fixes stream validation

middleware/swagger-validator.js

@@ -31,6 +31,20 @@ var debug = require('debug')('swagger-tools:middleware:validator');
 var mHelpers = require('./helpers');
 var validators = require('../lib/validators');
 
+var checkIsFile = function (schema, version) {
+  var isFile = false;
+  if (version === '1.2') {
+    var type = (schema.items ? schema.items.type || schema.items.$ref : schema.type);
+    isFile = type === 'file';
+  }
+  else {
+    if (!_.isUndefined(schema.schema)) {
+      isFile = schema.schema.type === 'file';
+    }
+  }
+  return isFile;
+};
+
 var sendData = function (swaggerVersion, res, data, encoding, skipped) {
   // 'res.end' requires a Buffer or String so if it's not one, create a String
   if (!(data instanceof Buffer) && !_.isString(data)) {
@@ -203,6 +217,11 @@ var wrapEnd = function (req, res, next) {
         val = data;
       }
     }
+    else if(writtenData.length === 0) {
+      // Some code expects val to be undefined and not an empty string
+      // when no data is passed to 'end' or written with 'write'.
+      val = undefined;
+    }
     else if(writtenData.length !== 0) {
       val = Buffer.concat(writtenData);
     }
@@ -216,9 +235,6 @@ var wrapEnd = function (req, res, next) {
     debug('  Response validation:');
 
     // If the data is a buffer, convert it to a string so we can parse it prior to validation
-    if (val instanceof Buffer) {
-      val = val.toString(encoding);
-    }
 
     // Express removes the Content-Type header from 204/304 responses which makes response validation impossible
     if (_.isUndefined(res.getHeader('content-type')) && [204, 304].indexOf(res.statusCode) > -1) {
@@ -281,6 +297,11 @@ var wrapEnd = function (req, res, next) {
       if (_.isUndefined(schema)) {
         sendData(swaggerVersion, res, val, encoding, true);
       } else {
+        // If the data is a buffer, convert it to a string so we can parse it prior to validation
+        var isFile = checkIsFile(schema, req.swagger.apiDeclaration ? '1.2' : '2.0');
+        if (val instanceof Buffer && !isFile) {
+          val = val.toString(encoding);
+        }
         validateValue(req, schema, vPath, val, 'body', function (err) {
           if (err) {
             throw err;

test/2.0/test-middleware-swagger-validator.js

@@ -37,6 +37,8 @@ var async = require('async');
 var helpers = require('../helpers');
 var request = require('supertest');
 var stream = require('stream');
+var fs = require('fs');
+var crypto = require('crypto');
 
 var petStoreJson = _.cloneDeep(require('../../samples/2.0/petstore.json'));
 
@@ -1135,7 +1137,45 @@ describe('Swagger Validator Middleware v2.0', function () {
       });
     });
 
+    it('should not return an error with a null schema on an empty response', function (done) {
+      var cPetStoreJson = _.cloneDeep(petStoreJson);
 
+      cPetStoreJson.paths['/redirect'] = {
+        'get': {
+          'x-swagger-router-controller': 'Test',
+          'operationId': 'redirectTest',
+          'responses': {
+            '302': {
+              'description': 'Redirect'
+            }
+          }
+        }
+      };
+
+      helpers.createServer([cPetStoreJson], {
+        swaggerRouterOptions: {
+          controllers: {
+            'Test_redirectTest': function (req, res) {
+              res.statusCode = 302;
+              res.end();
+            }
+          }
+        },
+        swaggerValidatorOptions: {
+          validateResponse: true
+        }
+      }, function (app) {
+        request(app)
+          .get('/api/redirect')
+          .expect(302)
+          .end(function (err, res) {
+            if (err) {
+              throw err + '\n' + res.error.text;
+            }
+            done();
+          });
+      });
+    });
 
     it('should validate a valid piped response', function (done) {
       var cPetStoreJson = _.cloneDeep(petStoreJson);
@@ -1575,6 +1615,55 @@ describe('Swagger Validator Middleware v2.0', function () {
       });
     });
 
+    it('should validate file and return it (issue #463)', function (done) {
+      var cPetStore = _.cloneDeep(petStoreJson);
+
+      cPetStore.paths['/image'] = {
+        get: {
+          summary: 'Get image',
+          description: 'Retrieves image.',
+          operationId: 'getImage',
+          produces: ['image/png'],
+          responses: {
+            '200': {
+              description: 'OK',
+              schema: {
+                type: 'file'
+              }
+            }
+          }
+        }
+      };
+
+      helpers.createServer([cPetStore], {
+        swaggerRouterOptions: {
+          controllers: {
+            getImage: function (req, res) {
+              res.setHeader('Content-type', 'image/png');
+              return fs.createReadStream('test/image.png').pipe(res);
+            }
+          }
+        },
+        swaggerValidatorOptions: {
+          validateResponse: true
+        }
+      }, function (app) {
+        try {
+          request(app)
+            .get('/api/image')
+            .end(function(err, res) {
+              assert.strictEqual(
+                crypto.createHash('sha256').update(fs.readFileSync('test/image.png')).digest('hex'), //expected
+                crypto.createHash('sha256').update(res.body).digest('hex') //actual
+              );
+              done(err);
+            });
+        } catch (err) {
+          done();
+        }
+      });
+    });
+
     it('should not throw an error for empty responses that validate void (new issue)', function (done) {
       var cPetStoreJson = _.cloneDeep(petStoreJson);