val.ts

import {Config} from "./Config";
import {Describe} from "./Describe";

export function val(name: string, _: any): Val {
    return new Val(name, _);
}

export class Val {
    name: string;
    value: any;

    constructor(name: string, value: any) {
        this.name = name;
        this.value = value;
    }

    /**
     * These 3 steps will be applied to format a value in Examples and Tables:
     *
     * 1) If a [Config.transformDescribe] was provided, it will be used to format the value.
     *
     * 2) Next, if the value is null, return 'NULL'.
     *
     * 3) Next, if the value implements the [BddDescribe] interface, or if it has a
     * [describe] method, it will be used to format the value.
     *
     * 4) Last, we'll call the value's [toString] method.
     */
    toString(config: Config = Config._default): string {
        let _value = this.value;

        // 1)
        if (config.transformDescribe) {
            _value = config.transformDescribe(this.value) || _value;
        }

        // 2)
        if (_value === null) return 'NULL';
            //
        // 3)
        else if ((<Describe>_value).describe) {
            let description = (<Describe>_value).describe();
            return (description === null) ? 'NULL' : description.toString();
        }
            //
        // 4)
        else
            return _value.toString();
    }
}