Haiden Taylor asciant

React - Functional error boundaries

Thanks to React hooks you have now happily turned all your classes into functional components.

Wait, all your components? Not quite. There is one thing that can still only be implemented using classes: Error boundaries.

There is just no functional equivalent for componentDidCatch and deriveStateFromError yet.

Proposed solution

I really liked @tjvantoll article Handling Failed HTTP Responses With fetch(). The one thing I found annoying with it, though, is that response.statusText always returns the generic error message associated with the error code. Most APIs, however, will generally return some kind of useful, more human friendly message in the body.

Here's a modification that will capture this message. The key is that rather than throwing an error, you just throw the response and then process it in the catch block to extract the message in the body:

fetch("/api/foo")
  .then( response => {
    if (!response.ok) { throw response }
    return response.json()  //we only get here if there is no error
 })

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Provider	Singleton	Instantiable	Configurable
Constant	Yes	No	No
Value	Yes	No	No
Service	Yes	No	No
Factory	Yes	Yes	No
Decorator	Yes	No?	No
Provider	Yes	Yes	Yes

	const { GraphQLServer } = require("graphql-yoga");
	const session = require("express-session");
	const { Prisma } = require("prisma-binding");
	const resolvers = require("./resolvers");

	const db = new Prisma({
	typeDefs: "src/generated/prisma.graphql", // the auto-generated GraphQL schema of the Prisma API
	endpoint: process.env.PRISMA_ENDPOINT, // the endpoint of the Prisma API (value set in `.env`)
	debug: true // log all GraphQL queries & mutations sent to the Prisma API
	// secret: process.env.PRISMA_SECRET, // only needed if specified in `database/prisma.yml` (value set in `.env`)

	import { Module, RequestMethod } from '@nestjs/common';
	import { MiddlewaresConsumer, NestModule } from '@nestjs/common/interfaces';
	import { TypeOrmModule } from '@nestjs/typeorm';
	import { MulterMiddleware } from './../common/middleware/multer.middleware';

	@Module({
	controllers: [..],
	components: [..]
	})
	export class ProfileModule implements NestModule {

	#!/bin/bash

	readonly lm75=0x48 # Slave address with A0, A1, and A2 set to 0v (ground).

	while [ $# -gt 0 ]
	do
	if [ "$1" == "-debug" ]
	then
	debug=true
	fi

	Gem
	https://github.com/mileszs/wicked_pdf

	Downloads
	https://code.google.com/p/wkhtmltopdf/downloads/list?can=1&q=

	Guides / Common issues
	http://snikt.net/blog/2012/04/26/wicked-pdf/
	https://gist.github.com/wrburgess/3778949
	https://github.com/mileszs/wicked_pdf/wiki/Background-PDF-creation-via-delayed_job-gem

	# lib/tasks/db.rake
	namespace :db do

	desc "Dumps the database to db/APP_NAME.dump"
	task :dump => :environment do
	cmd = nil
	with_config do \|app, host, db, user\|
	cmd = "pg_dump --host #{host} --username #{user} --verbose --clean --no-owner --no-acl --format=c #{db} > #{Rails.root}/db/#{app}.dump"
	end
	puts cmd

	# Main reference was lascarides' post at http://stackoverflow.com/questions/14743447/getting-pdf-from-wickedpdf-for-attachment-via-carrierwave

	# estimate.rb
	# ...
	has_attached_file :pdf,
	storage: :s3,
	s3_credentials: {
	access_key_id: ENV['AWS_ACCESS_KEY_ID'],
	secret_access_key: ENV['AWS_SECRET_ACCESS_KEY'],
	bucket: ENV['AWS_BUCKET']

Haiden Taylor asciant

React - Functional error boundaries

Proposed solution

Key to the Keys

Constant