Fix: Netlify Deploy Fail With Bun SyntaxError

Hey guys! Ever stumbled upon a cryptic error message that just makes you scratch your head? Well, I've been wrestling with one of those lately, and I thought I'd share my journey (and hopefully a solution!) with you all. The culprit? A Netlify deployment failing with a SyntaxError: Unexpected token ':' during the “Edge Functions bundling” phase when using Bun. Sounds like a mouthful, right? Let's break it down and see what's going on.

Understanding the SyntaxError in Edge Functions Bundling

So, the main issue here is the SyntaxError: Unexpected token ':'. This error pops up during the Edge Functions bundling process on Netlify. For those new to the term, Edge Functions are pieces of code that run on Netlify's edge network, bringing your functions closer to your users for faster performance. The bundling process is where Netlify packages up these functions for deployment. This particular error usually points to a problem with the syntax of your code, specifically an unexpected colon (:).

In the context of Netlify and Qwik, this error often originates from the Edge Functions manifest validation process. Netlify uses a tool called @netlify/edge-bundler, which relies on ajv (Another JSON Schema Validator) to ensure your Edge Functions manifest (a file that describes your functions) is correctly formatted. If there's a syntax hiccup in this manifest, ajv throws the SyntaxError. Think of it as a strict grammar checker for your deployment files! To really drive this home, this error indicates that the Netlify Edge Functions are not bundling correctly due to a syntax issue, likely within a configuration or manifest file. Let's dive deeper to provide you with a solid understanding and practical steps to resolve this pesky problem. To effectively tackle this, we will explore the common causes, diagnostic approaches, and solutions. This error often arises due to incompatibilities between the project's generated output and Netlify's bundler expectations, specifically during the manifest validation phase.

Reproducing the Bug: A Step-by-Step Guide

To effectively debug this, let's outline the steps to reproduce this bug. This will help you (and me!) pinpoint the exact moment things go south. In the following steps, we try to reproduce the issue:

1. Set up a Qwik project with the netlify-edge adapter: This is the foundation. We need a Qwik project configured to use Netlify's Edge Functions.
2. Use bun as your package manager and script runner: bun is known for its speed, but sometimes it can reveal compatibility issues that other package managers might mask.
3. Configure for Netlify deployment: This involves setting up your netlify.toml file and any other Netlify-specific configurations.
4. Run the deployment command (e.g., bun run deploy): This is where the magic (or, in this case, the error) happens.
5. Observe the build failing on Netlify: If you're facing this issue, the build process will halt during the bundling phase, throwing that infamous SyntaxError.

If you follow these steps, and the build process fails on Netlify with the SyntaxError we're talking about, then you've successfully reproduced the issue! This is a crucial first step because now you have a consistent environment to test solutions.

Deciphering the Error Logs

Error logs, my friends, are like detective clues! They might seem intimidating at first, but they hold valuable information. Let's dissect a typical error log from a failed Netlify build:

Internal error during "Edge Functions bundling"
────────────────────────────────────────────────────────────────

  Error message
  SyntaxError: Unexpected token ':'

  Error location
  During Edge Functions bundling
      at new Function (<anonymous>)
      at Ajv.compileSchema (/home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/node_modules/@netlify/edge-bundler/node_modules/ajv/dist/compile/index.js:89:30)
      at Ajv._compileSchemaEnv (/home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/node_modules/@netlify/edge-bundler/node_modules/ajv/dist/core.js:473:37)
      at Ajv.compile (/home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/node_modules/@netlify/edge-bundler/node_modules/ajv/dist/core.js:160:38)
      at initializeValidator (file:///home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/node_modules/@netlify/edge-bundler/dist/node/validation/manifest/index.js:17:33)
      at validateManifest (file:///home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/node_modules/@netlify/edge-bundler/dist/node/validation/manifest/index.js:24:22)
      at validateEdgeFunctionsManifest (file:///home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/lib/plugins_core/edge_functions/validate_manifest/validate_edge_functions_manifest.js:5:9)
      at coreStep (file:///home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/lib/plugins_core/edge_functions/index.js:48:15)
      at async fireCoreStep (file:///home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/lib/steps/core_step.js:9:98)
      at async tFireStep (file:///home/tom/Documents/Dental_Qwik/node_modules/@netlify/build/lib/time/main.js:18:63)

  Resolved config
  build:
    command: npm run build
    commandOrigin: config
    publish: /home/tom/Documents/Dental_Qwik/dist
    publishOrigin: config
  headers:
    - for: /assets/*
      values:
        Cache-Control: public, max-age=31536000, s-maxage=31536000, immutable
    - for: /build/*
      values:
        Cache-Control: public, max-age=31536000, s-maxage=31536000, immutable
Waiting for the debugger to disconnect...
error: script "deploy" exited with code 4

Let's break down the key parts:

• **`Internal error during