Avoid file locks + overwrites by using a temp file for HTML templates (#1336)

* Avoid file locks + overwrites by using a temp file for HTML templates

This fixes #1331.

* refactor: Replace tempy with simple random number gen

* docs: Adding changeset

Co-authored-by: Ryan Christian <[email protected]>

Author: developit

.changeset/violet-dryers-smell.md

@@ -0,0 +1,5 @@
+---
+'preact-cli': patch
+---
+
+Temp files generated by `preact-cli` are now unique to a build, allowing for concurrent instances to run at the same time.

packages/cli/src/lib/webpack/render-html-plugin.js

@@ -45,7 +45,10 @@ module.exports = async function (config) {
 
 		// Unfortunately html-webpack-plugin expects a true file,
 		// so we'll create a temporary one.
-		const tmpDir = join(os.tmpdir(), 'preact-cli');
+		const tmpDir = join(
+			os.tmpdir(),
+			`preact-cli-${Math.floor(Math.random() * 100000)}`
+		);
 		if (!existsSync(tmpDir)) {
 			mkdirSync(tmpDir);
 		}