spion

type ExtractValuesRecusrively<T> = T extends FormState<infer U>
  ? { [K in keyof U]: ExtractValuesRecusrively<U[K]> }
  : T extends FieldState<infer V>
  ? V
  : never;

// vs

type ExtractValuesRecusrively<State> = State extends FormState<infer InnerForm>
  ? { [FieldKey in keyof InnerForm]: ExtractValuesRecusrively<InnerForm[FieldKey]> }

spion

let types = ../types.dhall sha256:e48e21b807dad217a6c3e631fcaf3e950062310bfb4a8bbcecc330eb7b2f60ed

let defaults = ../defaults.dhall sha256:4450e23dc81975d111650e06c0238862944bf699537af6cbacac9c7e471dfabe

let deployment : types.Deployment = defaults.Deployment // { 
  metadata = defaults.ObjectMeta // { name = "nginx" }, 
  spec = Some ( defaults.DeploymentSpec //  { 
    replicas = Some 2, 
    template = defaults.PodTemplateSpec // { 
      metadata = defaults.ObjectMeta // { 

spion

import * as Lint from 'tslint';
import * as ts from 'typescript';

import { inspect } from 'util';

/**
 * This rule will ensure that methods marked with the "@expose" decorator must be declared in at
 * least one interface implemented by the class. It will also ensure that the return type of this
 * method has no excess properties compared to those specified in the interface
 */

spion

type PromiseState<T> = {
  state: 'fulfilled', value: T
} | {state: 'pending'} | {state: 'rejected', error: Error};


let wm = new WeakMap<Promise<any>, PromiseState<any>>()

export function asyncCase<T, U>(promise: Promise<T>, handlers: {
  pending?: () => U;
  fulfilled?: (t: T) => U;

spion

/**
 * Implementation of promise dialogs
 */
import { observable, action } from 'mobx';
import * as React from 'react';
import { AppSingleton } from '@h4bff/core';
import { AppContext } from '../router';
import { observer } from 'mobx-react';

interface Resolver<T> {

spion

/**
 * Allocate a callback based resource, safely
 *
 * Example:
 * function connectionResource(url) {
 *   return { acquire: async () => pg.connect(url), dispose: async conn => conn.dispose() }
 * }
 * usingPromise(connectionResource(process.env.DATABASE_URL), async conn => {
 *   await conn.query(...);
 *   do other things

spion

In JavaScript, functions have arguments. We can name those arguments so that we can access the values we pass to those functions

function add(a, b) {
  return a + b;
}

We can call these functions normally:

spion

{"output":{"equalizer":{"state":"true","num-bands":"6","input-gain":"-2","output-gain":"0","split-channels":"false","left":{"band0":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"-7.4","frequency":"222.0","q":"0.230"},"band1":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"4.0","frequency":"30.0","q":"0.470"},"band2":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"-2.2","frequency":"1686.0","q":"1.520"},"band3":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"2.0","frequency":"3090.0","q":"2.080"},"band4":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"-3.1","frequency":"6888.0","q":"1.000"},"band5":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"-1.1","frequency":"10550.0","q":"3.470"}},"right":{"band0":{"type":"Bell","mode":"RLC (BT)","slope":"x1","solo":"false","mute":"false","gain":"-7.4","fre

spion

import React, { useState, useEffect } from 'react';

function useFriendStatus(friendID) {
  const [isOnline, setIsOnline] = useState(null);

  useEffect(() => {
    function handleStatusChange(status) {
      setIsOnline(status.isOnline);
    }

spion

Database testing of web applications

Testing database code is tricky. There seems to be a lack of resources on this topic (or I'm not looking at the right places). The resources I found so far focus on mocking the data access layer. This however is insufficient, as there are scenarios where it doesn't do what we want.

Mocking

Most of the resources suggest mocking techniques. Mocking is a technique where we program an object to behave as if it were another object, without implementing the underlying mechanisms necessary to re-create the whole thing. For example, this is how we would mock a database access layer based on SQL queries.

We have the function createFriends which we want to test: