replace mocha with jest

[hiroppy]

• 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?

Motivation / Use-Case

#1649 (comment)

Breaking Changes

Additional Info

Currently, since duplication of ports occurred, the test is executed in series.
I would like to correspond with another PR.
If all CIs pass, remove wip.

[hiroppy]

It is strange to use spawn, the following error occurs.

 spawn node ENOENT

So We will use execa.

[alexander-akait]

Good job, let's wait CI green 👍

[codecov]

Codecov Report

Merging #1650 into master will increase coverage by 7.29%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1650      +/-   ##
==========================================
+ Coverage   75.14%   82.43%   +7.29%     
==========================================
  Files          10       15       +5     
  Lines         688      484     -204     
  Branches        0      120     +120     
==========================================
- Hits          517      399     -118     
+ Misses        171       68     -103     
- Partials        0       17      +17

Impacted Files	Coverage Δ
setupTest.js	100% <100%> (ø)
test/helpers/run-webpack-dev-server.js	92.59% <100%> (ø)
lib/utils/createCertificate.js	66.66% <0%> (-33.34%)	⬇️
lib/Server.js	78.9% <0%> (-2.61%)	⬇️
bin/options.js
bin/webpack-dev-server.js
examples/cli/public/webpack.config.js
bin/utils.js
examples/util.js
... and 9 more

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[alexander-akait]

@hiroppy hm, coverage is very decrease, something wrong?

[hiroppy]

hmmm.... I don't know that. Current setting is "collectCoverageFrom": ["(lib|bin)/**/*.js"],.

[hiroppy]

Test failed on appveyor.(Environment: nodejs_version=8, webpack_version=latest)

FAIL test/Routes.test.js
  ● Routes › headers as an array › GET request with headers as an array
    expected "X-Bar" of "key1=value1, key2=value2", got "key1=value1,key2=value2"
      at Test.Object.<anonymous>.Test._assertHeader (node_modules/supertest/lib/test.js:249:12)
      at Test.Object.<anonymous>.Test._assertFunction (node_modules/supertest/lib/test.js:283:11)
      at Test.Object.<anonymous>.Test.assert (node_modules/supertest/lib/test.js:173:18)
      at Server.assert (node_modules/supertest/lib/test.js:131:12)

[hiroppy]

@evilebottnawi Fixed. https://codecov.io/gh/webpack/webpack-dev-server/commit/dfe5bade21a4bd9f02b40cb497cefaee868adae0

[hiroppy]

The following error occurs only at Node 8 🤔(it also happened on my mac)

 expected "X-Bar" of "key1=value1, key2=value2", got "key1=value1,key2=value2"

[hiroppy]

@evilebottnawi Since I do not know the cause, I temporarily verified it.
I think that it is not good, but I think that the influence range is not so big either.(Because the core code is not rewritten)
29b320d

[alexander-akait]

Maybe just remove spaces from expected? I am afraid another version can also have same problem?

[hiroppy]

version	output	spaces
6	key1=value1, key2=value2	y
7	key1=value1,key2=value2	n
8	key1=value1,key2=value2	n
9	key1=value1,key2=value2	n
10	key1=value1, key2=value2	y
11	key1=value1, key2=value2	y

6, 10, 11 have the spaces but 7, 8, 9 don't have.

So, I change the code to ['v7', 'v8', 'v9'].includes.

[alexander-akait]

@hiroppy Can you send this change in commit?

[hiroppy]

added to https://github.com/webpack/webpack-dev-server/pull/1650/files#diff-f1603d639761fe762d975b5ce05e20b1R107

[hiroppy]

Separated this commit(10e4bc2) /cc @evilebottnawi

[alexander-akait]

Great job! One note

[alexander-akait]

@hiroppy Good job, let's wait CI green

[hiroppy]

@evilebottnawi Thanks for reviewing! CI is green:)

[alexander-akait]

@hiroppy let's improve CI testing

https://github.com/webpack/webpack-dev-server/blob/master/.travis.yml (need add 8 and 11)

https://github.com/webpack/webpack-dev-server/blob/master/appveyor.yml (need add node 11)

Maybe refactor and improve config (add cache)

Can you take care?

[hiroppy]

Yep, I'll work on that:)