backup, simulator: Add Unit Tests For pd-backup And pd-simulator

[ihcsim]

What problem does this PR solve?

This PR adds unit tests to the tools/pd-backup/pdbackup and tools/pd-simulator/simulator packages, to improve their test coverage:

$ go test -cover ./tools/pd-backup/pdbackup/...                                                                                          
ok      github.com/tikv/pd/tools/pd-backup/pdbackup     0.257s  coverage: 77.8% of statements

$ go test -cover ./tools/pd-simulator/simulator/...                                                                                    
?       github.com/tikv/pd/tools/pd-simulator/simulator [no test files]
?       github.com/tikv/pd/tools/pd-simulator/simulator/cases   [no test files]
?       github.com/tikv/pd/tools/pd-simulator/simulator/info    [no test files]
ok      github.com/tikv/pd/tools/pd-simulator/simulator/simutil 0.030s  coverage: 85.5% of statements

Issue Number: ref #2290

Note:

• I am not sure if the new tests for TestGenerateSplitKey() are sufficient. Appreciate some feedback there.
• For ease of review, tests for tools/pd-ctl will be included in a separate PR because it will touch more files.

What is changed and how does it work?

Check List

Tests

• Unit test

Code changes

• Introduced unit tests

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• nolouch

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[codecov]

Codecov Report

Base: 75.48% // Head: 75.80% // Increases project coverage by +0.31% 🎉

Coverage data is based on head (6b2099a) compared to base (57dc015).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5571      +/-   ##
==========================================
+ Coverage   75.48%   75.80%   +0.31%     
==========================================
  Files         326      326              
  Lines       32259    32263       +4     
==========================================
+ Hits        24352    24456     +104     
+ Misses       5788     5714      -74     
+ Partials     2119     2093      -26     

Flag	Coverage Δ
unittests	75.80% <100.00%> (+0.31%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
server/schedule/placement/fit.go	88.50% <100.00%> (+0.27%)	⬆️
pkg/tempurl/tempurl.go	45.00% <0.00%> (-15.00%)	⬇️
server/schedulers/hot_region_v2.go	73.09% <0.00%> (-7.02%)	⬇️
server/region_syncer/server.go	82.41% <0.00%> (-4.95%)	⬇️
server/id/id.go	83.05% <0.00%> (-3.39%)	⬇️
pkg/dashboard/adapter/manager.go	79.31% <0.00%> (-2.30%)	⬇️
server/schedule/operator_controller.go	86.19% <0.00%> (-0.91%)	⬇️
server/cluster/cluster.go	83.66% <0.00%> (ø)
server/grpc_service.go	49.36% <0.00%> (+0.16%)	⬆️
server/server.go	75.44% <0.00%> (+0.37%)	⬆️
... and 14 more

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[nolouch]

LGTM! thanks for your contribution.

[nolouch]

/merge

[ti-chi-bot]

@nolouch: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

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[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 6b2099a

[ihcsim]

@nolouch Thanks for the merge. Can you label this PR with hacktoberfest-accepted so that it gets included in the ongoing Hacktoberfest event? UPDATE: the labeling is not necessary.