semver for golang

semver is a Semantic Versioning library written in golang. It fully covers spec version 2.0.0.

Usage

$ go get github.com/blang/semver

Note: Always vendor your dependencies or fix on a specific version tag.

import github.com/blang/semver
v1, err := semver.New("1.0.0-beta")
v2, err := semver.New("2.0.0-beta")
v1.Compare(v2)

Also check the GoDocs.

Why should I use this lib?

• Fully spec compatible
• No reflection
• No regex
• Fully tested (Coverage >99%)
• Readable parsing/validation errors
• Fast (See Benchmarks)
• Only Stdlib
• Uses values instead of pointers
• Many features, see below

Features

• Parsing and validation at all levels
• Comparator-like comparisons
• Compare Helper Methods
• InPlace manipulation
• Sortable (implements sort.Interface)
• database/sql compatible (sql.Scanner/Valuer)

Example

Have a look at full examples in examples/main.go

import github.com/blang/semver

v, err := semver.New("0.0.1-alpha.preview+123.github")
fmt.Printf("Major: %d\n", v.Major)
fmt.Printf("Minor: %d\n", v.Minor)
fmt.Printf("Patch: %d\n", v.Patch)
fmt.Printf("Pre: %s\n", v.Pre)
fmt.Printf("Build: %s\n", v.Build)

// Prerelease versions array
if len(v.Pre) > 0 {
    fmt.Println("Prerelease versions:")
    for i, pre := range v.Pre {
        fmt.Printf("%d: %q\n", i, pre)
    }
}

// Build meta data array
if len(v.Build) > 0 {
    fmt.Println("Build meta data:")
    for i, build := range v.Build {
        fmt.Printf("%d: %q\n", i, build)
    }
}

v001, err := semver.New("0.0.1")
// Compare using helpers: v.GT(v2), v.LT, v.GTE, v.LTE
v001.GT(v) == true
v.LT(v001) == true
v.GTE(v) == true
v.LTE(v) == true

// Or use v.Compare(v2) for comparisons (-1, 0, 1):
v001.Compare(v) == 1
v.Compare(v001) == -1
v.Compare(v) == 0

// Manipulate Version in place:
v.Pre[0], err = semver.NewPRVersion("beta")
if err != nil {
    fmt.Printf("Error parsing pre release version: %q", err)
}

fmt.Println("\nValidate versions:")
v.Build[0] = "?"

err = v.Validate()
if err != nil {
    fmt.Printf("Validation failed: %s\n", err)
}

Benchmarks

BenchmarkParseSimple         5000000      328    ns/op    49 B/op   1 allocs/op
BenchmarkParseComplex        1000000     2105    ns/op   263 B/op   7 allocs/op
BenchmarkParseAverage        1000000     1301    ns/op   168 B/op   4 allocs/op
BenchmarkStringSimple       10000000      214    ns/op    16 B/op   2 allocs/op
BenchmarkStringComplex       3000000      583    ns/op    88 B/op   4 allocs/op
BenchmarkStringAverage       3000000      461    ns/op    56 B/op   3 allocs/op
BenchmarkValidateSimple    500000000        7.92 ns/op     0 B/op   0 allocs/op
BenchmarkValidateComplex     2000000      923    ns/op     0 B/op   0 allocs/op
BenchmarkValidateAverage     5000000      452    ns/op     0 B/op   0 allocs/op
BenchmarkCompareSimple     100000000       11.2  ns/op     0 B/op   0 allocs/op
BenchmarkCompareComplex     50000000       40.9  ns/op     0 B/op   0 allocs/op
BenchmarkCompareAverage     50000000       43.8  ns/op     0 B/op   0 allocs/op
BenchmarkSort                5000000      436    ns/op   259 B/op   2 allocs/op

See benchmark cases at semver_test.go

Motivation

I simply couldn‘t find any lib supporting the full spec. Others were just wrong or used reflection and regex which i don’t like.

Contribution

Feel free to make a pull request. For bigger changes create a issue first to discuss about it.

License

See LICENSE file.