import { BehaviorSubject, forkJoin } from 'rxjs'

export const tableConfig: any[] = [{
    tableName: 'TableOne'
},
{
    tableName: 'TableTwo'
},
{
    tableName: 'TableThree'
}];

const exampleApiTableData: any = {
    TableOne: [],
    TableTwo: [],
    TableThree: [],
}

export const pullTableData = (tableName: string): Promise<any[]> => { //async Promise function 1
    return new Promise((resolve, reject) => {
        // Here is a async api call with some more logic but to make it simple and short giving such an example
        setTimeout(() => {
            resolve(exampleApiTableData[tableName]);
        }, 1000);
    })
}

export const buildNewTable = (tableOne: any[], tableTwo: any []): Promise<any[]> => { // Promise function 2
    return new Promise((resolve, reject) => {
        //simplified example
        resolve(tableOne.concat(tableTwo));
    })
}

export const getTables = (): Promise<any> => { // Master
    return new Promise((resolve, reject) => {
        const errors: string[] = [];
        const allTableData$: any[] = [];
        const observableNames: any = {};

        tableConfig.forEach(table => {
            observableNames[table.tableName + 'Source'] = new BehaviorSubject<string[]>([]);
            observableNames[table.tableName] = observableNames[table.tableName + 'Source'].asObservable();
            allTableData$.push(observableNames[table.tableName]);
            pullTableData(table.tableName).then((result: any[]) => {
                observableNames[table.tableName + 'Source'].next(result);
                observableNames[table.tableName + 'Source'].complete();
            }).catch((error: any) => {
                errors.push(error);
                observableNames[table.tableName + 'Source'].next(error);
                observableNames[table.tableName + 'Source'].complete();
            })
        });

        forkJoin(allTableData$).subscribe((results: any) => {
            if (errors.length > 0) reject(errors);
            buildNewTable(observableNames.TableOneSource.value, observableNames.TableTableTwoSource.value).then((result: any[]) => {
                // console.log(result);
                resolve(result);
            }).catch((error: any) => {
                // console.log(error);
                reject(error);
            });
        });
    });
}

import * as tableMethods from './index'

describe(`Test the Table methods`, () => {
    test(`it should return and error`, () => {
        const expectedError = `I'm an error`
        jest.fn(tableMethods.pullTableData).mockRejectedValue(expectedError);

        return tableMethods.getTables().then((data: any) => {

        }).catch((error: any) => {
            expect(error).toBe(expectedError);
        })
    })
})