lib/src/forms/rules/inference.ts

import {infer as inferUtil} from '../../util'
import {ValidationResult} from "./types";

export namespace Cast {
    /** Attempt to infer the native type of a string value. */
    export function infer(fieldName: string, inputValue: any): ValidationResult {
        return {
            valid: true,
            castValue: typeof inputValue === 'string' ? inferUtil(inputValue) : inputValue,
        }
    }

    /**
     * Casts the input value to a boolean.
     * Note that this assumes the value may be boolish. The strings "true", "True",
     * "TRUE", and "1" evaluate to `true`, while "false", "False", "FALSE", and "0"
     * evaluate to `false`.
     * @param fieldName
     * @param inputValue
     */
    export function boolean(fieldName: string, inputValue: any): ValidationResult {
        let castValue = !!inputValue

        if ( ['true', 'True', 'TRUE', '1'].includes(inputValue) ) castValue = true
        if ( ['false', 'False', 'FALSE', '0'].includes(inputValue) ) castValue = false

        return {
            valid: true,
            castValue,
        }
    }

    /** Casts the input value to a string. */
    export function string(fieldName: string, inputValue: any): ValidationResult {
        return {
            valid: true,
            castValue: String(inputValue),
        }
    }

    /** Casts the input value to a number, if it is numerical. Fails otherwise. */
    export function numeric(fieldName: string, inputValue: any): ValidationResult {
        if ( !isNaN(parseFloat(inputValue)) ) {
            return {
                valid: true,
                castValue: parseFloat(inputValue)
            }
        }

        return {
            valid: false,
            message: 'must be numeric',
        }
    }

    /** Casts the input value to an integer. Fails otherwise. */
    export function integer(fieldName: string, inputValue: any): ValidationResult {
        if ( !isNaN(parseInt(inputValue)) ) {
            return {
                valid: true,
                castValue: parseInt(inputValue)
            }
        }

        return {
            valid: false,
            message: 'must be an integer',
        }
    }
}