[BUG] X-Range with Prerelease Ignores Prerelease

[WalkerCodeRanger]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

A range like >=1.x.x-rc appears to ignore the -rc and be treated as equal to >=1.x.x. For example, it does not match the version 1.0.0-rc.1.

Expected Behavior

Since it isn't clear what prerelease versions >=1.x.x-rc should match, I think it should be an invalid range. If one really wanted to support it, then it would need to match multiple prerelease ranges (e.g. 1.0.0-rc, 1.0.5-rc, 1.5.6-rc, etc.).

Steps To Reproduce

As I am not a Node developer but rather a maintainer of a semver package for C# that needs to support npm style version ranges, I am using https://semver.npmjs.com/ to test. Simply put the listed versions into it.

[mbtools]

Ranges are mapped to so-called comparators which are a combination of a semantic version and an operator. Example:

node
> const Range = require('semver/classes/range')
undefined
> new Range('>=1.x.x-rc')
Range {
  options: {},
  loose: false,
  includePrerelease: false,
  raw: '>=1.x.x-rc',
  set: [ [ [Comparator] ] ],
  range: '>=1.0.0'
}

You can see the default behaviour of semver which is ignoring pre-releases. You get >=1.0.0. This explains why pre-releases like 1.0.0-rc.1 don't match since they are lower than 1.0.0 (i.e. "happening before on a timeline").

You can include prereleases via option:

> new Range('>=1.x.x-rc', { includePrerelease: true })
Range {
  options: { includePrerelease: true },
  loose: false,
  includePrerelease: true,
  raw: '>=1.x.x-rc',
  set: [ [ [Comparator] ] ],
  range: '>=1.0.0-0'
}

You get >=1.0.0-0 matching all pre-releases due to:

node-semver/classes/range.js

Lines 404 to 406 in 2677f2a

	// if we're including prereleases in the match, then we need
	// to fix this to -0, the lowest possible prerelease value
	pr = options.includePrerelease ? '-0' : ''

Here are your examples:

> new Range('>=1.x.x-rc').test('1.0.0-rc.1')
false
> new Range('>=1.x.x-rc', { includePrerelease: true }).test('1.0.0-rc.1')
true
> new Range('>=1.x.x-rc').test('1.0.5-rc.1')
false
> new Range('>=1.x.x-rc', { includePrerelease: true }).test('1.0.5-rc.1')
true
> new Range('>=1.x.x-rc').test('1.5.6-rc.1')
false
> new Range('>=1.x.x-rc', { includePrerelease: true }).test('1.5.6-rc.1')
true

Hope that helps. Works as designed 😃

[wraithgar]

Thanks @mbtools