locona / validator

:100:Go Struct and Field validation, including Cross Field, Cross Struct, Map, Slice and Array diving

Package validator

Package validator implements value validations for structs and individual fields based on tags.

It has the following unique features:

• Cross Field and Cross Struct validations by using validation tags or custom validators.
• Slice, Array and Map diving, which allows any or all levels of a multidimensional field to be validated.
• Handles type interface by determining it's underlying type prior to validation.
• Handles custom field types such as sql driver Valuer see Valuer
• Alias validation tags, which allows for mapping of several validations to a single tag for easier defining of validations on structs
• Extraction of custom defined Field Name e.g. can specify to extract the JSON name while validating and have it available in the resulting FieldError
• Customizable i18n aware error messages.
• Default validator for the gin web framework; upgrading from v8 to v9 in gin see here

Installation

Use go get.

go get gopkg.in/go-playground/validator.v9

Then import the validator package into your own code.

import "gopkg.in/go-playground/validator.v9"

Error Return Value

Validation functions return type error

They return type error to avoid the issue discussed in the following, where err is always != nil:

• http://stackoverflow.com/a/29138676/3158232
• go-playground#134

Validator only InvalidValidationError for bad validation input, nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not check if error is InvalidValidationError ( if necessary, most of the time it isn't ) type cast it to type ValidationErrors like so:

err := validate.Struct(mystruct)
validationErrors := err.(validator.ValidationErrors)

Usage and documentation

Please see http://godoc.org/gopkg.in/go-playground/validator.v9 for detailed usage docs.

Examples:

• Simple
• Custom Field Types
• Struct Level
• Translations & Custom Errors
• Gin upgrade and/or override validator
• wash - an example application putting it all together

Benchmarks

Run on MacBook Pro (15-inch, 2017) Go version go1.9.1 linux/amd64

go test -bench=. -benchmem=true
BenchmarkFieldSuccess-8                                       	20000000	        87.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkFieldSuccessParallel-8                               	50000000	        26.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkFieldFailure-8                                       	 5000000	       299 ns/op	     208 B/op	       4 allocs/op
BenchmarkFieldFailureParallel-8                               	20000000	       100 ns/op	     208 B/op	       4 allocs/op
BenchmarkFieldDiveSuccess-8                                   	 2000000	       645 ns/op	     201 B/op	      11 allocs/op
BenchmarkFieldDiveSuccessParallel-8                           	10000000	       198 ns/op	     201 B/op	      11 allocs/op
BenchmarkFieldDiveFailure-8                                   	 2000000	       876 ns/op	     412 B/op	      16 allocs/op
BenchmarkFieldDiveFailureParallel-8                           	 5000000	       268 ns/op	     413 B/op	      16 allocs/op
BenchmarkFieldCustomTypeSuccess-8                             	10000000	       228 ns/op	      32 B/op	       2 allocs/op
BenchmarkFieldCustomTypeSuccessParallel-8                     	20000000	        70.0 ns/op	      32 B/op	       2 allocs/op
BenchmarkFieldCustomTypeFailure-8                             	 5000000	       286 ns/op	     208 B/op	       4 allocs/op
BenchmarkFieldCustomTypeFailureParallel-8                     	20000000	        95.6 ns/op	     208 B/op	       4 allocs/op
BenchmarkFieldOrTagSuccess-8                                  	 2000000	       857 ns/op	      16 B/op	       1 allocs/op
BenchmarkFieldOrTagSuccessParallel-8                          	 3000000	       397 ns/op	      16 B/op	       1 allocs/op
BenchmarkFieldOrTagFailure-8                                  	 3000000	       495 ns/op	     224 B/op	       5 allocs/op
BenchmarkFieldOrTagFailureParallel-8                          	 5000000	       376 ns/op	     224 B/op	       5 allocs/op
BenchmarkStructLevelValidationSuccess-8                       	10000000	       226 ns/op	      32 B/op	       2 allocs/op
BenchmarkStructLevelValidationSuccessParallel-8               	20000000	        68.4 ns/op	      32 B/op	       2 allocs/op
BenchmarkStructLevelValidationFailure-8                       	 3000000	       497 ns/op	     304 B/op	       8 allocs/op
BenchmarkStructLevelValidationFailureParallel-8               	10000000	       170 ns/op	     304 B/op	       8 allocs/op
BenchmarkStructSimpleCustomTypeSuccess-8                      	 3000000	       420 ns/op	      32 B/op	       2 allocs/op
BenchmarkStructSimpleCustomTypeSuccessParallel-8              	20000000	       124 ns/op	      32 B/op	       2 allocs/op
BenchmarkStructSimpleCustomTypeFailure-8                      	 2000000	       681 ns/op	     424 B/op	       9 allocs/op
BenchmarkStructSimpleCustomTypeFailureParallel-8              	10000000	       244 ns/op	     440 B/op	      10 allocs/op
BenchmarkStructFilteredSuccess-8                              	 2000000	       659 ns/op	     288 B/op	       9 allocs/op
BenchmarkStructFilteredSuccessParallel-8                      	10000000	       211 ns/op	     288 B/op	       9 allocs/op
BenchmarkStructFilteredFailure-8                              	 3000000	       482 ns/op	     256 B/op	       7 allocs/op
BenchmarkStructFilteredFailureParallel-8                      	10000000	       162 ns/op	     256 B/op	       7 allocs/op
BenchmarkStructPartialSuccess-8                               	 3000000	       564 ns/op	     256 B/op	       6 allocs/op
BenchmarkStructPartialSuccessParallel-8                       	10000000	       180 ns/op	     256 B/op	       6 allocs/op
BenchmarkStructPartialFailure-8                               	 2000000	       779 ns/op	     480 B/op	      11 allocs/op
BenchmarkStructPartialFailureParallel-8                       	 5000000	       268 ns/op	     480 B/op	      11 allocs/op
BenchmarkStructExceptSuccess-8                                	 2000000	       879 ns/op	     496 B/op	      12 allocs/op
BenchmarkStructExceptSuccessParallel-8                        	10000000	       163 ns/op	     240 B/op	       5 allocs/op
BenchmarkStructExceptFailure-8                                	 2000000	       734 ns/op	     464 B/op	      10 allocs/op
BenchmarkStructExceptFailureParallel-8                        	 5000000	       259 ns/op	     464 B/op	      10 allocs/op
BenchmarkStructSimpleCrossFieldSuccess-8                      	 3000000	       432 ns/op	      72 B/op	       3 allocs/op
BenchmarkStructSimpleCrossFieldSuccessParallel-8              	10000000	       129 ns/op	      72 B/op	       3 allocs/op
BenchmarkStructSimpleCrossFieldFailure-8                      	 2000000	       671 ns/op	     304 B/op	       8 allocs/op
BenchmarkStructSimpleCrossFieldFailureParallel-8              	10000000	       229 ns/op	     304 B/op	       8 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldSuccess-8           	 2000000	       628 ns/op	      80 B/op	       4 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldSuccessParallel-8   	10000000	       182 ns/op	      80 B/op	       4 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldFailure-8           	 2000000	       872 ns/op	     320 B/op	       9 allocs/op
BenchmarkStructSimpleCrossStructCrossFieldFailureParallel-8   	 5000000	       267 ns/op	     320 B/op	       9 allocs/op
BenchmarkStructSimpleSuccess-8                                	 5000000	       274 ns/op	       0 B/op	       0 allocs/op
BenchmarkStructSimpleSuccessParallel-8                        	20000000	        79.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkStructSimpleFailure-8                                	 2000000	       647 ns/op	     424 B/op	       9 allocs/op
BenchmarkStructSimpleFailureParallel-8                        	10000000	       224 ns/op	     424 B/op	       9 allocs/op
BenchmarkStructComplexSuccess-8                               	 1000000	      1557 ns/op	     128 B/op	       8 allocs/op
BenchmarkStructComplexSuccessParallel-8                       	 3000000	       473 ns/op	     128 B/op	       8 allocs/op
BenchmarkStructComplexFailure-8                               	  300000	      4373 ns/op	    3041 B/op	      53 allocs/op
BenchmarkStructComplexFailureParallel-8                       	 1000000	      1554 ns/op	    3041 B/op	      53 allocs/op

Complementary Software

Here is a list of software that complements using this library either pre or post validation.

• form - Decodes url.Values into Go value(s) and Encodes Go value(s) into url.Values. Dual Array and Full map support.
• mold - A general library to help modify or set data within data structures and other objects

How to Contribute

Make a pull request...

License

Distributed under MIT License, please see license file within the code for more details.