Question

我正在用角度8编写测试，以检查是否已调用component方法。就我而言，我正在检查方法调用removeSettlementConfirmation。我不确定callThrough或返回空obserable是否是最好的测试方法如果该方法称为

如果我写

spyOn(component, 'removeSettlementConfirmation').and.callThrough();

我收到错误TypeError：无法读取未定义的属性'subscribe'

但是如果我写

spyOn(component, 'removeSettlementConfirmation').and.returnValue({ subscribe: () => {} });

错误消失了。

测试这种方法的正确方法是什么？

单元测试

fit('removeSettlementConfirmation should be called', () => {
        let clientCompanyOpiId = 10;
        let title = `Delete Settlement Account`;
        let message = `Are you sure you want to delete this OPI account?`;
        let testConfirmModal = ({
            title: 'Delete Settlement Account',
            message: 'Are you sure you want to delete this OPI account?'
        } as ConfirmModalComponent);
        component.confirmModal = testConfirmModal;
        spyOn(component, 'removeSettlementConfirmation').and.returnValue({ subscribe: () => {} });
        spyOn(clientService, 'getNumberOfTradesWhereOPIIsSetOn').and.returnValue({ subscribe: () => {} });
        component.removeSettlementConfirmation(clientCompanyOpiId);
        expect(component.removeSettlementConfirmation).toHaveBeenCalled();
    });

组件代码

removeSettlementConfirmation(clientCompanyOpiId: number): void {
        this.clientService.getNumberOfTradesWhereOPIIsSetOn(clientCompanyOpiId)
            .subscribe(
                data => {
                    const assignedTrades = data;
                    const trades = +assignedTrades > 1 ? 's' : '';
                    const message = assignedTrades
                        ? `This OPI account is set on ${assignedTrades} trade${trades}. Are you sure you want to delete it?`
                        : `Are you sure you want to delete this OPI account?`;
                    const title = `Delete Settlement Account`;
                    this.confirmModal.openModal(title, message, clientCompanyOpiId);
                },
                error => {
                    this.alertService.showMessage("Error", "Unable to get Associated Trades for Settlement Account", MessageSeverity.error);
                });
    }

Answer 1

and.returnValue():

可以使间谍返回一个预设值/固定值（无需使用and.callThrough())调用实际方法。这可以通过将spyOn()函数与and.returnValue().链接来实现。

    fit('removeSettlementConfirmation should be called', () => {
                let clientCompanyOpiId = 10;
                let title = `Delete Settlement Account`;
                let message = `Are you sure you want to delete this OPI account?`;
                let testConfirmModal = ({
                    title: 'Delete Settlement Account',
                    message: 'Are you sure you want to delete this OPI account?'
                } as ConfirmModalComponent);
                component.confirmModal = testConfirmModal;
                spyOn(component, 'removeSettlementConfirmation').and.returnValue("mock response"); // with returnValue() you should return the actual mockResponse
                spyOn(clientService, 'getNumberOfTradesWhereOPIIsSetOn').and.returnValue("test"); // with returnValue() you should return the actual mockResponse
                component.removeSettlementConfirmation(clientCompanyOpiId);
                expect(component.removeSettlementConfirmation).toHaveBeenCalled();

                // you can verify by calling the methods and expected response
                const response = component.removeSettlementConfirmation();
                expect(response).toEqaul("mock response");
            });

茉莉花测试错误：TypeError：无法读取未定义的属性“订阅”

1 个答案: