fix(getEntities): Fixes issue with invalid limit.

Author: ryasmi

readme.md

@@ -27,6 +27,8 @@ export interface TodoEntity extends Entity {
 import factory from '@js-entity-repos/express/dist/factory';
 
 const todosFacade = factory<TodoEntity>({
+  // Optional property that determines the default pagination limit.
+  defaultPaginationLimit: 10,
   // Optional property that catches errors from handlers.
   errorCatcher: (handler) => (req, res) => {
     handler(req, res).catch((err) => {

src/FacadeConfig.ts

@@ -5,4 +5,5 @@ import ErrorCatcher from './utils/ErrorCatcher';
 export default interface FacadeConfig<E extends Entity> {
   readonly service: Facade<E>;
   readonly errorCatcher: ErrorCatcher;
+  readonly defaultPaginationLimit: number;
 }

src/FactoryConfig.ts

@@ -5,4 +5,5 @@ import ErrorCatcher from './utils/ErrorCatcher';
 export default interface FactoryConfig<E extends Entity> {
   readonly service: Facade<E>;
   readonly errorCatcher?: ErrorCatcher;
+  readonly defaultPaginationLimit?: number;
 }

src/factory.test.ts

@@ -43,7 +43,7 @@ facadeTest(axiosFactory<TestEntity>({
 }));
 
 describe('facade', () => {
-  it('should not throw JSON error', async () => {
+  it('should not throw errors when not using any query params', async () => {
     const response = await axiosClient.get('/');
     assert.equal(response.status, OK);
   });
@@ -54,4 +54,11 @@ describe('facade', () => {
       assert.equal(err.response.status, BAD_REQUEST);
     });
   });
+  it('should throw number error when using invalid limit', async () => {
+    await axiosClient.get('/?limit=invalid_number').then((response) => {
+      return { response };
+    }).catch((err) => {
+      assert.equal(err.response.status, BAD_REQUEST);
+    });
+  });
 });

src/factory.ts

@@ -15,6 +15,7 @@ import catchErrors from './utils/catchErrors';
 
 export default <E extends Entity>(factoryConfig: FactoryConfig<E>): Router => {
   const facadeConfig: FacadeConfig<E> = {
+    defaultPaginationLimit: 10,
     errorCatcher: catchErrors,
     ...factoryConfig,
   };

src/functions/getEntities.ts

@@ -4,15 +4,17 @@ import { OK } from 'http-status-codes';
 import FacadeConfig from '../FacadeConfig';
 import catchErrors from '../utils/catchErrors';
 import getJsonQueryParam from '../utils/getJsonQueryParam';
+import getNumberQueryParam from '../utils/getNumberQueryParam';
 
 export default <E extends Entity>(config: FacadeConfig<E>) => {
   return catchErrors(async (req: Request, res: Response) => {
+    const limit = getNumberQueryParam(req.query, 'limit', config.defaultPaginationLimit);
     const result = await config.service.getEntities({
       filter: getJsonQueryParam(req.query, 'filter'),
       pagination: {
         cursor: req.query.cursor,
         forward: req.query.forward === 'true',
-        limit: Number(req.query.limit),
+        limit,
       },
       sort: getJsonQueryParam(req.query, 'sort'),
     });

src/utils/JsonError.ts

@@ -0,0 +1,8 @@
+// tslint:disable:no-class
+import { BaseError } from 'make-error';
+
+export default class JsonError extends BaseError {
+  constructor(public data: any, public path: string[]) {
+    super();
+  }
+}

src/utils/JsonSyntaxError.ts

@@ -0,0 +1,8 @@
+// tslint:disable:no-class
+import { BaseError } from 'make-error';
+
+export default class NumberError extends BaseError {
+  constructor(public data: any, public path: string[]) {
+    super();
+  }
+}

src/utils/NumberError.ts

@@ -0,0 +1,3 @@
+export default interface Query {
+  readonly [k: string]: string | undefined;
+}

src/utils/Query.ts

@@ -2,7 +2,8 @@ import ConflictingEntityError from '@js-entity-repos/core/dist/errors/Conflictin
 import MissingEntityError from '@js-entity-repos/core/dist/errors/MissingEntityError';
 import { BAD_REQUEST, CONFLICT, INTERNAL_SERVER_ERROR, NOT_FOUND } from 'http-status-codes';
 import ErrorCatcher from './ErrorCatcher';
-import JsonSyntaxError from './JsonSyntaxError';
+import JsonError from './JsonError';
+import NumberError from './NumberError';
 
 const errorCatcher: ErrorCatcher = (handler) => {
   return (req, res) => {
@@ -13,7 +14,10 @@ const errorCatcher: ErrorCatcher = (handler) => {
       if (err instanceof MissingEntityError) {
         return res.status(NOT_FOUND).send();
       }
-      if (err instanceof JsonSyntaxError) {
+      if (err instanceof JsonError) {
+        return res.status(BAD_REQUEST).send();
+      }
+      if (err instanceof NumberError) {
         return res.status(BAD_REQUEST).send();
       }
       /* istanbul ignore next */

src/utils/catchErrors.ts

@@ -1,6 +1,7 @@
 import parseJson from './parseJson';
+import Query from './Query';
 
-export default (data: { readonly [k: string]: string | undefined }, paramName: string) => {
+export default (data: Query, paramName: string) => {
   const paramValue = data[paramName];
   return paramValue === undefined ? undefined : parseJson(paramValue, [paramName]);
 };

src/utils/getJsonQueryParam.ts

@@ -0,0 +1,14 @@
+import NumberError from './NumberError';
+import Query from './Query';
+
+export default <T>(query: Query, paramName: string, defaultValue: T) => {
+  const paramValue = query[paramName];
+  if (paramValue === undefined) {
+    return defaultValue;
+  }
+  const parsedParamValue = Number(paramValue);
+  if (isNaN(parsedParamValue)) {
+    throw new NumberError(paramValue, [paramName]);
+  }
+  return parsedParamValue;
+};

src/utils/getNumberQueryParam.ts

@@ -1,11 +1,11 @@
-import JsonSyntaxError from './JsonSyntaxError';
+import JsonError from './JsonError';
 
 export default (data: string, path: string[]) => {
   try {
     return JSON.parse(data);
   } catch (err) {
     if (err instanceof SyntaxError) {
-      throw new JsonSyntaxError(path);
+      throw new JsonError(data, path);
     }
     /* istanbul ignore next */
     throw err;