Version v1.0.2-alpha.0 should be greater than v1.0.1 but version.NewConstraint(...).Check returns false

[sebastian-sommerfeld-io]

Hey guys ... I stumbled upon this issue while implementing a tool to validate versions when I release one of my github projects. I want to make sure, that the version for my next release is greater than the latest version.

When checking for pre-release versions (alpha / beta) I stumbled upon a bug (from my point of view):

• Given my latest version is v1.0.1 which is a stable release
• When I check if v1.0.2 is greater than v1.0.1 then everything works fine
• When I check if v1.0.2-alpha.0 is greater than v1.0.1 then the result is false ... my expectation is that this check would pass, because I increased the minor version and marked it as unstable.
• When I check if v1.0.2-alpha.1 is greater than v1.0.2-alpha.0 then everything works fine again.

I wrote a short testcase in Go to validate

issue.go:

package services

import (
	"fmt"

	"github.com/hashicorp/go-version"
)

// The next version should be greater that the current version
func IsGreater(current string, next string) bool {
	parsedCurrent, err := version.NewVersion(current)
	if err != nil {
		fmt.Print(err)
		return false
	}

	parsedNext, err := version.NewVersion(next)
	if err != nil {
		fmt.Print(err)
		return false
	}

	// should be greater that current version
	constraint, err := version.NewConstraint("> " + parsedCurrent.Original())
	if err != nil {
		fmt.Print(err)
		return false
	}

	if !constraint.Check(parsedNext) {
		fmt.Print("next version " + parsedNext.Original() + " is not greater that current version " + parsedCurrent.Original())
	}
	return constraint.Check(parsedNext)
}

issue_test.go:

package services

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

func Test_ShouldBeGreater(t *testing.T) {
	testCases := []struct {
		currentVersion string
		nextVersion    string
		shouldBeValid  bool
	}{
		{"v1.0.1", "v1.0.2", true},
		{"v1.0.1", "v1.1.0", true},
		{"v1.0.1", "v2.0.0", true},
		{"v1.0.1", "v1.0.2-alpha.0", true}, // fails but should be true
		{"v1.0.1", "v1.0.2-beta.0", true},  // fails but should be true
		{"v1.0.2-alpha.0", "v1.0.2-alpha.1", true},
		{"v1.0.2-alpha.0", "v1.0.2-beta.0", true},
		{"v1.0.2-beta.1", "v1.0.2-beta.2", true},
		{"v1.0.2-alpha.0", "v1.0.2", true},
		{"v1.0.2-beta.0", "v1.0.2", true},
		{"v1.0.2", "v1.0.2", false},
		{"v1.0.2", "v1.0.1", false},
		{"v1.0.2-beta.0", "v1.0.2-alpha.0", false},
		{"v1.0.2-beta.2", "v1.0.2-beta.1", false},
		{"v2.0.0", "v2.0.0", false},
	}
	for _, tc := range testCases {
		assert := assert.New(t)
		got := IsGreater(tc.currentVersion, tc.nextVersion)

		assert.NotNil(got)
		assert.Equal(tc.shouldBeValid, got, "Result did not meet expectation - next version = "+tc.nextVersion+", current version = "+tc.currentVersion)
	}
}

Could you take a look into this please? Feel free to reach out to me for information if you feel the need. Best regards.

[kke]

I don't know if it is mentioned in the docs, but the implementation and code comments are here: https://github.com/hashicorp/go-version/blob/main/constraint.go#L197-L215

	case cPre && vPre:
		// A constraint with a pre-release can only match a pre-release version
		// with the same base segments.
		return reflect.DeepEqual(c.Segments64(), v.Segments64())

	case !cPre && vPre:
		// A constraint without a pre-release can only match a version without a
		// pre-release.
		return false

So, it's intentional.