From 9bdbe2afd3f43da7b18b373fccf8806f2b181359 Mon Sep 17 00:00:00 2001
From: Carlos Alexandro Becker <caarlos0@users.noreply.github.com>
Date: Fri, 13 Dec 2024 11:00:47 -0300
Subject: [PATCH] feat(version): adds command to check current gum version

closes #352

Signed-off-by: Carlos Alexandro Becker <caarlos0@users.noreply.github.com>
---
 go.mod             |  1 +
 go.sum             |  2 ++
 gum.go             | 11 +++++++++++
 main.go            |  1 +
 version/command.go | 25 +++++++++++++++++++++++++
 version/options.go |  6 ++++++
 6 files changed, 46 insertions(+)
 create mode 100644 version/command.go
 create mode 100644 version/options.go

diff --git a/go.mod b/go.mod
index 14d781e2b..dc913fdf8 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/charmbracelet/gum
 go 1.21
 
 require (
+	github.com/Masterminds/semver/v3 v3.3.1
 	github.com/alecthomas/kong v1.6.0
 	github.com/alecthomas/mango-kong v0.1.0
 	github.com/charmbracelet/bubbles v0.20.0
diff --git a/go.sum b/go.sum
index a1c5b5bfc..8c72ddd1f 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,7 @@
 github.com/MakeNowJust/heredoc v1.0.0 h1:cXCdzVdstXyiTqTvfqk9SDHpKNjxuom+DOlyEeQ4pzQ=
 github.com/MakeNowJust/heredoc v1.0.0/go.mod h1:mG5amYoWBHf8vpLOuehzbGGw0EHxpZZ6lCpQ4fNJ8LE=
+github.com/Masterminds/semver/v3 v3.3.1 h1:QtNSWtVZ3nBfk8mAOu/B6v7FMJ+NHTIgUPi7rj+4nv4=
+github.com/Masterminds/semver/v3 v3.3.1/go.mod h1:4V+yj/TJE1HU9XfppCwVMZq3I84lprf4nC11bSS5beM=
 github.com/alecthomas/assert/v2 v2.11.0 h1:2Q9r3ki8+JYXvGsDyBXwH3LcJ+WK5D0gc5E8vS6K3D0=
 github.com/alecthomas/assert/v2 v2.11.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
 github.com/alecthomas/chroma/v2 v2.14.0 h1:R3+wzpnUArGcQz7fCETQBzO5n9IMNi13iIs46aU4V9E=
diff --git a/gum.go b/gum.go
index 7a59f2077..41913141f 100644
--- a/gum.go
+++ b/gum.go
@@ -17,6 +17,7 @@ import (
 	"github.com/charmbracelet/gum/spin"
 	"github.com/charmbracelet/gum/style"
 	"github.com/charmbracelet/gum/table"
+	"github.com/charmbracelet/gum/version"
 	"github.com/charmbracelet/gum/write"
 )
 
@@ -214,4 +215,14 @@ type Gum struct {
 	// $ gum log --level info "Hello, world!"
 	//
 	Log log.Options `cmd:"" help:"Log messages to output"`
+
+	// VersionCheck provides a command that checks if the current gum version
+	// matches a given semantic version constraint.
+	//
+	// It can be used to check that a minimum gum version is installed in a
+	// script.
+	//
+	// $ gum version-check '~> 0.15'
+	//
+	VersionCheck version.Options `cmd:"" help:"Semver check current gum version"`
 }
diff --git a/main.go b/main.go
index 75741e2cd..18fa9f087 100644
--- a/main.go
+++ b/main.go
@@ -54,6 +54,7 @@ func main() {
 		}),
 		kong.Vars{
 			"version":                 version,
+			"versionNumber":           Version,
 			"defaultHeight":           "0",
 			"defaultWidth":            "0",
 			"defaultAlign":            "left",
diff --git a/version/command.go b/version/command.go
new file mode 100644
index 000000000..2a1752272
--- /dev/null
+++ b/version/command.go
@@ -0,0 +1,25 @@
+package version
+
+import (
+	"fmt"
+
+	"github.com/Masterminds/semver/v3"
+	"github.com/alecthomas/kong"
+)
+
+// Run check that a given version matches a semantic version constraint.
+func (o Options) Run(ctx *kong.Context) error {
+	c, err := semver.NewConstraint(o.Constraint)
+	if err != nil {
+		return fmt.Errorf("could not parse range %s: %w", o.Constraint, err)
+	}
+	current := ctx.Model.Vars()["versionNumber"]
+	v, err := semver.NewVersion(current)
+	if err != nil {
+		return fmt.Errorf("could parse version %s: %w", current, err)
+	}
+	if !c.Check(v) {
+		return fmt.Errorf("gum version %q is not within given range %q", current, o.Constraint)
+	}
+	return nil
+}
diff --git a/version/options.go b/version/options.go
new file mode 100644
index 000000000..2dbb19d95
--- /dev/null
+++ b/version/options.go
@@ -0,0 +1,6 @@
+package version
+
+// Options is the set of options that can be used with version.
+type Options struct {
+	Constraint string `arg:"" help:"Semantic version constraint"`
+}