Dima Khadorkin khadorkin

Profiler

React 16.4 will introduce a new Profiler component (initially exported as React.unstable_Profiler) for collecting render timing information in order to measure the "cost" of rendering for both sync and async modes.

Profiler timing metrics are significantly faster than those built around the User Timing API, and as such we plan to provide a production+profiling bundle in the future. (The initial release will only log timing information in DEV mode, although the component will still render its children- without timings- in production mode.)

How is it used?

Profiler can be declared anywhere within a React tree to measure the cost of rendering that portion of the tree. For example, a Navigation component and its descendants:

The flow

husky (setup git commit hooks) -> lint-stages (run specific commands by file type) -> imagemin (minify files)

git add -A
git commit # It will compress your images into git repo now

Since the images is now fully compressed, no extra steps is required by webpack/browserify……whatever.

New Build System Tricks

Command Line

alias xcbuild=$(xcode-select -p)/../SharedFrameworks/XCBuild.framework/Versions/A/Support/xcbuild
# THIS DOESNT WORK YET: xcbuild openIDEConsole  # … then switch to Xcode ➡️
xcbuild showSpecs
xcbuild build <foo.pif> [—target <target>]

	# this should be the folder name under `ios` for your project
	project_name = 'MyProject'

	# NOTE: This is meant to be run on CI where it changes everything before building the app.
	# Usage:
	# `RN_RELEASE_TYPE=beta fastlane prep_release_type` (on CI these ENV variables should be set via the UI)
	# Available release types: alpha, beta, production (default)
	#
	# If you're trying this script out locally, make sure you have ImageMagick installed, and discard the changes via git when you're done.
	desc "Updates the app identifier, display name and icon for alpha, beta, and production releases"

	// Source: https://github.com/react-community/react-native-platform-touchable
	import React, { PureComponent, ReactNode } from 'react'
	import {
	BackgroundPropType,
	Platform,
	StyleProp,
	TouchableNativeFeedback,
	TouchableNativeFeedbackProperties,
	TouchableNativeFeedbackStatic,
	TouchableOpacity,

 import React, { Component, createContext }  from 'react'
 function initStore(store) {
     const Context = createContext();
     class Provider extends React.Component {
         constructor() {
             super();
             this.state = store.initialState;
         }

	const JSZip = require('jszip')
	const { parseBuffer } = require('bplist-parser')
	const { isObject, each, find } = require('lodash')

	const parseArchivedValue = value => {
	return parseBuffer(new Buffer(value, 'base64'))
	}

	const parseArchivedString = obj => {
	const { $objects } = parseArchivedValue(

	// Adapted from http://lukajcb.github.io/blog/functional/2018/01/03/optimizing-tagless-final.html

	import { Applicative, Applicative1 } from 'fp-ts/lib/Applicative'
	import { Apply, Apply1, Apply2C, applySecond, liftA4 } from 'fp-ts/lib/Apply'
	import * as array from 'fp-ts/lib/Array'
	import * as const_ from 'fp-ts/lib/Const'
	import { HKT, Type, Type2, URIS, URIS2 } from 'fp-ts/lib/HKT'
	import { IO, io, URI as IOURI } from 'fp-ts/lib/IO'
	import { Option, some } from 'fp-ts/lib/Option'
	import { getProductSemigroup, Semigroup } from 'fp-ts/lib/Semigroup'

	import React from 'react';

	const ConditionalWrap = ({condition, wrap, children}) => condition ? wrap(children) : children;

	const Header = ({shouldLinkToHome}) => (
	<div>
	<ConditionalWrap
	condition={shouldLinkToHome}
	wrap={children => <a href="/">{children}</a>}
	>

	// Ignore those pesky styles
	require('ignore-styles');

	// Set up babel to do its thing... env for the latest toys, react-app for CRA
	require('babel-register')({
	ignore: /\/(build\|node_modules)\//,
	presets: ['env', 'react-app']
	});

	// Now that the nonsense is over... load up the server entry point