🐛 BUG: env.process.NODE_ENV returns 'undefined' in Cloudflare Workers

[MrChrisRodriguez]

What versions & operating system are you using?

Wrangler 4.22.0, Node v20.19.2

Please provide a link to a minimal reproduction

https://github.com/Confiador/cf-worker-node-env

Describe the Bug

Environment:

• Runtime: Cloudflare Workers (via Wrangler) run locally
• Development server: wrangler dev --ip=127.0.0.1 --env development --port 1234

Issue Description:
The NODE_ENV environment variable cannot be accessed using standard JavaScript property access methods (process.env.NODE_ENV or process.env['NODE_ENV']), despite being present in the environment and accessible through other means.

Expected Behavior:
process.env.NODE_ENV should return 'development'

Actual Behavior:
process.env.NODE_ENV returns the string undefined.

Evidence:

// All of these show NODE_ENV exists:
console.log(process.env); // Shows: { NODE_ENV: 'development', ... }
Object.keys(process.env); // Includes 'NODE_ENV'
'NODE_ENV' in process.env; // Returns true
Object.getOwnPropertyDescriptor(process.env, 'NODE_ENV'); // Shows { value: 'development', ... }

// But standard access fails:
process.env.NODE_ENV; // Returns undefined
process.env['NODE_ENV']; // Returns undefined

// Only Reflect.get() works:
Reflect.get(process.env, 'NODE_ENV'); // Returns 'development'

Key Details:

• Other environment variables work correctly with all access methods
• The issue is specific to NODE_ENV
• Property descriptor shows the value exists and is accessible
• Reflect.get() successfully retrieves the correct value

Root Cause:
Appears to be a bug in Cloudflare Workers' process.env Proxy implementation where the get trap has faulty handling specifically for the NODE_ENV property.

Workaround:
Use Reflect.get(process.env, 'NODE_ENV') instead of direct property access.

Please provide any relevant error logs

(base) cf-worker-node-env % wrangler dev --ip=127.0.0.1 --env development --port 1234

 ⛅️ wrangler 4.22.0
───────────────────
Your Worker has access to the following bindings:
Binding                           Resource                  Mode
env.NODE_ENV ("development")      Environment Variable      local

╭──────────────────────────────────────────────────────────────────────╮
│  [b] open a browser [d] open devtools [c] clear console [x] to exit  │
╰──────────────────────────────────────────────────────────────────────╯
⎔ Starting local server...
[wrangler:info] Ready on http://127.0.0.1:1234

============================================================
🐛 CLOUDFLARE WORKERS NODE_ENV BUG REPRODUCTION

📋 SECTION 1: Verify NODE_ENV exists in environment
Full process.env object: { NODE_ENV: 'development' }
Keys in process.env: [ 'NODE_ENV' ]
NODE_ENV in process.env keys? true

🔍 SECTION 2: Property existence checks
'NODE_ENV' in process.env: true
process.env.hasOwnProperty('NODE_ENV'): true
Object.getOwnPropertyNames includes NODE_ENV: true

🔬 SECTION 3: Property descriptor analysis
NODE_ENV property descriptor: {
value: 'development',
writable: true,
enumerable: true,
configurable: true
}

• value: development
• writable: true
• enumerable: true
• configurable: true

❌ SECTION 4: BUG DEMONSTRATION - Standard access fails
process.env.NODE_ENV: undefined
process.env['NODE_ENV']: undefined
Expected: 'development' (or current NODE_ENV value)
Actual: undefined

✅ SECTION 5: WORKAROUND - Reflect.get works
Reflect.get(process.env, 'NODE_ENV'): development
This correctly returns the NODE_ENV value!

🆚 SECTION 6: Comparison with other env vars

🔧 SECTION 7: Additional debugging info
typeof process.env: object
process.env constructor: Object
Is process.env a Proxy? true

============================================================
🏁 END OF BUG REPRODUCTION

[wrangler:info] GET / 200 OK (8ms)

[vicb]

I think this is related to:

• 🐛 BUG: process.env.NODE_ENV is not set to production by default #7886
• fix(wrangler): handling of process.env.NODE_ENV in bundling mode #7974

My understanding is that wrangler adds an define for process.env.NODE_ENV meaning that this global would be replaced at build time.

Notes:

• From the links at the start of this comment, it looks like to value that we set is not necessarily the correct one,
• When process is imported (i.e. import process from "node:process";) then ESBuild will not replace the value (not a global any more).

So I think there are a few things to fix here:

1. The value of the ESBuild define
2. We should probably make sure that the runtime value of process.env.NODE_ENV matches what ESBuild uses.

• it might mean we have to inject NODE_ENV
• what happens when process.env.NODE_ENV="build" at build time but NODE_ENV="wrangler" in the wrangler env vars?

4. Add docs - I don't think the behavior is documented anywhere.