feat(proxy): add a flag to skip request validation

docs/getting-started/03-cli.md

@@ -139,6 +139,20 @@ curl -v -X POST http://localhost:4010/pet/
 
 The response body contains the found output violations.
 
+In some cases you may want to skip request validation. A common scenario would be where you want to check if your HTTP handlers validate the request appropriately.
+Prism will validate all requests by default, but you can skip this by setting the flag to `--validate-request` flag to `false`.
+
+```bash
+prism proxy examples/petstore.oas2.yaml https://petstore.swagger.io/v2 --errors --validate-request false
+```
+
+```bash
+curl -v -X POST http://localhost:4010/pet/ -d '{"name"": "Skip", "species": 100}'
+
+< HTTP/1.1 422 Unprocessable Entity
+{"statusCode": 400, "message": "Pet 'species' field should be a string, got integer", "code": "PET-ERROR-400"}
+```
+
 <!-- theme: info -->
 
 > Server definitions (OAS3) and Host + BasePath (OAS2) are ignored. You need to manually specify the upstream URL when invoking Prism.

packages/cli/src/commands/__tests__/commands.spec.ts

@@ -71,3 +71,11 @@ describe.each<{ 0: string; 1: string; 2: unknown }>([
     expect(createMultiProcessPrism).toHaveBeenLastCalledWith(expect.objectContaining({ errors: true }));
   });
 });
+
+test(`starts proxy server with default validate-request option to be overriden`, () => {
+  parser.parse(`proxy /path/to -m -h 0.0.0.0 ${new URL('https://github.com/')} --validate-request=false`);
+
+  expect(createMultiProcessPrism).toHaveBeenLastCalledWith(
+    expect.objectContaining({ validateRequest: false, host: '0.0.0.0' })
+  );
+});

packages/cli/src/commands/proxy.ts

@@ -1,8 +1,9 @@
 import { pick } from 'lodash';
-import { CommandModule } from 'yargs';
+import { CommandModule, parsed } from 'yargs';
 import { createMultiProcessPrism, CreateProxyServerOptions, createSingleProcessPrism } from '../util/createServer';
 import sharedOptions from './sharedOptions';
 import { runPrismAndSetupWatcher } from '../util/runner';
+import { boolean } from 'fp-ts';
 
 const proxyCommand: CommandModule = {
   describe: 'Start a proxy server with the given document file',
@@ -24,18 +25,27 @@ const proxyCommand: CommandModule = {
           throw new Error(`Invalid upstream URL provided: ${value}`);
         }
       })
-      .options(sharedOptions),
+      .options({
+        ...sharedOptions,
+        'validate-request': {
+          description: 'Validate incoming HTTP requests.',
+          boolean: true,
+          default: true,
+        },
+      }),
   handler: parsedArgs => {
+    parsedArgs.validateRequest = parsedArgs['validate-request'];
     const p: CreateProxyServerOptions = pick(
-      (parsedArgs as unknown) as CreateProxyServerOptions,
+      parsedArgs as unknown as CreateProxyServerOptions,
       'dynamic',
       'cors',
       'host',
       'port',
       'document',
       'multiprocess',
       'upstream',
-      'errors'
+      'errors',
+      'validateRequest'
     );
 
     const createPrism = p.multiprocess ? createMultiProcessPrism : createSingleProcessPrism;

packages/cli/src/util/createServer.ts

@@ -73,8 +73,9 @@ async function createPrismServerWithLogger(options: CreateBaseServerOptions, log
     throw new Error('No operations found in the current file.');
   }
 
+  const validateRequest = isProxyServerOptions(options) ? options.validateRequest : true;
   const shared: Omit<IHttpConfig, 'mock'> = {
-    validateRequest: true,
+    validateRequest,
     validateResponse: true,
     checkSecurity: true,
     errors: false,
@@ -141,6 +142,7 @@ type CreateBaseServerOptions = {
 export interface CreateProxyServerOptions extends CreateBaseServerOptions {
   dynamic: false;
   upstream: URL;
+  validateRequest: boolean;
 }
 
 export type CreateMockServerOptions = CreateBaseServerOptions;