Let `cargo` handle building the UI, where possible.

This allows skipping the `target/ui` rebuild if the UI has not changed, which has otherwise been a bit of a source of drag on my development speed.

1 files changed, 42 insertions, 3 deletions

diff --git a/build.rs b/build.rs
index d506869..a61b2db 100644
--- a/build.rs
+++ b/build.rs
@@ -1,5 +1,44 @@
-// generated by `sqlx migrate build-script`
-fn main() {
+use std::{io, process::Command};
+
+fn main() -> Result<(), io::Error> {
     // trigger recompilation when a new migration is added
-    println!("cargo:rerun-if-changed=migrations");
+    println!("cargo::rerun-if-changed=migrations");
+
+    // rerun npm install whenever packages or npm config are changed
+    println!("cargo::rerun-if-changed=.npmrc");
+    println!("cargo::rerun-if-changed=package.json");
+    // `node_modules` and `package-lock.json` are always touched if `npm install`
+    // runs, leading to spurious rebuilds.
+    //
+    // See: <https://github.com/npm/cli/issues/7874>
+    // println!("cargo::rerun-if-changed=package-lock.json");
+    // println!("cargo::rerun-if-changed=node_modules");
+    let status = Command::new("npm").args(["install"]).status()?;
+    if !status.success() {
+        return Err(io::Error::other(format!(
+            "'npm install' exited with status {status:?}"
+        )));
+    }
+
+    // rerun `npm run build` whenever the UI changes.
+    //
+    // `node_modules` is always touched if `npm install` runs, leading to spurious
+    // rebuilds. (This duplicate is purely organizational; it reflects that the ui
+    // depends on node_modules.)
+    //
+    // See: <https://github.com/npm/cli/issues/7874>
+    // println!("cargo::rerun-if-changed=node_modules");
+    println!("cargo::rerun-if-changed=postcss.config.js");
+    println!("cargo::rerun-if-changed=svelte.config.js");
+    println!("cargo::rerun-if-changed=tailwind.config.js");
+    println!("cargo::rerun-if-changed=vite.config.js");
+    println!("cargo::rerun-if-changed=ui");
+    let status = Command::new("npm").args(["run", "build"]).status()?;
+    if !status.success() {
+        return Err(io::Error::other(format!(
+            "'npm run build' exited with status {status:?}"
+        )));
+    }
+
+    Ok(())
 }