Problem

When using code generators like paraglide-js (i18n), graphql-codegen, or prisma, wrangler's custom build watch triggers infinite rebuild loops because generated files are detected as changes.

Current Behavior

[build]
command = "pnpm build"
watch_dir = "src"

What happens:

1. Build generates files in src/lib/paraglide/
2. Wrangler detects file changes in watch_dir
3. Triggers rebuild
4. Build generates files again
5. Infinite loop 🔄

Additionally:

• .gitignore patterns are not respected by watch
• No way to exclude subdirectories from watch

Proposed Solution

Option 1: Add watch_ignore parameter

[build]
command = "pnpm build"
watch_dir = "src"
watch_ignore = ["src/lib/paraglide/**", "**/.svelte-kit/**"]

Option 2: Automatically respect .gitignore

Wrangler should automatically exclude paths listed in .gitignore from the watch mechanism.

Use Cases

This affects any project using code generators:

• i18n: paraglide-js, typesafe-i18n
• GraphQL: graphql-codegen
• ORM: prisma client generate
• Type generation: openapi-typescript
• Build artifacts: .svelte-kit, .next, etc.

Current Workaround

Users must manually run build before dev:

pnpm build && pnpm wrangler dev --port 8788

This removes the benefit of automatic rebuilds on file changes.

Related Issues

• Prevent custom builds from executing concurrenctly #10944 - Prevent custom builds from executing concurrently

Environment

• wrangler: 4.42.2
• Framework: SvelteKit
• Adapter: @sveltejs/adapter-cloudflare