deterministically generate simple data from json schema's
ISC License
Generate simple data that matches a json schema.
All libraries that generate data from a json-schema I could find generate random data that conforms to a json schema. This is nice for testing but is not well-suited for generating default data for forms for example.
json-schema-empty
fills another niche. The data it generates
conforms to the following qualities:
To install json-schema-empty
, run:
npm install json-schema-empty --save
The api is simple:
import empty from 'json-schema-empty';
// var empty = require('json-schema-empty').default; // when not using es6
var schema = {
type: 'object'
, properties: {
foo: {
type: 'integer'
, minimum: 12
, multipleOf: 5
}
, bar: {
type: 'array'
, items: { type: 'integer' }
, minItems: 3
}
, baz: {
type: 'string',
minLength: 5
}
}
, required: [ 'foo', 'bar', 'baz' ]
};
console.log(empty(schema));
// logs:
// {
// foo: 15,
// bar: [ 0, 0, 0 ],
// baz: ''
// }
string: because it impossible to guess what the string
content should be, even when patterns and length limits are given,
a string schema always results in the empty string: ''
.
integer: json-schema-empty
tries to satisfy the minimum
, maximum
and multipleOf
constraints whenever possible wth the additional property
that, when it is possible, 0
is returned.
number: just follows the integer
schema.
object: tries to create a minimal object with as few keys as possible.
Only keys that are in the required
array are generated.
Object size is ignored completely, for the same reason that the strings are empty: we cannot guess the keys.
array: when the item
type is given, and minItems
is given,
the shortest array that matches this is generated. It also works
when items
is a tuple. maxItems
is ignored. Whenever possible,
the empty array is returned.
boolean: always results in false
.
null: always results in null
.
oneOf, anyOf: selects one of the accepted types and goes from there.
allOf: json-schema-empty
merges all schemas and works from that schema
to generate a value.
enum: selects the first possible value.
$ref
: just works!
Whenever specified, json-schema-empty
uses the default
value (even if it
does not match the schema).
This code is licensed under the ISC license