Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
JavaScript Error Handling
Search
Jake Trent
March 19, 2014
Programming
0
100
JavaScript Error Handling
Points mostly from a talk originally given at #MWRC by @xjamundx
Jake Trent
March 19, 2014
Tweet
Share
More Decks by Jake Trent
See All by Jake Trent
How We Make The Design System
jaketrent
4
1.4k
Accessibility in the Pluralsight Design System
jaketrent
0
730
Design System Support Beyond React
jaketrent
0
660
Getting into Frontend Dev Today
jaketrent
0
620
Encourage Great Combinations
jaketrent
0
730
Getting into React
jaketrent
0
730
Ways to Compose in React
jaketrent
0
71
Anatomy of a Blot Post
jaketrent
0
67
Voice of the Leaders
jaketrent
0
66
Other Decks in Programming
See All in Programming
AI駆動で0→1をやって見えた光と伸びしろ
passion0102
1
880
Webサーバーサイド言語としてのRustについて
kouyuume
1
5k
オンデバイスAIとXcode
ryodeveloper
0
250
What's new in Spring Modulith?
olivergierke
1
170
Domain-centric? Why Hexagonal, Onion, and Clean Architecture Are Answers to the Wrong Question
olivergierke
3
980
Migration to Signals, Resource API, and NgRx Signal Store
manfredsteyer
PRO
0
130
三者三様 宣言的UI
kkagurazaka
0
280
チームの境界をブチ抜いていけ
tokai235
0
230
Things You Thought You Didn’t Need To Care About That Have a Big Impact On Your Job
hollycummins
0
260
Devoxx BE - Local Development in the AI Era
kdubois
0
150
他言語経験者が Golangci-lint を最初のコーディングメンターにした話 / How Golangci-lint Became My First Coding Mentor: A Story from a Polyglot Programmer
uma31
0
450
コードとあなたと私の距離 / The Distance Between Code, You, and I
hiro_y
0
200
Featured
See All Featured
Embracing the Ebb and Flow
colly
88
4.9k
Why You Should Never Use an ORM
jnunemaker
PRO
59
9.6k
Performance Is Good for Brains [We Love Speed 2024]
tammyeverts
12
1.2k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
127
54k
Statistics for Hackers
jakevdp
799
220k
[RailsConf 2023 Opening Keynote] The Magic of Rails
eileencodes
31
9.7k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
48
9.7k
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
PRO
190
55k
Java REST API Framework Comparison - PWX 2021
mraible
34
8.9k
The Language of Interfaces
destraynor
162
25k
Dealing with People You Can't Stand - Big Design 2015
cassininazir
367
27k
Navigating Team Friction
lara
190
15k
Transcript
JAVASCRIPT ERROR HANDLING FROM A TALK BY @XJAMUNDX AT #MWRC
TRY/CATCH • Use for JSON.parse • Don’t use like a
Java programmer
DON’T THROW • Only as a last resort • Nothing
else you can do
THROW - TJ FONTAINE • throw for programmer errors (eg,
missing required parameter) • https://us- east.manta.joyent.com/ dap/public/drop/er2.htm
ALWAYS USE ERROR OBJECTS • Not simply strings • Errors
contains stack traces • Will provide debug value
CREATE CUSTOM ERRORS • Extend Error - still of type
Error • New, specific type • Can attach other helpful properties (eg, data associated at time of error) • Other standard properties in Appendix: https://us- east.manta.joyent.com/dap/public/drop/er2.htm
CREATE CUSTOM ERRORS (2) ! function SpecialError(message, specialInfo) { Error.captureStackTrace(this,
arguments.callee) this.message = message this.name = ‘SpecialError' this.specialInfo = specialInfo } ! SpecialError.prototype = Object.create(Error.prototype)
CALLBACK W/ ERROR • Common pattern in Node • If
action creates error, pass as first parameter in callback
CALLBACK W/ ERROR (2) function doManyThings(done) { doAsync(function (err, data)
{ if (err) return done(err) // … done(null, data) }) }
NAME ANONYMOUS FUNCTIONS • Provides name in stack trace
NAME ANONYMOUS FUNCTIONS (2) doSomethingWithCallback(function veryCallback() { // if I
throw an error, stack trace <3 })
DOMAINS AREN’T COOL • core team is not pushing the
concept • https:// nodefirm.hackpad.com/ Node-Error-Handling- Summit-uXFi4FUg8Td
MAKE ERRORS TO CLIENTS CONSISTENT • Pass all errors through
a common error serializer • Client can also handle consistently
MAKE ERRORS TO CLIENTS CONSISTENT (2) res.json(400, formatError(err))
USE EXPRESS DEFAULT ERROR HANDLER • Good catch-all • Avoid
potential infinite loop bug in Express
USE EXPRESS DEFAULT ERROR HANDLER (2) app.use(function (err, req, res,
next) { res.json(500, formatError(err)) })
ON(‘UNCAUGHTEXCEPTION’) SHOULD ALWAYS EXIT • Call process.exit() • Otherwise, stuff
hangs • Long-running process might never complete for client; wait for timeout • Resources can be leaked (eg, db connections)
ON(‘UNCAUGHTEXCEPTION’) SHOULD ALWAYS EXIT (2) process.on('uncaughtException', function(err) { hurryAndWriteYourWill(err) process.exit()
});
RESOURCES • MWRC SLIDES FROM @XJAMUNDX HTTPS://CLOUDUP.COM/IHRJZBVDIFZ ! •
CORE TEAM NOTES HTTPS://NODEFIRM.HACKPAD.COM/NODE-ERROR-HANDLING-SUMMIT-UXFI4FUG8TD ! • TJ FONTAINE ERROR HANDLING HTTPS://US-EAST.MANTA.JOYENT.COM/DAP/PUBLIC/DROP/ER2.HTM
https://speakerdeck.com/jaketrent/javascript-error-handling