Set custom version

Author: a-b

version/version.go

@@ -1,6 +1,8 @@
 package version
 
 import (
+	"fmt"
+	"os"
 	"strings"
 
 	"github.com/blang/semver/v4"
@@ -12,9 +14,25 @@ var (
 	binaryVersion   string
 	binarySHA       string
 	binaryBuildDate string
+	customVersion   string
 )
 
+func SetVersion(version string) {
+	_, err := semver.Parse(version)
+
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Unable to parse version: %s\n", err)
+		os.Exit(1)
+	}
+
+	customVersion = version
+}
+
 func VersionString() string {
+	if customVersion != "" {
+		return customVersion
+	}
+
 	// Remove the "v" prefix from the binary in case it is present
 	binaryVersion = strings.TrimPrefix(binaryVersion, "v")
 	versionString, err := semver.Make(binaryVersion)

version/version_test.go

@@ -1,6 +1,9 @@
 package version_test
 
 import (
+	"os"
+	"os/exec"
+
 	"code.cloudfoundry.org/cli/version"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -13,5 +16,36 @@ var _ = Describe("Version", func() {
 				Expect(version.VersionString()).To(Equal("0.0.0-unknown-version"))
 			})
 		})
+
+		When("a custom version is set", func() {
+			It("returns the custom version", func() {
+				version.SetVersion("1.2.3")
+				Expect(version.VersionString()).To(Equal("1.2.3"))
+			})
+		})
+	})
+
+	Describe("SetVersion", func() {
+		It("sets the version for valid semver versions", func() {
+			version.SetVersion("1.2.3")
+			Expect(version.VersionString()).To(Equal("1.2.3"))
+		})
+
+		It("exits with status code 1 when given an invalid semver", func() {
+			if os.Getenv("TEST_EXIT") == "1" {
+				version.SetVersion("not-a-semver")
+				Fail("Expected process to exit but it didn't")
+			}
+
+			cmd := exec.Command(os.Args[0], "-ginkgo.focus=exits with status code 1 when given an invalid semver")
+			cmd.Env = append(os.Environ(), "TEST_EXIT=1")
+
+			err := cmd.Run()
+			Expect(err).To(HaveOccurred())
+
+			exitErr, ok := err.(*exec.ExitError)
+			Expect(ok).To(BeTrue())
+			Expect(exitErr.ExitCode()).To(Equal(1))
+		})
 	})
 })