,
+      );
+
+      const validatorBody = discriminatorValdiator ?? validator.validatorBody;
       const valid = validator.validatorGeneral(data);
-      const validBody = validator.validatorBody(data);
+      const validBody = validatorBody(
+        discriminatorValdiator ? data.body : data,
+      );
 
       if (valid && validBody) {
         next();
       } else {
         const errors = augmentAjvErrors(
           []
             .concat(validator.validatorGeneral.errors ?? [])
-            .concat(validator.validatorBody.errors ?? []),
+            .concat(validatorBody.errors ?? []),
         );
         const err = ajvErrorsToValidatorError(400, errors);
         const message = this.ajv.errorsText(errors, { dataVar: 'request' });
@@ -170,6 +180,23 @@ export class RequestValidator {
     };
   }
 
+  private discriminatorValidator(req, discriminator) {
+    if (discriminator) {
+      const { options, property, validators } = discriminator;
+      const discriminatorValue = req.body[property]; // TODO may not alwasy be in this position
+      if (options.find((o) => o.option === discriminatorValue)) {
+        return validators[discriminatorValue];
+      } else {
+        throw new BadRequest({
+          path: req.path,
+          message: `'${property}' should be equal to one of the allowed values: ${options
+            .map((o) => o.option)
+            .join(', ')}.`,
+        });
+      }
+    }
+    return null;
+  }
   private processQueryParam(query: object, schema, whiteList: string[] = []) {
     const entries = Object.entries(schema.properties ?? {});
     let keys = [];

src/middlewares/parsers/request.schema.preprocessor.ts

@@ -58,6 +58,7 @@ export class RequestSchemaPreprocessor {
     const contentEntries = Object.entries(requestBody.content);
     for (const [_, mediaTypeObject] of contentEntries) {
       this.cleanseContentSchema(mediaTypeObject);
+      this.handleDiscriminator(mediaTypeObject);
     }
   }
 
@@ -104,6 +105,77 @@ export class RequestSchemaPreprocessor {
     return content.schema;
   }
 
+  private handleDiscriminator(content: OpenAPIV3.MediaTypeObject) {
+    const schemaObj = content.schema.hasOwnProperty('$ref')
+      ? <SchemaObject>this.ajv.getSchema(content.schema['$ref'])?.schema
+      : <SchemaObject>content.schema;
+
+    if (schemaObj.discriminator) {
+      this.discriminatorTraverse(null, schemaObj, {});
+    }
+  }
+
+  private discriminatorTraverse(parent: Schema, schema: Schema, o: any = {}) {
+    const schemaObj = schema.hasOwnProperty('$ref')
+      ? <SchemaObject>this.ajv.getSchema(schema['$ref'])?.schema
+      : <SchemaObject>schema;
+
+    const xOf = schemaObj.oneOf ? 'oneOf' : 'anyOf';
+    if (schemaObj?.discriminator?.propertyName && !o.discriminator) {
+      // TODO discriminator can be used for anyOf too!
+      const options = schemaObj[xOf].map((refObject) => {
+        const option = this.findKey(
+          schemaObj.discriminator.mapping,
+          (value) => value === refObject['$ref'],
+        );
+        const ref = this.getKeyFromRef(refObject['$ref']);
+        return { option: option || ref, ref };
+      });
+      o.options = options;
+      o.discriminator = schemaObj.discriminator?.propertyName;
+    }
+    o.properties = { ...(o.properties ?? {}), ...(schemaObj.properties ?? {}) };
+    o.required = Array.from(
+      new Set((o.required ?? []).concat(schemaObj.required ?? [])),
+    );
+
+    if (schemaObj[xOf]) {
+      schemaObj[xOf].forEach((s) =>
+        this.discriminatorTraverse(schemaObj, s, o),
+      );
+    } else if (schemaObj) {
+      const ancestor: any = parent;
+      const option =
+        this.findKey(
+          ancestor.discriminator?.mapping,
+          (value) => value === schema['$ref'],
+        ) || this.getKeyFromRef(schema['$ref']);
+
+      if (option) {
+        const newSchema = JSON.parse(JSON.stringify(schemaObj));
+        newSchema.properties = {
+          ...(o.properties ?? {}),
+          ...(newSchema.properties ?? {}),
+        };
+        newSchema.required = o.required;
+        if (newSchema.required.length === 0) {
+          delete newSchema.required;
+        }
+        ancestor._discriminator ??= {
+          validators: {},
+          options: o.options,
+          property: o.discriminator,
+        };
+        ancestor._discriminator.validators[option] = this.ajv.compile(
+          newSchema,
+        );
+      }
+      //reset data
+      o.properties = {};
+      delete o.required;
+    }
+  }
+
   private traverse(schema: Schema, f: (p, s) => void) {
     const schemaObj = schema.hasOwnProperty('$ref')
       ? <SchemaObject>this.ajv.getSchema(schema['$ref'])?.schema
@@ -121,4 +193,19 @@ export class RequestSchemaPreprocessor {
       });
     }
   }
+
+  private findKey(object, searchFunc) {
+    if (!object) {
+      return;
+    }
+    const keys = Object.keys(object);
+    for (let i = 0; i < keys.length; i++) {
+      if (searchFunc(object[keys[i]])) {
+        return keys[i];
+      }
+    }
+  }
+  getKeyFromRef(ref) {
+    return ref.split('/components/schemas/')[1];
+  }
 }

test/one.of.2.spec.ts

@@ -0,0 +1,163 @@
+import * as path from 'path';
+import { expect } from 'chai';
+import * as request from 'supertest';
+import { createApp } from './common/app';
+import * as packageJson from '../package.json';
+
+describe('one.of.2.spec', () => {
+  let app = null;
+
+  before(async () => {
+    const apiSpec = path.join('test', 'resources', 'one.of.2.yaml');
+    app = await createApp(
+      { apiSpec },
+      3005,
+      (app) => {
+        app.post(`${app.basePath}/discriminator_implied`, (req, res) =>
+          res.json(req.body),
+        );
+        app.post(`${app.basePath}/pets`, (req, res) => {
+          res.json(req.body);
+        });
+        app.post(`${app.basePath}/pets_all`, (req, res) => {
+          res.json(req.body);
+        });
+        app.use((err, req, res, next) => {
+          console.error(err);
+          res.status(err.status ?? 500).json({
+            message: err.message,
+            code: err.status ?? 500,
+          });
+        });
+      },
+      false,
+    );
+  });
+
+  after(() => {
+    app.server.close();
+  });
+
+  describe('/discriminator_implied', () => {
+    it('should return 200 for dog', async () =>
+      request(app)
+        .post(`${app.basePath}/discriminator_implied`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'DogObject',
+          bark: true,
+          breed: 'Dingo',
+        })
+        .expect(200));
+
+    it('should return 400 for dog with cat props', async () =>
+      request(app)
+        .post(`${app.basePath}/discriminator_implied`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'DogObject',
+          hunts: true,
+          age: 3,
+        })
+        .expect(400)
+        .then((r) => {
+          expect(r.body.message).to.include("required property 'bark'");
+        }));
+
+    it('should return 400 a bad discriminator', async () =>
+      request(app)
+        .post(`${app.basePath}/discriminator_implied`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'dog',
+          bark: true,
+          breed: 'Dingo',
+        })
+        .expect(400)
+        .then((r) => {
+          expect(r.body.message).to.include(
+            'one of the allowed values: CatObject, DogObject',
+          );
+        }));
+  });
+
+  describe('/pets', () => {
+    it('should return 400 a bad discriminator', async () =>
+      request(app)
+        .post(`${app.basePath}/pets`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'DogObject',
+          bark: true,
+          breed: 'Dingo',
+        })
+        .expect(400)
+        .then((r) => {
+          const e = r.body;
+          expect(e.message).to.include('one of the allowed values: cat, dog');
+        }));
+
+    it('should return 200 for dog', async () =>
+      request(app)
+        .post(`${app.basePath}/pets`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'dog',
+          bark: true,
+          breed: 'Dingo',
+        })
+        .expect(200));
+
+    it('should return 200 for cat', async () =>
+      request(app)
+        .post(`${app.basePath}/pets`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'cat',
+          hunts: true,
+          age: 3,
+        })
+        .expect(200));
+  });
+
+  describe('/pets_all', () => {
+    it('should return 400 a bad discriminator', async () =>
+      request(app)
+        .post(`${app.basePath}/pets_all`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'dog',
+          bark: true,
+          breed: 'Dingo',
+        })
+        .expect(400)
+        .then((r) => {
+          const e = r.body;
+          expect(e.message).to.include(
+            'to one of the allowed values: Cat, Dog',
+          );
+        }));
+
+    it('should return 200 for Dog', async () =>
+      request(app)
+        .post(`${app.basePath}/pets_all`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'Dog',
+          bark: true,
+          breed: 'Dingo',
+        })
+        .expect(200));
+
+    it('should return 200 for Cat', async () =>
+      request(app)
+        .post(`${app.basePath}/pets_all`)
+        .set('content-type', 'application/json')
+        .send({
+          pet_type: 'Cat',
+          hunts: true,
+          age: 3,
+        })
+        .expect(200));
+  });
+});

test/oneof.readonly.spec.ts

@@ -46,20 +46,31 @@ describe('one.of readonly', () => {
       .expect(400)
       .then((r) => {
         const error = r.body;
+        console.log(error);
         expect(error.message).to.include('to one of the allowed values: C, D');
       }));
 
+  it('post type oneOf (without readonly id) should pass', async () =>
+    request(app)
+      .post(`${app.basePath}/one_of`)
+      .send({ type: 'C' })
+      .set('Content-Type', 'application/json')
+      .expect(200));
+
   it('post type anyof without providing the single required readonly property should pass', async () =>
     request(app)
       .post(`${app.basePath}/one_of`)
       .send({ type: 'C' }) // do not provide id
       .set('Content-Type', 'application/json')
       .expect(200));
 
-  it('post type oneOf (without readonly id) should pass', async () =>
+  it('should fail if posting anyof with bad discriminator', async () =>
     request(app)
       .post(`${app.basePath}/one_of`)
-      .send({ type: 'C' })
+      .send({ type: 'A' }) // do not provide id
       .set('Content-Type', 'application/json')
-      .expect(200));
+      .expect(400)
+      .then((r) => {
+        expect(r.body.message).includes('to one of the allowed values: C, D');
+      }));
 });

test/oneof.readonly.yaml

@@ -53,8 +53,8 @@ paths:
                 discriminator:
                   propertyName: type
                   mapping:
-                    A: '#/components/schemas/subC'
-                    B: '#/components/schemas/subD'
+                    C: '#/components/schemas/subC'
+                    D: '#/components/schemas/subD'
       responses:
           200:
             description: successful operation