Add support for jbang. Fixes #18

.goreleaser.yml

@@ -49,10 +49,10 @@ snapcrafts:
     grade: stable
     confinement: strict
     publish: true
-    summary: "Gum is a Gradle/Maven wrapper written in Go"
+    summary: "Gum is a Gradle/Maven/jbang wrapper written in Go"
     description: |
-      Gum is a Gradle/Maven wrapper written in Go, inspired in https://github.com/dougborg/gdub and https://github.com/srs/gw.
-      Gum automatically detects if the project is Gradle or Maven based and runs the appropriate command. However in the case
+      Gum is a Gradle/Maven/jbang wrapper written in Go, inspired in https://github.com/dougborg/gdub and https://github.com/srs/gw.
+      Gum automatically detects if the project is Gradle, Maven, or jbang based and runs the appropriate command. However in the case
       that Gum guesses wrong you can force a specific build tool to be used.
 
       **Usage**
@@ -62,6 +62,7 @@ snapcrafts:
       * **-gd** displays debug information
       * **-gg** force Gradle build
       * **-gh** displays help information
+      * **-gj** force jbang execution
       * **-gm** force Maven build
       * **-gn** executes nearest build file
       * **-gq** run gm in quiet mode
@@ -79,5 +80,5 @@ brews:
       name: gum-homebrew-tap
     folder: Formula
     homepage: "https://github.com/kordamp/gm"
-    description: "Gum is a Gradle/Maven wrapper written in Go"
+    description: "Gum is a Gradle/Maven/jbang wrapper written in Go"
     skip_upload: false

README.adoc

@@ -13,11 +13,12 @@ image:https://img.shields.io/badge/donations-Patreon-orange.svg[link="https://ww
 
 ---
 
-Gum is a link:https://gradle.org[Gradle]/link:https:maven.apache.org[Maven] wrapper written in link:https://golang.org/[Go],
-inspired in link:https://github.com/dougborg/gdub[https://github.com/dougborg/gdub] and link:https://github.com/srs/gw[https://github.com/srs/gw].
+Gum is a link:https://gradle.org[Gradle]/link:https:maven.apache.org[Maven]/link:https://github.com/jbangdev[jbang] wrapper written in 
+link:https://golang.org/[Go], inspired in link:https://github.com/dougborg/gdub[https://github.com/dougborg/gdub] and 
+link:https://github.com/srs/gw[https://github.com/srs/gw].
 
-Gum automatically detects if the project is Gradle or Maven based and runs the appropriate command. However in the case that Gum guesses wrong you can force
-a specific build tool to be used.
+Gum automatically detects if the project is Gradle, Maven, or jbang based and runs the appropriate command. However in the case that Gum guesses wrong you can 
+force a specific build tool to be used.
 
 == Usage
 
@@ -26,6 +27,7 @@ Gum supports the following flags
 * *-gd* displays debug information
 * *-gg* force Gradle build
 * *-gh* displays help information
+* *-gj* force jbang execution
 * *-gm* force Maven build
 * *-gn* executes nearest build file
 * *-gq* run gm in quiet mode
@@ -76,6 +78,11 @@ $ gm verify
 
 Which results in the invocation of either *gradlew* or *gradle* with the *build* goal.
 
+.jbang
+
+Gum will execute a given file (local or remote) if explicitly defined, otherwise scans the the current directory and executes the first file with `.java` 
+or `.jsh` that's found.
+
 == Configuration
 
 You may configure some aspects of Gum using a link:https://github.com/toml-lang/toml[TOML] based configuration file.

gm.go

@@ -31,6 +31,7 @@ func main() {
 	var args []string
 	gradleBuild, args := gum.GrabFlag("-gg", os.Args[1:])
 	mavenBuild, args := gum.GrabFlag("-gm", args)
+	jbangBuild, args := gum.GrabFlag("-gj", args)
 	quiet, args := gum.GrabFlag("-gq", args)
 	version, args := gum.GrabFlag("-gv", args)
 	help, args := gum.GrabFlag("-gh", args)
@@ -50,6 +51,7 @@ func main() {
 		fmt.Println("  -gd\tdisplays debug information")
 		fmt.Println("  -gg\tforce Gradle build")
 		fmt.Println("  -gh\tdisplays help information")
+		fmt.Println("  -gj\tforce jbang execution")
 		fmt.Println("  -gm\tforce Maven build")
 		fmt.Println("  -gn\texecutes nearest build file")
 		fmt.Println("  -gq\trun gm in quiet mode")
@@ -58,8 +60,19 @@ func main() {
 		os.Exit(0)
 	}
 
-	if gradleBuild && mavenBuild {
-		fmt.Println("You cannot define both -gg and -gm flags at the same time")
+	count := 0
+	if gradleBuild {
+		count = count + 1
+	}
+	if mavenBuild {
+		count = count + 1
+	}
+	if jbangBuild {
+		count = count + 1
+	}
+
+	if count > 1 {
+		fmt.Println("You cannot define -gg, -gm, or -gj flags at the same time")
 		os.Exit(-1)
 	}
 
@@ -69,13 +82,16 @@ func main() {
 	} else if mavenBuild {
 		cmd := gum.FindMaven(gum.NewDefaultContext(quiet, true), args)
 		cmd.Execute()
+	} else if jbangBuild {
+		cmd := gum.FindJbang(gum.NewDefaultContext(quiet, true), args)
+		cmd.Execute()
 	} else {
-		findGradleOrMaven(quiet, args)
+		findTool(quiet, args)
 	}
 }
 
 // Attempts to execute gradlew/gradle first then mvnw/mvn
-func findGradleOrMaven(quiet bool, args []string) {
+func findTool(quiet bool, args []string) {
 	context := gum.NewDefaultContext(quiet, false)
 
 	gradle := gum.FindGradle(context, args)
@@ -90,7 +106,13 @@ func findGradleOrMaven(quiet bool, args []string) {
 		os.Exit(0)
 	}
 
-	fmt.Println("Did not find a Gradle nor Maven project")
+	jbang := gum.FindJbang(context, args)
+	if jbang != nil {
+		jbang.Execute()
+		os.Exit(0)
+	}
+
+	fmt.Println("Did not find a Gradle, Maven, or jbang project")
 	os.Exit(-1)
 }