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
ヤバいESLint/TSLintルール作っちゃったかもしれない
Search
boiyama
April 24, 2018
Programming
0
1.5k
ヤバいESLint/TSLintルール作っちゃったかもしれない
Roppongi.js #2 での発表資料です。
https://roppongi-js.connpass.com/event/82998/
boiyama
April 24, 2018
Tweet
Share
More Decks by boiyama
See All by boiyama
Reproのビジネスサイドを支えるJS
boiyama
0
170
バックオフィスに行ったソフトウェアエンジニアの業務効率化事例
boiyama
1
260
2018年、IE6対応サイトを作る
boiyama
4
980
チームをCQRS
boiyama
1
1.5k
フロントエンドのサーバーレス SSR編
boiyama
0
700
Serverless for Front-end Server-Side Rendering
boiyama
1
110
Learning Elm in JS
boiyama
1
550
JSでElmを学ぶ
boiyama
0
97
フロントエンドのサーバーレス SPA編
boiyama
1
1.1k
Other Decks in Programming
See All in Programming
Things You Thought You Didn’t Need To Care About That Have a Big Impact On Your Job
hollycummins
0
210
Web Components で実現する Hotwire とフロントエンドフレームワークの橋渡し / Bridging with Web Components
da1chi
3
2k
『毎日の移動』を支えるGoバックエンド内製開発
yutautsugi
2
230
バッチ処理を「状態の記録」から「事実の記録」へ
panda728
PRO
0
140
スマホから Youtube Shortsを見られないようにする
lemolatoon
27
29k
SpecKitでどこまでできる? コストはどれくらい?
leveragestech
0
680
CSC509 Lecture 05
javiergs
PRO
0
300
10年もののAPIサーバーにおけるCI/CDの改善の奮闘
mbook
0
810
iOSエンジニア向けの英語学習アプリを作る!
yukawashouhei
0
190
CSC305 Lecture 03
javiergs
PRO
0
240
GraphQL×Railsアプリのデータベース負荷分散 - 月間3,000万人利用サービスを無停止で
koxya
1
1.2k
Conquering Massive Traffic Spikes in Ruby Applications with Pitchfork
riseshia
0
160
Featured
See All Featured
Thoughts on Productivity
jonyablonski
70
4.9k
Distributed Sagas: A Protocol for Coordinating Microservices
caitiem20
333
22k
Performance Is Good for Brains [We Love Speed 2024]
tammyeverts
12
1.2k
Helping Users Find Their Own Way: Creating Modern Search Experiences
danielanewman
30
2.9k
Building Adaptive Systems
keathley
43
2.8k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
234
17k
Intergalactic Javascript Robots from Outer Space
tanoku
273
27k
Building an army of robots
kneath
306
46k
The Cult of Friendly URLs
andyhume
79
6.6k
Learning to Love Humans: Emotional Interface Design
aarron
274
41k
A Tale of Four Properties
chriscoyier
160
23k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
23
1.5k
Transcript
Ϡό ͍ E S L i n t / T
S L i n t ϧ ʔϧ ࡞ ͬ ͪ Ό ͬ ͨ ͔ ͠ Ε ͳ ͍ 2 0 1 8 . 4 . 2 4 R o p p o n g i . j s # 2
P ro f i l e • ϑϩϯτΤϯυΤϯδχΞ at PERSOL
• GitHub: boiyaa Twitter: boiyaaaaaa
Ͳ Μ ͳ ϧ ʔϧ ͔ return จΛېࢭͯ͠Έͨ eslint-plugin-no-return tslint-no-return
ݩʑଞͷؔܕݴޠνοΫͳจ๏Λਅࣅ͔ͨͬͨ ˍؔͷॻ͖ํΛἧ͔͑ͨͬͨతͳಈػɻ
// Error function foo(bar) { const baz = bar **
2; return baz; } // Error const foo = function (bar) { const baz = bar ** 2; return baz; }; // Error const foo = bar => { const baz = bar ** 2; return baz; }; // OK const foo = bar => bar ** 2;
Λฦؔ͢Λॻ࣌͘ʹɺΞϩʔؔͷ؆ܿจମ͔͠ ͑ͳ͘ͳΔ͚͔ͩͱࢥ͚ͬͨͲ จ͕ॻ͚ͳ͍؆ܿจମʹΑͬͯɺ৭ʑͳॻ͖ํΛ౷ҰͰ ͖ͨΓɺ Lint ϧʔϧΛγϯϓϧʹͰ͖ͨΓ͢Δ͜ͱʹؾ ͍ͮͨɻ
݅ͷॻ͖ํΛ౷ҰͰ͖ͯɺ ϧʔϧΛݮΒͤͨɻ
const foo = bar => { if (bar == "baz")
{ return "qux"; } return "quux"; }; const foo = bar => { switch (bar) { case "baz": { return "qux"; } default: { return "quux"; } } }; // ! const foo = bar => (bar == "baz" ? "qux" : "quux");
if switch ESLint ϧʔϧଟ͍ͷͰ͑ͳ͍ͳΒ͖ͬ͢ Γ͍͍ͯ͠ͱࢥ͏ɻ Ͱࡾ߲ԋࢉࢠ൱ఆ͕݁ߏ͍Δ͠ೖΕࢠϠό͍ɻ Ramda ΛͬͯΈΔͱ͔
const foo = bar => (bar == "baz" ? "qux"
: "quux"); // ! const foo = ifElse(equals("baz"), always("qux"), always("quux"));
const foo = (bar, baz) => { if (bar <
baz) { return "qux"; } else if (bar > baz) { return "quux"; } return "corge"; }; // ! const foo = cond([ [R.lt(R.__, R.__), R.always("qux")], [R.gt(R.__, R.__), R.always("quux")], [T, always("corge")] ]);
const foo = bar => { switch (bar) { case
"baz": { return "qux"; } case "quux": { return "corge"; } default: { return "grault"; } } }; // ! const foo = cond([ [equals("baz"), always("qux")], [equals("quux"), always("corge")], [T, always("grault")] ]);
ϧʔϓͷॻ͖ํΛ౷ҰͰ͖ͨɻ
const foo = bar => { const baz = [];
for (let i = 0; i < bar.length; i++) { baz.push(bar[i] ** 2); } return baz; }; // ! const foo = bar => bar.map(baz => baz ** 2);
const foo = count => { const baz = [];
for (let i = 0; i < count; i++) { baz.push(i ** 2); } return baz; }; // ! const foo = (count, baz, i) => i < count ? foo(count, [].concat(baz, [i ** 2]), i + 1) : baz;
for ͱ͔ while ͱ͔ॻ͚ͳ͍ͱɺྻ͍͍ͱͯ͠ɺ ؆ܿจମʴࡾ߲ԋࢉࢠͷ࠶ؼؔಡΈʹ͍͘ɻ ͜Ε Ramda Ͱॻ͍ͯΈΔɻ
const foo = bar => { const baz = [];
for (let i = 0; i < bar.length; i++) { baz.push(bar[i] ** 2); } return baz; }; // ! const foo = bar => bar.map(baz => baz ** 2); // ! const foo = bar => map(baz => baz ** 2, bar);
const foo = count => { const baz = [];
for (let i = 0; i < count; i++) { baz.push(i ** 2); } return baz; }; // ! const foo = (count, baz, i) => i < count ? foo(count, [].concat(baz, [i ** 2]), i + 1) : baz; // ! const foo = count => times(i => i ** 2, count);
มɾఆΛఆٛͰ͖ͳ͘ͳͬͨ
const foo = bar => { const baz = bar
** 2; return baz + baz; }; // ! const foo = bar => bar ** 2 + bar ** 2; // ! let ࣜ෩Ξϓϩʔν const foo = bar => (baz => baz + baz)(bar ** 2);
const foo = bar => { const baz = bar
** 2; const qux = baz ** 2; const quux = qux ** 2; return baz + qux + quux; }; // ! let ࣜ෩ΞϓϩʔνϠό͍ const foo = bar => (baz => ((baz, qux) => ((baz, qux, quux) => baz + qux + quux)(baz, qux, qux ** 2))( baz, baz ** 2 ))(bar ** 2);
// ͜ΜͳؔΛ࡞Δ const letin = (initialValue, funcs) => funcs .reduce(
(previousValue, func) => [ ...previousValue, func.apply(null, previousValue) ], initialValue ) .pop();
const foo = bar => { const baz = bar
** 2; const qux = baz ** 2; const quux = qux ** 2; return baz + qux + quux; }; // ! const foo = bar => letin( [bar], [ bar => bar * bar, (bar, baz) => baz * baz, (bar, baz, qux) => qux * qux, (bar, baz, qux, quux) => baz + qux + quux ] );
return Ҏ֎ͷจ͔͚ΔͷͰɺ Λฦ͞ͳ͍ؔͳΒͳΜͰ͋Γ
function foo(bar) { bar.baz = "qux"; bar.quux.push("corge"); } const foo
= function (callback) { callback(); }; const foo = () => { throw new Error("bar"); }; function* foo() { yield "bar"; }
· ͱ Ί • ESLint/TSLint ͷϧʔϧઃఆ͕γϯϓϧʹͳΔ • ͪΐͬͱίʔυॻ͖ʹ͍͘ • গͳ͍ϧʔϧͰ৭ʑͳॻ͖ํ੍͕ݶ͞ΕΔ͜ͱࣗମ
͍͍͔ͳͱࢥ͍ͬͯΔ
Έ͍ͨͳ