UnhandledPromiseRejectionWarning TypeError：无法读取未定义的属性“property”

Question

我有下面的代码，它尝试读取一个txt，将它转换为一个数组，然后转换为json，将它保存在一个db中，但是当调用控制器时，我尝试运行SaveReferences函数，它向我发送了这个错误：UnhandledPromiseRejectionWarning：TypeError：无法读取未定义的属性'service'

另外，请发送以下信息：Promise{TypeError：无法读取ReferenceController.Saved处GettingInfo.SavereFerences处GettingInfo.ReadFile处未定义的属性“service”

  export interface Dataconf{
        service:number;
        name:string;
        ref:string
    }
    
    export class GettingInfo {
    
        constructor(private referenceService: ReferenceService) {
        }
    
        Readfile = () => {
    
            const file = path.resolve(__dirname, '../../../dist/entity/PRUEBA.txt')
            try {
                const data = fs.readFileSync(file, 'utf-8');
                const lines = data.split("\n")
                let values = []
                let bi = []
                lines.forEach(line => {
                    line.trim()
                    values = line.split("\|", 6).map(a => a.trim());
                    bi.push(values)
                    console.log(bi)
     })
                const convert = this.ConditionData(bi)
                console.log(convert)
                const save = this.SaveReferences(convert)
                console.log(save)
    
            } catch (err) {
                console.error(err), "something has happened to the file";
            }
        }
    
        ConditionData(values): Array<Dataconf> {
            let resultado = [];
            values.forEach(arreglo => {
                let ref = 'ref';
                for (let i = 3; i < arreglo.length; i++) {
                    if (arreglo[i].length > 0) {
                        let obj = {
                            service: parseInt(arreglo[0]),
                            name: arreglo[1]
                        }
                        obj[ref] = arreglo[i];
                        resultado.push(obj);
                    }
                }
            });
            console.log("resultado funcionConditionData", resultado)
            return resultado;
        }

async SaveReferences(data: Array<Dataconf>) {
        console.log("array", data)
        let i
        let orderField = 0;
        let helper = data[i].service;
        for (i = 0; i <= data.length; i++) {
            if (data[i].service != helper) {
                helper = data[i].service;
                orderField = 0
                try {
                    let res = await this.referenceService.createReference({
                        service: data[i].service,
                        name: `ref${i}`,
                        label: data[i].ref,
                        longitud: 0,
                        order: orderField
                    });
                } catch (e) {
                    console.error(e);
                }
            }
        }
        return data;
    }

Answer 1

在SaveReferences中，第4行i未定义

let helper = data[i].service;

应该是

let helper;

在for循环内部分配helper时