JustenRickert

import React from 'react';

function HexagonSvg({ attrs = {}, position: [x0, y0], length }) {
  const p1 = [-1 / 3, 0];
  const p2 = [-1 / 6, -1 / 3];
  const p3 = [1 / 6, -1 / 3];
  const p4 = [1 / 3, 0];
  const p5 = [1 / 6, 1 / 3];
  const p6 = [-1 / 6, 1 / 3];
  const M = ([x, y]) => `M ${x0 + length * x} ${y0 + length * y}`;

JustenRickert

module.exports = {
  '*.js': absolutePaths => {
    return `jest ${absolutePaths.map(filename => filename.slice(0, -3) + '.test.js').join(' ')}`
  }
}

JustenRickert

import fs from "fs";
import { uniq } from "lodash";
import { parse } from "@babel/parser";
import traverse from "@babel/traverse";

const getRelevantFiles = (filename, relevantFiles = []) => {
  if (relevantFiles.includes(filename)) return relevantFiles;
  const ast = parse(fs.readFileSync(filename, "utf-8"));
  traverse(ast, {
    ImportDeclarations(path) {

JustenRickert

{
  "scripts": {
    "test": "jest"
  },
  "lint-staged": {
    "*.js": [
      "prettier --write",
      "git add"
    ]
  },

JustenRickert

class WorkRunner {
  constructor(fork, { actionCreator, messageCreator }) {
    this.fork = fork;
    this.actionCreator = actionCreator;
    this.messageCreator = messageCreator;

    this.fork.on("message", this.actionCreator);
  }

  send(msg) {

JustenRickert

import { isArray, isString, isFunction } from "lodash";

const { performance } = require("perf_hooks");

type Parameters<Fn> = Fn extends (...args: infer T) => any ? T : never;

const trampoline = <Fn extends (...args: any[]) => any>(
  fn: Fn,
  ...args: Parameters<Fn>
) => {

JustenRickert

public class RoachPopulation {
    private static double initialPopulation;

    RoachPopulation(double initialPopulation) {
        this.initialPopulation = initialPopulation;
    }

    public void waitForIt() {
        initialPopulation *= 2.0;
    }

JustenRickert

updateIn/updateInto

By Procedure

const byProcedure = <T>(arrays: T[][], update: { i: number; j: number; value: T }) => {
  const retArr: T[][] = [];
  for (const i in arrays) {
    retArr.push([]);
    for (const j in arrays[i]) {
      if (Number(i) === update.i && Number(j) === update.j) {

JustenRickert

The Problem

JavaScript doesn't want to support mutual recursion within our testing environment. So, the below function fails while running our test suite.

const selectPersistedContext = (state: RootState) => {
  const advisors = selectAdvisors(state); // selectAdvisors undefined
  const context = selectPersistedContext(state); // selectPersistedContext undefined
  const { fmid } = context;
  if (fmid) {
    const advisor = advisors.find(advisor => advisor.fmid === fmid);

JustenRickert

  (setq org-capture-templates
        '(("n" "Task" entry (file+headline "~/life/org/inbox.org"
                                           "Inbox")
           "* TODO %? \n%i  - Task created on %U \\\\" :empty-lines 1)
          ("j" "Journal" entry (file+datetree "~/life/org/journal.org")
           "* %<%H:%M> %?\n" :empty-lines 1)))