From 3591c91a8a9475d01485b08b72aa4780205d3add Mon Sep 17 00:00:00 2001
From: Isaac Levy <isaac.r.levy@gmail.com>
Date: Thu, 24 Oct 2024 18:29:33 -0400
Subject: [PATCH] Speed up eslint with --cache
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And also align eslint ignored files with how eslint is
automatically run.

This ensures that all contributors run lint on the same
set of files. Prior to this change, eslint covers ts files
outside ui with its default rules, meaning contributors might
commit code with fresh eslint errors that only show up when
eslint is run bare, or if an eslint extension is installed in
a code editor.

Because this commit adds a global ignore pattern on all folders
by default, the bare `eslint` command run no longer takes
additional time over `eslint ui`. And the --cache flag means
lint will usually be dramatically faster than before.

One-off eslint checks on files in ignored directories can still be
performed with: `eslint <path to file>`

Pre-commit run of eslint
```
$ hyperfine -w 3 -N  'node_modules/.bin/eslint ui'
  Time (mean ± σ):      2.405 s ±  0.018 s    [User: 4.728 s, System: 0.316 s]
  Range (min … max):    2.374 s …  2.444 s    10 runs
```

Post-commit run of eslint, without the ui argument.
(faster because of the more efficient global ignore patterns)

```
$ hyperfine -w 3 -N  'node_modules/.bin/eslint'
  Time (mean ± σ):      2.203 s ±  0.011 s    [User: 4.338 s, System: 0.296 s]
  Range (min … max):    2.188 s …  2.225 s    10 runs
```

Post-commit example of lint script if repeatedly run.
This is much faster, thanks to --cache.

```
$ hyperfine -w 3 -N  'node --run lint'
Benchmark 1: node --run lint
  Time (mean ± σ):     487.3 ms ±   2.4 ms    [User: 606.9 ms, System: 85.5 ms]
  Range (min … max):   483.7 ms … 491.0 ms    10 runs
```

----

I've also added --cache to prettier format scripts.
Note that while prettier automatically manages the cache for most
tooling updates, it does not clear cache on prettier plugin updates
(which we aren't currently using). Nonetheless, to future proof our
prettier cache, I'm purposely leaving --cache off the pre-commit hook,
which ensures the prettier cache will be often cleared. The cache is
still useful when repeatedly running format or when using watch-format.

```
$ hyperfine -w 3 -N  'node --run format'
  Time (mean ± σ):      4.656 s ±  0.066 s    [User: 7.785 s, System: 0.896 s]
  Range (min … max):    4.594 s …  4.808 s    10 runs
```

Post-commit example of prettier under repeated use, now much faster
thanks to --cache
```
$ hyperfine -w 3 -N  'node --run format'
  Time (mean ± σ):      1.777 s ±  0.022 s    [User: 1.879 s, System: 0.646 s]
  Range (min … max):    1.751 s …  1.814 s    10 runs
```
---
 .gitignore        | 3 +++
 eslint.config.mjs | 2 +-
 package.json      | 8 ++++----
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 1bfbde60f670..c918ace59412 100644
--- a/.gitignore
+++ b/.gitignore
@@ -51,3 +51,6 @@ RUNNING_PID
 # Docker-compose / docker sbt
 /docker-compose.yml
 /?
+
+# eslint cache
+/.eslintcache
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 00c911c7c8d0..0152bb2920b1 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -2,9 +2,9 @@ import typescriptEslint from '@typescript-eslint/eslint-plugin';
 import tsParser from '@typescript-eslint/parser';
 
 export default [
+  { ignores: ['*', '!ui/', '!bin/', '**/dist/'] },
   {
     files: ['**/*.ts'],
-    ignores: ['**/dist/**', '**/node_modules/**', '**/public/**'],
     plugins: { '@typescript-eslint': typescriptEslint },
     languageOptions: { parser: tsParser, ecmaVersion: 5, sourceType: 'module' },
     rules: {
diff --git a/package.json b/package.json
index 547e6a5a4ad0..ea51ab3d0667 100644
--- a/package.json
+++ b/package.json
@@ -41,12 +41,12 @@
     "typescript": "^5.6.2"
   },
   "scripts": {
-    "format": "prettier --write --log-level warn .",
-    "check-format": "prettier --check --log-level warn .",
-    "watch-format": "onchange \"**/*\" -- prettier --write --log-level warn {{changed}}",
+    "format": "prettier --cache --write --log-level warn .",
+    "check-format": "prettier --cache --check --log-level warn .",
+    "watch-format": "onchange \"**/*\" -- prettier --cache --write --log-level warn {{changed}}",
     "add-hooks": "git config --add core.hooksPath bin/git-hooks",
     "remove-hooks": "git config --unset core.hooksPath bin/git-hooks",
-    "lint": "eslint ui",
+    "lint": "eslint --cache",
     "journal": "journalctl --user -fu lila -o cat",
     "metals": "tail -F .metals/metals.log | stdbuf -oL cut -c 21- | rg -v '(notification for request|handleCancellation)'",
     "serverlog": "pnpm journal & pnpm metals",