fix: number enum generated schema type

[habiiev]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Currently, if you create a number enum property like this:

@ApiParam({ enum: [1, 2, 3] })

It will then generate a correct schema for this param:

{
  "type": "number",
  "enum": [1, 2, 3]
}

But if you add an “enumName“ parameter, so that the enum will get its own schema entry like this:

@ApiParam({ enum: [1, 2, 3], enumName: "ParamEnumName" })

It will change the type of the enum in the schema from 'number' to 'string':

{
  "ParamEnumName": {
    "type": "string",
    "enum": [
      1,
      2,
      3
    ]
  }
}

What is the new behavior?

I made it so it saves the type, if is was given before.

So if we take our previous example:

@ApiParam({ enum: [1, 2, 3], enumName: "ParamEnumName" })

It will now generate a correct schema for this enum:

{
  "ParamEnumName": {
    "type": "number",
    "enum": [
      1,
      2,
      3
    ]
  }
}

Does this PR introduce a breaking change?

• Yes
• No

Other information

[kamilmysliwiec]

lgtm