server: improve test coverage of /debug/zip api

[Deardrops]

What problem does this PR solve?

Improving test coverage of server package

Add test coverage for

tidb/server/http_status.go

Lines 204 to 228 in b274eb2

	// dump config
	fw, err = zw.Create("config")
	if err != nil {
	serveError(w, http.StatusInternalServerError, fmt.Sprintf("Create zipped %s fail: %v", "config", err))
	return
	}
	js, err := json.MarshalIndent(config.GetGlobalConfig(), "", " ")
	if err != nil {
	serveError(w, http.StatusInternalServerError, fmt.Sprintf("get config info fail%v", err))
	return
	}
	_, err = fw.Write(js)
	terror.Log(err)
	// dump version
	fw, err = zw.Create("version")
	if err != nil {
	serveError(w, http.StatusInternalServerError, fmt.Sprintf("Create zipped %s fail: %v", "version", err))
	return
	}
	_, err = fw.Write([]byte(printer.GetTiDBInfo()))
	terror.Log(err)
	err = zw.Close()
	terror.Log(err)

What is changed and how it works?

For testing /debug/zip api, We copy data in the http response to local temp file for ensuring data transport finished. This way also ensure all logic in /debug/zip will executed.

This PR is part of #11760

Check List

Tests

• Integration test

[sre-bot]

Thanks for your PR.
This PR will be closed by bot because you already had 3 opened PRs, close or merge them before submitting a new one.
#12550 , #13168 , #13211

[sre-bot]

Thanks for your PR.
This PR will be closed by bot because you already had 3 opened PRs, close or merge them before submitting a new one.
#12550 , #13168 , #13211

[codecov]

Codecov Report

Merging #13486 into master will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             master     #13486   +/-   ##
===========================================
  Coverage   79.9716%   79.9716%           
===========================================
  Files           473        473           
  Lines        116200     116200           
===========================================
  Hits          92927      92927           
  Misses        15945      15945           
  Partials       7328       7328

[Deardrops]

/run-all-tests

[Deardrops]

/run-all-tests

[Deardrops]

/run-unit-test

[Deardrops]

/run-unit-test

[Deardrops]

/run-unit-test

[Deardrops]

/run-unit-test

[Deardrops]

/run-unit-test

[Deardrops]

/run-unit-test

[djshow832]

LGTM

[reafans]

LGTM

[wjhuang2016]

LGTM, please add the coverage diff next time. From the picture, this PR will improve the coverage from 63.5% to 63.8%

[Deardrops]

/run-all-tests

[Deardrops]

/run-all-tests

[Deardrops]

/run-unit-test