#JSON Schema Basics

schema-dsl uses JSON Schema Draft 7 as its baseline and keeps a few internal fields for its validators. It also executes selected newer applicator keywords, including minContains / maxContains; this extension does not imply full Draft 2019-09 or 2020-12 support.

Common fields:

• type
• properties
• required
• minLength / maxLength
• minimum / maximum
• format
• enum
• items
• additionalItems
• contains with schema-dsl minContains / maxContains range support

When outputting pure JSON Schema, please use toJsonSchema().

const emailField = s('email!').label('mailbox');

emailField.toSchema();
// Contains internal fields such as _label / _customMessages

emailField.toJsonSchema();
// Pure JSON Schema, suitable for exporting to external systems

const objectSchema = s({
	email: emailField,
	age: s('number:18-100')
});
// s({... }) entry directly returns Draft 7 style object

const containsRangeSchema = {
	type: 'array',
	contains: { type: 'number' },
	minContains: 2,
	maxContains: 3
};
// Executed consistently by validate(), validateAsync(), and compile().

#Corresponding sample file

Example entry: json-schema-basics.ts Description: Directly compare the output differences between toSchema() and toJsonSchema(), and display the JSON Schema structure returned by the object entry.