fix: response correctly when receive an OPTIONS request

[TrickyPi]

• This is a bugfix
• This is a feature
• This is a code refactor
• This is a test update
• This is a docs update
• This is a metadata update

For Bugs and Features; did you add new tests?

Yes

Motivation / Use-Case

fix: #4180

Breaking Changes

No

Additional Info

No

[TrickyPi]

I try to run the test on my local machine. But it always hangs whenever it goes to the following steps.

RUNS test/cli/basic.test.js
RUNS test/cli/server-option.test.js
RUNS test/cli/https-option.test.js

[codecov]

Codecov Report

Merging #4185 (da16ee5) into master (83951c8) will decrease coverage by 0.08%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4185      +/-   ##
==========================================
- Coverage   92.20%   92.11%   -0.09%     
==========================================
  Files          16       16              
  Lines        1629     1637       +8     
  Branches      615      616       +1     
==========================================
+ Hits         1502     1508       +6     
- Misses        116      118       +2     
  Partials       11       11              

Impacted Files	Coverage Δ
lib/Server.js	93.75% <100.00%> (+0.04%)	⬆️
lib/servers/WebsocketServer.js	89.74% <0.00%> (-5.13%)	⬇️

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[snitin315]

I try to run the test on my local machine. But it always hangs whenever it goes to the following steps.

RUNS test/cli/basic.test.js RUNS test/cli/server-option.test.js RUNS test/cli/https-option.test.js

Make sure you have linked webpack-dev-server -

sudo npm link && npm link webpack-dev-server

[TrickyPi]

I try to run the test on my local machine. But it always hangs whenever it goes to the following steps.
RUNS test/cli/basic.test.js RUNS test/cli/server-option.test.js RUNS test/cli/https-option.test.js

Make sure you have linked webpack-dev-server -

sudo npm link && npm link webpack-dev-server

Oh, i didn't run this command. I'm sorry about i didn't read CONTRIBUTING.md carefully.

[alan-agius4]

@alexander-akait, any way we can get this in?

[alexander-akait]

@alan-agius4 Do you want this as built-in feature?

[alan-agius4]

Ideally, the dev-server can handle preflight requests out-of-the-box as it did in version 3.

[alexander-akait]

@alan-agius 4 interesting, because previously we don't handle it (i.e. we don't have code for this), it means one from middlewares handle this, I am not agait this merge, just want to check...

[alan-agius4]

@alexander-akait understood.

[alexander-akait]

@alan-agius4 Do you have time to check it (just a little busy right now), thank you

[TrickyPi]

Please let me know if some code needs to be changed, i would be happy to change it.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: TrickyPi / name: TrickyPi (a8b39c2, c373320)
• ✅ login: alexander-akait / name: Alexander Akait (3cf7f9f)

[TrickyPi]

a lot of differences in types/lib/Server.d.ts, is this normal?

[alan-agius4]

The OPTIONS request/response is handled by the express router https://github.com/expressjs/express/blob/master/lib/router/index.js#L164-L169

In version 4 however this check is always falsey, which causes the options not be handled properly.

In version 3 this worked because of the additional express Layer that caused the options to be handled.

setupMagicHtmlFeature() {
   this.app.get('*', this.serveMagicHtml.bind(this));
}

This is because the above cause a creation of an additional layer where Boolean(this.methods[name]) is.
https://github.com/expressjs/express/blob/7ec5dd2b3c5e7379f68086dae72859f5573c8b9b/lib/router/route.js#L58-L70 is false.

In fact adding the below in setupBuiltInRoutes in v4, the OPTIONS are also handled correctly.

app.get('*', (req, res, next) => { next(); });    

[alexander-akait]

@alan-agius4 thank for this, I think we can enable it by default, should be safe for dev env

@TrickyPi Can you enable it by default?

[TrickyPi]

Ok