fix: improve JSON Schema conversion for number.port() and number.sign()

- Add jsonSchema conversion for number.port() rule, producing
  type: integer with minimum: 0 and maximum: 65535
- Replace non-standard x-constraint for number.sign() with proper
  JSON Schema keywords: exclusiveMinimum: 0 for positive,
  exclusiveMaximum: 0 for negative

Author: mahmoodhamdi

lib/types/number.js

@@ -269,6 +269,13 @@ module.exports = Any.extend({
                 }
 
                 return helpers.error('number.port');
+            },
+            jsonSchema(rule, res) {
+
+                res.type = 'integer';
+                res.minimum = 0;
+                res.maximum = 65535;
+                return res;
             }
         },
 
@@ -318,7 +325,13 @@ module.exports = Any.extend({
             },
             jsonSchema(rule, res) {
 
-                res['x-constraint'] = { ...res['x-constraint'], sign: rule.args.sign };
+                if (rule.args.sign === 'positive') {
+                    res.exclusiveMinimum = 0;
+                }
+                else {
+                    res.exclusiveMaximum = 0;
+                }
+
                 return res;
             }
         },

test/json-schema.js

@@ -1070,39 +1070,38 @@ describe('jsonSchema', () => {
 
             Helper.validateJsonSchema(Joi.number().positive(), {
                 type: 'number',
-                'x-constraint': {
-                    sign: 'positive'
-                }
+                exclusiveMinimum: 0
             });
 
             Helper.validateJsonSchema(Joi.number().positive().only(), {
                 type: 'number',
-                'x-constraint': {
-                    sign: 'positive'
-                }
+                exclusiveMinimum: 0
             });
 
             Helper.validateJsonSchema(Joi.number().negative(), {
                 type: 'number',
-                'x-constraint': {
-                    sign: 'negative'
-                }
+                exclusiveMaximum: 0
             });
 
             Helper.validateJsonSchema(Joi.number().positive().multiple(3), {
                 type: 'number',
                 multipleOf: 3,
-                'x-constraint': {
-                    sign: 'positive'
-                }
+                exclusiveMinimum: 0
             });
 
             Helper.validateJsonSchema(Joi.number().multiple(3).positive(), {
                 type: 'number',
                 multipleOf: 3,
-                'x-constraint': {
-                    sign: 'positive'
-                }
+                exclusiveMinimum: 0
+            });
+        });
+
+        it('represents number.port() constraints', () => {
+
+            Helper.validateJsonSchema(Joi.number().port(), {
+                type: 'integer',
+                minimum: 0,
+                maximum: 65535
             });
         });