Vali, Yet Another Validator

Vali, a purposefully tiny validator. Some 🔋🔋🔋 included, plus recipes on how to make more of them ☺️.

Description

Vali aims for the most things you could do with a minimal set of checks, therefore it has a small set of checks and an easy way to add your own checks, see the example and vali_test.go files.

You can also change the struct tag name being used (by creating a new Validator) and a few other bits, see Validator type definition.

It is pointer-insensitive, will always validate the value behind the pointer, that is, given:

Foo *string `validate:"required"`

passes if *Foo != "" NOT if Foo != nil.

It validates both public and private fields, as long as they have the validation tags.

Non-goals:

• slice/map dive;
• cross field checks;
• anything that needs a 3rd party dep.

Why? Complex validation reads better when is expressed as Go code, rather than in struct tags "perlisms".

Available Checks

Check	Description	Domain
required	must NOT be IsZero()	any
regex:<rx>	must match <rx>	string, Stringer
eq:<number>	must == number	CanInt, CanUint, CanFloat, CanLen
ne:<number>	must != number	same as eq
min:<number>	must be >= number	same as eq
max:<number>	must be <= number	same as eq
one_of:a|b|c	must be one of {a,b,c}	same as regex
uuid	32 (dash separated) hexdigits	same as regex
email	valid email address	string, Stringer
url	valid URL with scheme and host	string, Stringer
ipv4	valid IPv4 address	string, Stringer
ipv6	valid IPv6 address	string, Stringer
ip	valid IP address (v4 or v6)	string, Stringer
mac	valid MAC address	string, Stringer
domain	valid domain name	same as regex
isbn	valid ISBN-10 or ISBN-13	string, Stringer
alpha	letters only	same as regex
alphanum	letters and numbers only	same as regex
numeric	numbers only	same as regex
boolean	valid boolean representation	string, Stringer, numeric
creditcard	valid credit card number	string, Stringer, numeric
json	valid JSON format	string, Stringer, numeric
ascii	ASCII characters only	string, Stringer
lowercase	lowercase characters only	string, Stringer
uppercase	uppercase characters only	string, Stringer
hexadecimal	valid hexadecimal string	same as regex
base64	valid base64 string	same as regex
mongoid	valid MongoDB ObjectID	same as regex
rgb	valid RGB color	same as regex
rgba	valid RGBA color	same as regex
luhn	valid luhn string or number	string, Stringer, numeric
ssn	valid Social Security Number	same as regex
npi	valid NPI number	string, Stringer, numeric
<your_own>	you can easily add your own...	...

Multiple checks must be combined with a comma (,) extra space is forgiven, and empty checks are ignored i.e.: validate:"required,,,, uuid , one_of:foo|bar|baz" is fine, albeit unclean.

Both separators (between checks and between a check and its arguments) are configurable, whereas the separator between a check's arguments (the pipe symbol in the a|b|c example above) are up the each individual checker, the library doesn't care, it will just pass all the arguments as a string to the Checker func.

Sample Usage

s := struct {
	Foo struct {
		Bar string `validate:"required, one_of:foo|bar|baz"`
	}
	email string `validate:"required,email"`
}{}

if err := vali.Validate(s); err != nil {
    fmt.Println("oh noes!...")
}

Documentation

• this README;
• the example file;
• the code documentation and
• the tests.