Walking through the source code of an OSS Library(ESLint))

Walking through the source code of an OSS library(ESLint)
l4VNNFS+BWB4DSJQU'FTUJWBM0OMJOFz @kkeeth @kuwahara_jsri @kkeeth

While looking back on a day 💁

*`NBMFBEFOHJOFFSPSUFDIMFBE *WFDSFBUFEB13 QMFBTFSFWJFX me Team Member A 0,👍*`MMSFWJFXBOEGFFECBDLZPV me

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B, C … 0,👍*`MMSFWJFXBOEGFFECBDLZPV me

1MFBTFSBUFUIJTDBOEJEBUFTDPEF Recruitment Personnel *`NBTFSWBOUMFBEFSPGPGBDSPTTFBDI FOHJOFFSJOHHSPVQ me *`NBNFNCFSPGUIF#PBSE me

me 0,👍*`MMSFWJFXBOEGFFECBDLZPV *TUPQQFEXSJUJOHNPSFBOENPSFDPEF *GZPVPOMZSFBEDPEF DBUDIJOHVQXJUIOFX UFDIOPMPHJFTTVDIBTMJCSBSJFTBOEGSBNFXPSLTUFOET UPCFTVQFS fi DJBM4Pʜ *GFFMmy
technical skills have declined… Voice of my heart

me 0,👍*`MMSFWJFXBOEGFFECBDLZPV *TUPQQFEXSJUJOHNPSFBOENPSFDPEF *GZPVPOMZSFBEDPEF DBUDIJOHVQXJUIOFX UFDIOPMPHJFTTVDIBTMJCSBSJFTBOEGSBNFXPSLTUFOET UPCFTVQFS fi DJBM4Pʜ *GFFMmy
technical skills have declined… Voice of my heart I've got to do something ʘ(^o^)ʗ

I feel like I could learn more from reading codes
😆

About me

Published 📙

OQNKTDPNdLLFFUI

🙇 Sorry … 🙇 This slide is written in English.
However, I am still learning English, and there may be some inappropriate expressions. Plz feedback for me called “Masakari” about my talk!!

Let’s start 😆

Then, let's read the source code of ESLint!

*NBHFCZIUUQTFTMJOUPSH

Basically, we start from the module written in the main
of package.json💁

This is the main one. This is a so-called controller
💁

This is the module that actually does the work 💁

As the name implies, it is a helper or preparation
for testing. It includes many things 💁

This one is just like the name. This is a
collection of processes that handle source code. 💁

Next, let’s look at “bin” dir.

Only 3 helper functions and an executable function here💁

Next, let’s look at “lib/cli.js” fi le.

“cli.js” depends on “ESLint” module “ESLint” module depends on “CLIEngine”
module

I found out later that...

There exists a dependency map💁 *NBHFCZIUUQTHJUIVCDPNFTMJOUFTMJOUCMPCNBJOEPDTTSDEFWFMPQFSHVJEFBSDIJUFDUVSFEFQFOEFODZTWH

Knowledge 1: Overall design

Unified format for writing each module📝

Uni fi ed format for writing each module

util objects rich in methods📝

w /PEFKTlVUJMzPCKFDU w MJCSVMFTVUJMTBTUVUJMT w MJCTIBSFETUSJOHVUJMT w MJCTIBSFETBTUVUJMT NFUIPET SFHHFYQBUUFSOT
w MJCTPVSDFDPEFUPLFOTUPSFVUJMT the number of using methods

Knowledge 2: Node.js’s “util” module is useful

w VUJMJOTQFDU w VUJMGPSNBU w VUJMJOIFSJUT w VUJMMQSPNJTJGZ ˡ8IBUTVSQSJTFENFXBTUIJT Methods
used by ESLint

*NBHFCZIUUQTOPEFKTPSHBQJVUJMIUNM

Knowledge 3: Generator functions in JavaScript

Do you understand the following code?💁

Let's take a look at some sample codes💁

more detail, show MDN👉

An afterthought

An afterthought w /PUXSJUUFOJOUZQFTDSJQU UZQFEF fi OJUJPOTBSFXSJUUFO w "OZXBZ
UIFEPDVNFOUBUJPOJTFYUFOTJWF w +4%PDJTXFMMEPDVNFOUFE BTJTNE w %PDVNFOUBUJPOJTVTJOH&MFWFOUZKT UZ w 5PPMTGPS44( w %PDVNFOUBUJPOBQQJTFBTJFSUPWJFXUIBOUIFP ff i DJBMTJUF w 5IFSFBSFBMTPDPODFQUTPGMBZPVUBOEDPNQPOFOUT

Thoughts💁

Thoughts w 8FEPOUIBWFUPVOEFSTUBOEJUUPUBMZ👍 w %FTJHOJOHGBNPVTMJCSBSJFTJTBHSFBUMFBSOJOHFYQFSJFODF👍 w 8FDBOJNQSPWFNZTLJMMTGPSTVSF👍 w *GZPV fi
OEJUEJ ff i DVMU ZPVDBOSFBEJUXJUITPNFPOFFMTF👍 w *GZPVIBWFUSPVCMF JU`THPPEUPSFBEGSPNUIFUFTUDPEF👍

Walking through the source code of an OSS Libra...

Walking through the source code of an OSS Library(ESLint))

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