fix: generation of negative flags

[snitin315]

What kind of change does this PR introduce?
bugfix

Did you add tests for your changes?
Yes
If relevant, did you update the documentation?
No need
Summary
fix generation of negative flags. currently, we have negative flags for all boolean flags regardless of option.negative value.

Does this PR introduce a breaking change?
No

Other information
No

[codecov]

Codecov Report

Merging #2555 (21cf48a) into master (d039472) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2555   +/-   ##
=======================================
  Coverage   90.98%   90.98%           
=======================================
  Files          29       29           
  Lines        1464     1464           
  Branches      419      419           
=======================================
  Hits         1332     1332           
  Misses        132      132           

Impacted Files	Coverage Δ
packages/webpack-cli/lib/webpack-cli.js	92.41% <ø> (ø)

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[snitin315]

/cc @webpack/cli-team

[alexander-akait]

@snitin315 we should better to solve it, I will finish your PR, dont' worry

[alexander-akait]

/cc @webpack/cli-team I want to clarify something here, we have three types:

• type: 'boolean' means --option and --no-option, any boolean for CLI always have positive and negative value
• type: 'enum' and values: [true] means only --option (no negative)
• type: 'enum' and values: [false] means only --no-option (no positive)

Here situation when you can use type: 'enum' and values: [false, true], it is possible, but it doesn't make sense, because it means boolean

[alexander-akait]

Also need review, we should merge it before release

[snitin315]

Here situation when you can use type: 'enum' and values: [false, true], it is possible, but it doesn't make sense, because it means boolean

Yes 'boolean' should be preferred here.

[anshumanv]

Much better

[alexander-akait]

@snitin315 Let's wait green #2553 and merge, then rebase

[alexander-akait]

/cc @webpack/cli-team need merge it the next, I think time to release