Drive out errors

[#151229598]

Signed-off-by: Slawek Ligus <[email protected]>

cmd/compare.go

@@ -27,12 +27,12 @@ func NewCompare(stdout, stderr io.Writer) Compare {
 func (c Compare) Execute(args []string) error {
 	v1, err := semverMake(args[0])
 	if err != nil {
-		panic(err)
+		return err
 	}
 
 	v2, err := semverMake(args[1])
 	if err != nil {
-		panic(err)
+		return err
 	}
 
 	c.stdout.Write([]byte(fmt.Sprintf("%d\n", semverCompare(v1, v2))))

cmd/compare_test.go

@@ -2,6 +2,7 @@ package cmd_test
 
 import (
 	"bytes"
+	"errors"
 
 	"github.com/blang/semver"
 	"github.com/christianang/semver-cli/cmd"
@@ -53,5 +54,23 @@ var _ = Describe("Compare", func() {
 			Expect(fakeSemver.MakeArgsForCall(1)).To(Equal("1.12.5"))
 			Expect(stdout.String()).To(Equal("9999\n"))
 		})
+
+		Context("when an error occurs", func() {
+			Context("when the first semver is invalid", func() {
+				It("returns an error", func() {
+					fakeSemver.MakeReturnsOnCall(0, semver.Version{}, errors.New("failed to make"))
+					err := command.Execute([]string{"1.x.x.x", "1.12.5"})
+					Expect(err).To(MatchError("failed to make"))
+				})
+			})
+
+			Context("when the first semver is invalid", func() {
+				It("returns an error", func() {
+					fakeSemver.MakeReturnsOnCall(1, semver.Version{}, errors.New("failed to make"))
+					err := command.Execute([]string{"1.x.x.x", "1.12.5"})
+					Expect(err).To(MatchError("failed to make"))
+				})
+			})
+		})
 	})
 })