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object

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This function validates that the input is an object and uses the provided schemas for the required and optional properties. The schemas are objects where the keys define the property name and the associated value defines the rule to validate the input property's value.

This function can throw the rulr.InvalidObjectError for invalid objects. All errors thrown by the schema rules will be wrapped in rulr.ValidationErrors. For valid data, this function returns an object with only the properties defined in the schemas.

Whilst adding verbosity compared to other validation packages, the decision for this function to take required and optional schemas separately enables the type of the object to correctly use the ? functionality for the object property rather than resulting in a property with SomeType | undefined as the type. It also achieves this without adding processing complexity to the object rule and allows a bail option to be provided without passing more parameters to the object rule.

import * as rulr from 'rulr'

const constrainToExample = rulr.object({
	required: {
		requiredExample: rulr.number,
	},
	optional: {
		optionalExample: rulr.number,
	},
	bail: true, // Throws at first error. Defaults to false.
})

type Example = rulr.Static<typeof constrainToExample>
// {
//   requiredExample: number;
//   optionalExample?: number;
// }

// Valid
const example1: Example = constrainToExample({
	requiredExample: 1,
})

// Valid
const example2: Example = constrainToExample({
	requiredExample: 1,
	optionalExample: 1,
})

// Invalid
const example3: Example = constrainToExample([])

// Invalid
const example4: Example = constrainToExample({
	requiredExample: '1',
})

// Invalid
const example5: Example = constrainToExample({
	optionalExample: 1,
})