Feature request: Add possibility to register custom formats #152
Description
Feature
We can already enable format validation when creating a validator. Currently, we have some built-in formats (for example, IPv4, IPv6, email, etc.). But we can't define custom formats (for example, phone numbers, country codes, etc.) or override existing ones (like email). Underlying library santhosh-tekuri/jsonschema have support for such thing via func (*Compiler) RegisterFormat.
Proposal
Add new field to config/config.go ValidationOptions that will hold information about new formats.
type ValidationOptions struct {
RegexEngine jsonschema.RegexpEngine
FormatAssertions bool
ContentAssertions bool
Formats map[string]func(v any) error
}Add new function to add custom format in file config/config.go.
// WithCustomFormat adds custom formats and their validators that checks for custom 'format' assertions
func WithCustomFormat(name string, validator func(v any) error) Option {
return func(o *ValidationOptions) {
// todo check that map is initialized
o.Formats[name] = validator
}
}Also, we have to add register of custom formats in jsonschema.Compiler.
// ConfigureCompiler configures a JSON Schema compiler with the desired behavior.
func ConfigureCompiler(c *jsonschema.Compiler, o *config.ValidationOptions) {
if o == nil {
// Sanity
return
}
// nil is the default so this is OK.
c.UseRegexpEngine(o.RegexEngine)
// Enable Format assertions if required.
if o.FormatAssertions {
c.AssertFormat()
}
// Content Assertions
if o.ContentAssertions {
c.AssertContent()
}
// Register custom formats
for n, v := range o.Formats {
c.RegisterFormat(&jsonschema.Format{
Name: n,
Validate: v,
})
}
}This should be enough to register custom formats. This functionality still relys on FormatAssertions enabled and it's fine.