[miniflare] Fix resource leaks during config updates

[petebacondarwin]

Fixes #13584, #13585.

Follow-up to #13515 addressing two resource-cleanup issues identified during review:

devRegistryDispatcher unconditionally closed on every config update (#13584):
The #devRegistryDispatcher was torn down and rebuilt on every #assembleAndUpdateConfig() call, regardless of whether the port changed. This is inconsistent with #runtimeDispatcher (which only recreates when the entry URL changes) and could cause brief request failures if #pushRegistryUpdate() is in-flight when the pool is closed. Fixed by tracking the port and only closing/recreating when it actually changes.

Old InspectorProxy instances not disposed during updateConnection (#13585):
InspectorProxyController.updateConnection() replaced this.#proxies with new InspectorProxy instances without first disposing the old ones. This leaked runtime WebSocket connections and their 10-second keepalive interval timers. Fixed by disposing old proxies before replacement.

---

• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows:
  • Additional testing not necessary because: existing miniflare test suite (734 tests) passes; both fixes are straightforward resource-cleanup changes with no behavioral impact beyond preventing leaks
• Public documentation
  • Documentation not necessary because: internal implementation fix with no user-facing API change

---

[changeset-bot]

🦋 Changeset detected

Latest commit: dc5a137

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[workers-devprod]

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[github-actions]

Changeset Review

File Reviewed

• .changeset/miniflare-dispose-cleanup-followup.md

Summary

✅ All changesets look good

Details

The changeset for miniflare is well-written:

• Version Type: patch is correctly chosen for bug fixes addressing resource leaks
• Description Quality: Clear title and detailed explanation of two specific follow-up fixes
  • Dev-registry dispatcher now only closes when port actually changes
  • InspectorProxy instances are now properly disposed during updates
• No Headers: Uses plain text and bullet points (no h1/h2/h3)
• Context: References PR [miniflare] Close all open handles on dispose to prevent process hangs #13515 for additional context
• Technical Detail: Explains what was broken and how it was fixed without being overly verbose

[ask-bonk]

I've now reviewed all the changed files thoroughly. Let me analyze the changes:

Change 1: packages/miniflare/src/index.ts - The #devRegistryDispatcher is now only closed/recreated when devRegistryPort !== this.#devRegistryPort. A new #devRegistryPort field tracks the previous port value. This mirrors how #runtimeDispatcher is handled (only recreated when #runtimeEntryURL changes, line 2411).

Change 2: packages/miniflare/src/plugins/core/inspector-proxy/inspector-proxy-controller.ts - Old InspectorProxy instances are disposed before being replaced in updateConnection(). The dispose() method (line 163-168 in inspector-proxy.ts) clears the keepalive interval and closes both the devtools and runtime WebSocket connections.

Both changes are correct, straightforward, and well-scoped. The changeset is appropriate. I don't see any logic bugs, race conditions, or backward compatibility issues:

1. For the dispatcher change, the initial call works correctly because #devRegistryPort starts as undefined, and if devRegistryPort from maybeSocketPorts.get(SOCKET_DEV_REGISTRY) is also undefined (no port), the comparison undefined !== undefined is false, so we correctly skip recreation. If it's a real port, realPort !== undefined is true, so we correctly create the dispatcher.

2. For the inspector proxy change, the dispose() on InspectorProxy is safe to call (just clears an interval and closes WebSockets), and the await ensures cleanup completes before new proxies are created.

LGTM

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.

[pkg-pr-new]

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commit: dc5a137

[workers-devprod]

Codeowners reviews satisfied