[in] create /version file based on git tag name

README.md

@@ -28,7 +28,10 @@ Fetches artifacts from the given release version. If the version is not
 specified, the latest version is chosen using [semver](http://semver.org)
 semantics.
 
-Creates a file `tag` containing the tag name/version of the release being fetched.
+Also creates the following files:
+
+* `tag` containing the git tag name of the release being fetched.
+* `version` containing the version determined by the git tag of the release being fetched.
 
 #### Parameters
 

in_command.go

@@ -65,6 +65,13 @@ func (c *InCommand) Run(destDir string, request InRequest) (InResponse, error) {
 		return InResponse{}, err
 	}
 
+	version := determineVersionFromTag(*foundRelease.TagName)
+	versionPath := filepath.Join(destDir, "version")
+	err = ioutil.WriteFile(versionPath, []byte(version), 0644)
+	if err != nil {
+		return InResponse{}, err
+	}
+
 	assets, err := c.github.ListReleaseAssets(foundRelease)
 	if err != nil {
 		return InResponse{}, err

in_command_test.go

@@ -236,7 +236,7 @@ var _ = Describe("In Command", func() {
 				))
 			})
 
-			It("stores tag in a file", func() {
+			It("stores git tag in a file", func() {
 				_, err := os.Stat(filepath.Join(destDir, "tag"))
 				Ω(err).ShouldNot(HaveOccurred())
 
@@ -246,6 +246,16 @@ var _ = Describe("In Command", func() {
 				Ω(string(tag)).Should(Equal("v0.35.0"))
 			})
 
+			It("stores version in a file", func() {
+				_, err := os.Stat(filepath.Join(destDir, "version"))
+				Ω(err).ShouldNot(HaveOccurred())
+
+				version, err := ioutil.ReadFile(filepath.Join(destDir, "version"))
+				Ω(err).ShouldNot(HaveOccurred())
+
+				Ω(string(version)).Should(Equal("0.35.0"))
+			})
+
 			It("fetches from the latest release", func() {
 				_, err := os.Stat(filepath.Join(destDir, "example.txt"))
 				Ω(err).ShouldNot(HaveOccurred())

versions.go

@@ -0,0 +1,10 @@
+package resource
+
+import "regexp"
+
+// determineVersionFromTag converts git tags v1.2.3 into semver 1.2.3 values
+func determineVersionFromTag(tag string) string {
+	re := regexp.MustCompile("v?([^v].*)")
+	matches := re.FindStringSubmatch(tag)
+	return matches[1]
+}