Include property value in the error message

When building a list of errors for `ValidationError.message`, include
the values of invalid properties too.

In order to keep the message reasonably short, the values are truncated
at approx 32 characters.

lib/validations.js

@@ -26,7 +26,7 @@ function Validatable() {
 }
 
 /**
- * Validate presence of one or more specified properties. 
+ * Validate presence of one or more specified properties.
  * Requires a model to include a property to be considered valid; fails when validated field is blank.
  *
  * For example, validate presence of title
@@ -49,7 +49,7 @@ function Validatable() {
 Validatable.validatesPresenceOf = getConfigurator('presence');
 
 /**
- * Validate absence of one or more specified properties. 
+ * Validate absence of one or more specified properties.
  * A model should not include a property to be considered valid; fails when validated field not blank.
  *
  * For example, validate absence of reserved
@@ -85,7 +85,7 @@ Validatable.validatesAbsenceOf = getConfigurator('absence');
  * User.validatesLengthOf('state', {is: 2, message: {is: 'is not valid state name'}});
  * ```
  * @param {String} propertyName  Property name to validate.
- * @options {Object} Options 
+ * @options {Object} Options
  * @property {Number} is Value that property must equal to validate.
  * @property {Number} min Value that property must be less than to be valid.
  * @property {Number} max Value that property must be less than to be valid.
@@ -103,7 +103,7 @@ Validatable.validatesLengthOf = getConfigurator('length');
  * ```
  *
  * @param {String} propertyName  Property name to validate.
- * @options {Object} Options 
+ * @options {Object} Options
  * @property {Boolean} int If true, then property must be an integer to be valid.
  * @property {Object} message Optional object with string properties for 'int' for integer validation.  Default error messages:
  * - number: is not a number
@@ -123,7 +123,7 @@ Validatable.validatesNumericalityOf = getConfigurator('numericality');
  * ```
  *
  * @param {String} propertyName  Property name to validate.
- * @options {Object} Options 
+ * @options {Object} Options
  * @property {Array} in Array Property must match one of the values in the array to be valid.
  * @property {String} message Optional error message if property is not valid.   Default error message: "is not included in the list".
  */
@@ -135,7 +135,7 @@ Validatable.validatesInclusionOf = getConfigurator('inclusion');
  * Example: `Company.validatesExclusionOf('domain', {in: ['www', 'admin']});`
  *
  * @param {String} propertyName  Property name to validate.
- * @options {Object} Options 
+ * @options {Object} Options
  * @property {Array} in Array Property must match one of the values in the array to be valid.
  * @property {String} message Optional error message if property is not valid.  Default error message: "is reserved".
  */
@@ -146,9 +146,9 @@ Validatable.validatesExclusionOf = getConfigurator('exclusion');
  *
  * Require a model to include a property that matches the given format.  Example:
  * `User.validatesFormat('name', {with: /\w+/});`
- * 
+ *
  * @param {String} propertyName  Property name to validate.
- * @options {Object} Options 
+ * @options {Object} Options
  * @property {RegExp} with Regular expression to validate format.
  * @property {String} message Optional error message if property is not valid.  Default error message: " is invalid".
  */
@@ -223,7 +223,7 @@ Validatable.validateAsync = getConfigurator('custom', {async: true});
  * ```
 
  * @param {String} propertyName  Property name to validate.
- * @options {Object} Options 
+ * @options {Object} Options
  * @property {RegExp} with Regular expression to validate format.
  * @property {Array.<String>} scopedTo List of properties defining the scope.
  * @property {String} message Optional error message if property is not valid.  Default error message: "is not unique".
@@ -437,7 +437,7 @@ Validatable.prototype.isValid = function (callback, data) {
       asyncFail = false;
 
     var attrs = Object.keys(validations || {});
-    
+
     attrs.forEach(function(attr) {
       var attrValidations = validations[attr] || [];
       attrValidations.forEach(function(v) {
@@ -454,7 +454,7 @@ Validatable.prototype.isValid = function (callback, data) {
         }
       });
     });
-    
+
     if (!async) {
       validationsDone.call(inst, function () {
         if (valid) cleanErrors(inst);
@@ -498,12 +498,12 @@ function cleanErrors(inst) {
 
 function validationFailed(inst, attr, conf, cb) {
   var opts = conf.options || {};
-  
+
   if (typeof attr !== 'string') return false;
 
   // here we should check skip validation conditions (if, unless)
   // that can be specified in conf
-  if (skipValidation(inst, conf, 'if') 
+  if (skipValidation(inst, conf, 'if')
     || skipValidation(inst, conf, 'unless')) {
     if (cb) cb(false);
     return false;
@@ -715,11 +715,11 @@ function ErrorCodes(messages) {
  *   for (var key in changes) {
  *     model[key] = changes[key];
  *   }
- * 
+ *
  *   if (model.isValid()) {
  *     return callback(null, { success: true });
  *   }
- * 
+ *
  *   // This line shows how to create a ValidationError
  *   err = new ValidationError(model);
  *   callback(err);
@@ -735,7 +735,7 @@ function ValidationError(obj) {
   this.message = util.format(
     'The %s instance is not valid. Details: %s.',
       context ? '`' + context + '`' : 'model',
-      formatErrors(obj.errors) || '(unknown)'
+      formatErrors(obj.errors, obj.toJSON()) || '(unknown)'
   );
 
   this.statusCode = 422;
@@ -761,7 +761,9 @@ util.inherits(ValidationError, Error);
 
 var errorHasStackProperty = !!(new Error).stack;
 
-function formatErrors(errors) {
+ValidationError.maxPropertyStringLength = 32;
+
+function formatErrors(errors, propertyValues) {
   var DELIM = '; ';
   errors = errors || {};
   return Object.getOwnPropertyNames(errors)
@@ -770,9 +772,52 @@ function formatErrors(errors) {
     })
     .map(function(propertyName) {
       var messages = errors[propertyName];
+      var propertyValue = propertyValues[propertyName];
       return messages.map(function(msg) {
-        return '`' + propertyName + '` ' + msg;
+        return formatPropertyError(propertyName, propertyValue, msg);
       }).join(DELIM);
     })
     .join(DELIM);
 }
+
+function formatPropertyError(propertyName, propertyValue, errorMessage) {
+  var formattedValue;
+  var valueType = typeof propertyValue;
+  if (valueType === 'string') {
+    formattedValue = JSON.stringify(truncatePropertyString(propertyValue));
+  } else if (propertyValue instanceof Date) {
+    formattedValue = propertyValue.toISOString();
+  } else if (valueType === 'object') {
+    // objects and arrays
+    formattedValue = util.inspect(propertyValue, {
+      showHidden: false,
+      color: false,
+      // show top-level object properties only
+      depth: Array.isArray(propertyValue) ? 1 : 0
+    });
+    formattedValue = truncatePropertyString(formattedValue);
+  } else {
+    formattedValue = truncatePropertyString('' + propertyValue);
+  }
+  return '`' + propertyName + '` ' + errorMessage +
+    ' (value: ' + formattedValue + ')';
+}
+
+function truncatePropertyString(value) {
+  var len = ValidationError.maxPropertyStringLength;
+  if (value.length <= len) return value;
+
+  // preserve few last characters like `}` or `]`, but no more than 3
+  // this way the last `} ]` in the array of objects is included in the message
+  var tail;
+  var m = value.match(/([ \t})\]]+)$/);
+  if (m) {
+    tail = m[1].slice(-3);
+    len -= tail.length;
+  } else {
+    tail = value.slice(-3);
+    len -= 3;
+  }
+
+  return value.slice(0, len-4) + '...' + tail;
+}

test/manipulation.test.js

@@ -66,8 +66,8 @@ describe('manipulation', function () {
     it('should not allow user-defined value for the id of object - create', function (done) {
       Person.create({id: 123456}, function (err, p) {
         err.should.be.instanceof(ValidationError);
-        err.message.should.equal('The `Person` instance is not valid. Details: `id` can\'t be set.');
         err.statusCode.should.equal(422);
+        err.details.messages.id.should.eql(['can\'t be set']);
         p.should.be.instanceof(Person);
         p.id.should.equal(123456);
         p.isNewRecord().should.be.true;
@@ -80,8 +80,8 @@ describe('manipulation', function () {
       p.isNewRecord().should.be.true;
       p.save(function(err, inst) {
         err.should.be.instanceof(ValidationError);
-        err.message.should.equal('The `Person` instance is not valid. Details: `id` can\'t be set.');
         err.statusCode.should.equal(422);
+        err.details.messages.id.should.eql(['can\'t be set']);
         inst.id.should.equal(123456);
         inst.isNewRecord().should.be.true;
         done();

test/relations.test.js

@@ -2111,9 +2111,7 @@ describe('relations', function () {
       p.passportItem.create({}, function(err, passport) {
         should.exist(err);
         err.name.should.equal('ValidationError');
-        var msg = 'The `Passport` instance is not valid.';
+        err.details.messages.name.should.eql(['can\'t be blank']);
-        msg += ' Details: `name` can\'t be blank.';
-        err.message.should.equal(msg);
         done();
       });
     });
@@ -2125,9 +2123,8 @@ describe('relations', function () {
         p.save(function(err) {
           should.exist(err);
           err.name.should.equal('ValidationError');
-          var msg = 'The `Person` instance is not valid.';
+          err.details.messages.passportItem
-          msg += ' Details: `passportItem` is invalid: `name` can\'t be blank.';
+            .should.eql(['is invalid: `name` can\'t be blank']);
-          err.message.should.equal(msg);
           done();
         });
       });
@@ -2568,9 +2565,9 @@ describe('relations', function () {
       addresses.push({ id: 'work', street: '' });
       Person.create({ name: 'Wilma', addresses: addresses }, function(err, p) {
         err.name.should.equal('ValidationError');
-        var expected = 'The `Person` instance is not valid. ';
+        err.details.messages.addresses.should.eql([
-        expected += 'Details: `addresses` contains invalid item: `work` (`street` can\'t be blank).';
+          'contains invalid item: `work` (`street` can\'t be blank)'
-        err.message.should.equal(expected);
+        ]);
         done();
       });
     });
@@ -2769,7 +2766,7 @@ describe('relations', function () {
           err.name.should.equal('ValidationError');
           err.details.codes.street.should.eql(['presence']);
           var expected = 'The `Address` instance is not valid. ';
-          expected += 'Details: `street` can\'t be blank.';
+          expected += 'Details: `street` can\'t be blank (value: undefined).';
           err.message.should.equal(expected);
           done();
         });
@@ -3225,9 +3222,6 @@ describe('relations', function () {
           should.exist(err);
           err.name.should.equal('ValidationError');
           err.details.codes.jobs.should.eql(['uniqueness']);
-          var expected = 'The `Category` instance is not valid. ';
-          expected += 'Details: `jobs` contains duplicate `Job` instance.';
-          err.message.should.equal(expected);
           done();
         });
       });

test/validations.test.js

@@ -211,6 +211,16 @@ describe('validations', function () {
         });
       });
 
+      it('should include property value in err.message', function(done) {
+        delete User.validations;
+        User.validatesPresenceOf('name');
+        User.create(function (e, u) {
+          should.exist(e);
+          e.message.should.match(/`name` can't be blank \(value: undefined\)/);
+          done();
+        });
+      });
+
       it('should include model name in err.message', function(done) {
         delete User.validations;
         User.validatesPresenceOf('name');
@@ -432,4 +442,65 @@ describe('validations', function () {
       })).should.be.false;
     });
   });
+
+  describe('invalid value formatting', function() {
+    var origMaxLen;
+    beforeEach(function saveAndSetMaxLen() {
+      origMaxLen = ValidationError.maxPropertyStringLength;
+    });
+
+    afterEach(function restoreMaxLen() {
+      ValidationError.maxPropertyStringLength = origMaxLen;
+    });
+
+    it('should truncate long strings', function() {
+      ValidationError.maxPropertyStringLength = 9;
+      var err = givenValidationError('prop', '1234567890abc', 'is invalid');
+      getErrorDetails(err)
+        .should.equal('`prop` is invalid (value: "12...abc").');
+    });
+
+    it('should truncate long objects', function() {
+      ValidationError.maxPropertyStringLength = 12;
+      var err = givenValidationError('prop', { foo: 'bar' }, 'is invalid');
+      getErrorDetails(err)
+        .should.equal('`prop` is invalid (value: { foo:... }).');
+    });
+
+    it('should truncate long arrays', function() {
+      ValidationError.maxPropertyStringLength = 12;
+      var err = givenValidationError('prop', [{ a: 1, b: 2}], 'is invalid');
+      getErrorDetails(err)
+        .should.equal('`prop` is invalid (value: [ { a...} ]).');
+    });
+
+    it('should print only top-level object properties', function() {
+      var err = givenValidationError('prop', { a: { b: 'c' }}, 'is invalid');
+      getErrorDetails(err)
+        .should.equal('`prop` is invalid (value: { a: [Object] }).');
+    });
+
+    it('should print only top-level props of objects in array', function() {
+      var err = givenValidationError('prop', [{ a: { b: 'c' }}], 'is invalid');
+      getErrorDetails(err)
+        .should.equal('`prop` is invalid (value: [ { a: [Object] } ]).');
+    });
+
+    function givenValidationError(propertyName, propertyValue, errorMessage) {
+      var jsonVal = {};
+      jsonVal[propertyName] = propertyValue;
+      var errorVal = {};
+      errorVal[propertyName] = [errorMessage];
+
+      var obj = {
+        errors: errorVal,
+        toJSON: function() { return jsonVal; }
+      };
+      return new ValidationError(obj);
+    }
+
+    function getErrorDetails(err) {
+      return err.message.replace(/^.*Details: /, '');
+    }
+  });
 });