fix(util): detect Cloudflare Workers in shouldUseGlobalFetchAndWebSocket

[Muhammad-Bin-Ali]

Closes #11455

Problem

shouldUseGlobalFetchAndWebSocket() returns false on Cloudflare Workers with nodejs_compat, causing client.login() to hang indefinitely.

Workers with nodejs_compat polyfills globalThis.process including process.versions.node. The function sees process, checks for deno/bun in versions, finds neither, and returns false (defaulting to the ws npm package (TCP sockets)). Workers doesn't support TCP sockets, so the gateway connection hangs forever with no error.

Fix

Check for globalThis.WebSocketPair (a Workers-only global) before the Deno/Bun branch. This is the same detection approach already used by getUserAgentAppendix() in the same file.

Workers natively supports both globalThis.WebSocket and globalThis.fetch, so returning true is correct for both consumers (@discordjs/ws and @discordjs/rest).

Changes

• packages/util/src/functions/runtime.ts — added WebSocketPair check (8 lines)
• packages/util/__tests__/runtime.test.ts — new file, 6 tests covering every branch

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2 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
discord-js	Ignored		Mar 19, 2026 3:18pm
discord-js-guide	Ignored		Mar 19, 2026 3:18pm

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📝 Walkthrough

Walkthrough

This PR enhances the shouldUseGlobalFetchAndWebSocket runtime detection function by adding an early check for WebSocketPair on globalThis to detect Cloudflare Workers environments, and introduces comprehensive test coverage for the function across multiple runtime scenarios (browser, Node.js, Deno, Bun, and Cloudflare Workers).

Changes

Cohort / File(s)	Summary
Test Coverage packages/util/__tests__/runtime.test.ts	Added 45 lines of test cases validating shouldUseGlobalFetchAndWebSocket behavior across six runtime environments: browser with/without fetch/WebSocket, Cloudflare Workers with node compatibility, Node.js, Deno, and Bun.
Runtime Detection Logic packages/util/src/functions/runtime.ts	Added early return condition checking for WebSocketPair on globalThis to detect Cloudflare Workers before evaluating process versions.

Possibly related issues

• shouldUseGlobalFetchAndWebSocket() returns false on Cloudflare Workers with nodejs_compat #11455: The PR implements the proposed fix for detecting Cloudflare Workers with nodejs_compat by checking for globalThis.WebSocketPair.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically identifies the main fix: detecting Cloudflare Workers in the shouldUseGlobalFetchAndWebSocket function, which matches the primary change in the changeset.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Description check	✅ Passed	The PR description clearly explains the problem, the fix, and the specific changes made, directly aligned with the changeset.

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📝 Coding Plan

• Generate coding plan for human review comments

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Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/util/__tests__/runtime.test.ts`:
- Around line 16-23: The test mutates globals with delete which
vi.unstubAllGlobals() won't restore; update the test "GIVEN browser env without
fetch or WebSocket THEN returns false" to avoid direct deletion by using
vi.stubGlobal('fetch', undefined) and vi.stubGlobal('WebSocket', undefined) (or
alternatively capture original descriptors for globalThis.fetch and
globalThis.WebSocket and restore them in a try/finally), then assert
shouldUseGlobalFetchAndWebSocket() returns false and ensure cleanup/un-stubbing
occurs so other tests are not affected.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 7fe9722e-9dbb-4d35-8416-f382e808b8f8

📥 Commits

Reviewing files that changed from the base of the PR and between 2a06721 and 40d5344.

📒 Files selected for processing (2)

• packages/util/__tests__/runtime.test.ts
• packages/util/src/functions/runtime.ts

📜 Review details

🔇 Additional comments (2)

packages/util/src/functions/runtime.ts (1)

9-15: Cloudflare Workers short-circuit is correctly prioritized.

This check is in the right place (before the process.versions runtime branch) and correctly prevents Workers + nodejs_compat from falling into the Node.js path. It aligns with how runtime selection is consumed in packages/ws/src/ws/WebSocketShard.ts:87-89 and packages/rest/src/index.ts:7.

packages/util/__tests__/runtime.test.ts (1)

25-44: Runtime-branch coverage is solid for the new behavior.

The Workers (WebSocketPair) case plus Node, Deno, and Bun paths are clearly asserted and match the updated runtime detection contract.