From 32bde06a1685123ee811492d346695b404b4e117 Mon Sep 17 00:00:00 2001
From: Paul Hinze <phinze@phinze.com>
Date: Wed, 18 Oct 2023 21:16:52 -0500
Subject: [PATCH] nix: add lefthook

Allows pre-commit linters to run in Nix development environments.

Lefthook needs to be able to invoke `node` directly so explicitly add
`nodejs` to dependencies as well. This is probably worthwhile for asset
generation stuff anyways.
---
 NIX.md    | 10 ++++++++++
 flake.nix |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/NIX.md b/NIX.md
index d264e10c6..f5e1e7ac1 100644
--- a/NIX.md
+++ b/NIX.md
@@ -87,3 +87,13 @@ $ bin/rails test:system
 The Selenium tests are run by having Nix install Chromium and ChromeDriver and
 set a `SELENIUM_CHROME_BINARY` environment variable to point Selenium at
 Chromium in `test/application_system_test_case.rb`.
+
+## Precommit Hooks
+ 
+Precommit hooks are managed by `lefthook`, which is automatically installed
+into the Nix development shell. Install the hooks to get them to run on every
+commit:
+
+```shell-session
+$ lefthook install
+```
diff --git a/flake.nix b/flake.nix
index b0d775996..07566f966 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,6 +26,7 @@
           mkShell {
             buildInputs = [
               ruby
+              nodejs
               yarn
               foreman
 
@@ -38,6 +39,9 @@
               # for selenium tests
               chromium
               chromedriver
+
+              # for linters and git hooks
+              lefthook
             ];
 
             # Keep gems installed in a subdirectory