fix(mock): emit server event after app ready so onServer runs

[elrrrrrrr]

What's the problem this PR solves?

In single-process mock mode (mm.app()), egg core's onServer() never runs, so the http server gets no clientError handler (and graceful shutdown / server timeout / websocket wiring is skipped too). Symptom: a malformed request that triggers clientError is not logged.

Root cause

@eggjs/mock creates the http server and emits server inside createServer(), which runs before await app.ready(). But egg core registers its server listener inside Application.load() (which runs during app.ready()), and onServer reads loaded config. So the event is emitted before the listener exists (and before config is loaded) → it's lost → onServer never runs.

egg3 (worked) — config loaded synchronously, listener registered in the constructor

new App() ─┬─ loader.load()  →  CONFIG loaded         ┐ all in the
           └─ bindEvents()   →  once('server') listener┘ constructor (sync)
mock.createServer() ──emit('server')──▶ onServer ✅  (config ready, listener ready)

egg4 (broken) — async loader moved listener registration into load()

new App()            → constructor does nothing
mock.createServer()  → emit('server') ✗ no listener yet, config not loaded  ← LOST
await app.ready()
   └─ super.load()   → CONFIG loaded + app.js/plugins register on('server')
   └─ bindEvents()   → registers once('server')  ← too late
=> onServer never runs ❌  (clientError logging etc. broken)

This PR — emit once, after ready

mock.createServer()  → only creates + caches the server, sets app.server (NO emit)
await app.ready()
   └─ super.load()   → CONFIG loaded + plugins register on('server')
   └─ bindEvents()   → registers once('server') + onServer
app.emit('server')   → the only emit → onServer ✅ + plugins ✅   (all fire exactly once)

The fix

Stop emitting server inside createServer() (it now only creates & caches the server, so app.server stays available during boot exactly as before), and emit it once, after await app.ready() in both the single (lib/app.ts) and parallel (lib/parallel/app.ts) app workers:

createServer(app);           // create + cache server only
await app.ready();
if (app.server) {
  app.emit('server', app.server);   // listener registered + config loaded → onServer runs
}

This:

• emits server exactly once, after the listener is registered and config is loaded (no double-emit, no premature onServer);
• keeps createServer before ready (so app.server is available during boot — the intentional ordering from More security tips #98 is preserved);
• mirrors @eggjs/cluster, which also emits server after the app is ready (the behaviour More security tips #98 originally referenced).

Alternatives considered (and rejected)

• Register the server listener in the constructor (restore egg3 timing): ❌ crashes — onServer reads this.config, which isn't loaded until app.ready(), so firing it at the pre-ready emit throws. This is exactly why egg4 moved the registration into load().
• Move createServer() to after app.ready(): ❌ shifts app-boot microtask timing and turns unrelated boot-error fixtures (e.g. plugins/multipart, cluster-client-error) into unhandled errors → CI red. Keeping createServer before ready and only relocating the emit avoids this.
• Re-emit server after ready (keep the early emit too): works, but emits twice; the early emit can double-fire server listeners registered before ready. Removing the early emit is cleaner.

Test

Added a regression guard in plugins/mock/test/app.test.ts: after app.ready(), assert app.server has a clientError listener (i.e. onServer ran). It fails before this change (count 0) and passes after.

Validation

Verified against a real egg4 framework (chair, @eggjs/mock@7.0.2-beta.9): a should log error when 400 test (raw malformed request → expect log) failed because clientError wasn't wired. With this change it passes deterministically.

🤖 Generated with Claude Code

[coderabbitai]

📝 Walkthrough

Walkthrough

createServer() no longer emits the 'server' event at creation time. Instead, both MockApplicationWorker._init and MockParallelApplication._init now emit the event after await app.ready() completes, ensuring Egg's listener (registered during load/ready) is in place before the event fires. A new regression test confirms the clientError listener is attached post-ready.

Changes

Server Event Emission Timing Fix

Layer / File(s)	Summary
Remove server event from createServer() and document post-ready requirement plugins/mock/src/lib/mock_http_server.ts	createServer() no longer calls app.emit('server', server) after creating the HTTP server. Comments explain that Egg registers the listener during Application.load()/app.ready(), so the event must be emitted by the caller after that point.
Add post-ready server event emission in both application variants plugins/mock/src/lib/app.ts, plugins/mock/src/lib/parallel/app.ts	Both MockApplicationWorker._init and MockParallelApplication._init now conditionally emit 'server' after await app.ready() (when app.server exists), ensuring the listener registered by Egg during ready is in place before the event fires.
Regression test for listener attachment plugins/mock/test/app.test.ts	New test case creates an app with cache: false, awaits ready(), asserts app.server is set, and confirms listenerCount('clientError') > 0 to verify the listener was successfully attached.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Suggested reviewers

• killagu

Poem

🐇 The server event hops with care,
Not born when created in the air.
But waits for ready() to conclude,
So listeners are waxed and brewed.
A timing dance, both old and new,
This bunny's precision rings true! 🥕

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main fix: emitting the server event after app ready so onServer runs, which directly addresses the root cause described in the PR objectives.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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[gemini-code-assist]

Code Review

This pull request adjusts the initialization order in MockApplicationWorker to await app.ready() before invoking createServer(app). This ensures that the server event is not emitted before egg core registers its listener, preventing the loss of critical event bindings like clientError. A new test case has been added to verify that the clientError listener is successfully attached after initialization. No review comments were provided, so there is no additional feedback to address.

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[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.53%. Comparing base (0333c73) to head (464503c).

Files with missing lines	Patch %	Lines
plugins/mock/src/lib/parallel/app.ts	0.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #5969      +/-   ##
==========================================
+ Coverage   85.50%   85.53%   +0.02%     
==========================================
  Files         669      669              
  Lines       19825    19828       +3     
  Branches     3917     3919       +2     
==========================================
+ Hits        16952    16960       +8     
+ Misses       2481     2477       -4     
+ Partials      392      391       -1     

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[Copilot]

Pull request overview

This PR fixes a lifecycle ordering bug in @eggjs/mock single-process mode where the mock HTTP server was created (and the server event emitted) before Egg core registers its once('server', ...) listener during app.ready(), causing Application.onServer() not to run and leaving clientError (and related server wiring) uninitialized.

Changes:

• Move mock HTTP server creation (createServer(app)) to run after await app.ready() in single-process mock initialization.
• Add a regression test asserting that clientError is wired on app.server after app.ready().

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
plugins/mock/src/lib/app.ts	Reorders initialization so createServer() runs after app.ready() to avoid losing the server event and ensure onServer() executes.
plugins/mock/test/app.test.ts	Adds a regression test verifying app.server has a clientError listener after readiness.

[fengmk2]

@codex review

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@plugins/mock/test/app.test.ts`:
- Around line 90-101: The test function creates an app and performs assertions,
but if any assertion fails, the app.close() cleanup call is skipped, causing
state leakage. Restructure the code by moving the await app.ready() call and all
assertions into a try block, then place await app.close() in a finally block to
ensure cleanup always executes regardless of assertion failures.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 0333c73 and 68a72fd.

📒 Files selected for processing (2)

• plugins/mock/src/lib/app.ts
• plugins/mock/test/app.test.ts

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[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🎉

Reviewed commit: 68a72fdf13

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.