Add --version flag to the executable

.build.yml

@@ -122,8 +122,12 @@ tasks:
       twitter fetch_user michaelmalice
       twitter get_user_tweets michaelmalice
 
+      # Compile the binary with the version number
+      cd .. && ./compile.sh $version
+      cd outdated_profile
+
       # Now test the upgrade using the newer version
-      which ../tw  # Should be here from previous step
+      which ../tw
       ../tw fetch_user michaelmalice  # Any operation other than `create_profile` should trigger the upgrade
 
       duration=$SECONDS

cmd/compile.sh

@@ -3,5 +3,9 @@
 set -x
 set -e
 
-go build -ldflags="-s -w" -o tw ./twitter
+if [[ -n "$1" ]]; then
+	go build -ldflags="-s -w -X main.version_string=$1" -o tw ./twitter
+else
+	go build -ldflags="-s -w" -o tw ./twitter
+fi
 chmod +x tw

cmd/tests.sh

@@ -5,12 +5,15 @@ set -x
 
 PS4='+(${BASH_SOURCE}:${LINENO}): '
 
-./compile.sh
+FAKE_VERSION="1.100.3489"
+./compile.sh $FAKE_VERSION
 
 test -e data && rm -r data
 
 PATH=`pwd`:$PATH
 
+test "$(tw --version)" = "v$FAKE_VERSION"
+
 tw create_profile data
 cd data
 

cmd/twitter/main.go

@@ -13,19 +13,29 @@ import (
  */
 var profile persistence.Profile
 
+var version_string string
 
 /**
  * Main method
  */
 func main() {
-	if len(os.Args) < 3 {
-		die("", true, 0)
-	}
-
 	profile_dir := flag.String("profile", ".", "TODO USAGE")
+	flag.StringVar(profile_dir, "p", ".", "TODO USAGE")
+
+	show_version_flag := flag.Bool("version", false, "???")
+	flag.BoolVar(show_version_flag, "v", false, "???")
 	flag.Parse()
 	args := flag.Args()
 
+	if *show_version_flag {
+		if version_string == "" {
+			fmt.Println("Development version")
+		} else {
+			fmt.Println("v" + version_string)
+		}
+		os.Exit(0)
+	}
+
 	if len(args) < 2 {
 		die("", true, 1)
 	}