feat: --jsh to allow forcing .jsh (quarkusio#658)

Main usecase is that tools like bach uses suffix less files.

for example to allow building https://github.com/jbee/purejin
using `jbang --jsh --java 16 https://bit.ly/bach-main-build`

itests/hellojsh

@@ -0,0 +1,3 @@
+// example of jsh without suffix.
+// use jbang --jsh to force it.
+System.out.println(args[0]);

itests/jsh.feature

@@ -24,7 +24,11 @@ Scenario: jsh quoted system property
 When command('jbang -Dvalue="a quoted" hello.jsh')
 Then match out == "a quoted\n"
 
-
 Scenario: jsh fail on --native
   When command('jbang --native hello.jsh')
   Then match err contains ".jsh cannot be used with --native"
+
+Scenario: force jsh
+  When command('jbang --jsh hellojsh hello')
+  Then match err == ""
+  Then match out == "hello\n"

src/main/java/dev/jbang/Script.java

@@ -72,6 +72,11 @@ public class Script {
 	 **/
 	private String javaAgentOption;
 
+	/**
+	 * if true, interpret any input as for jshell
+	 */
+	private boolean forcejsh = false;
+
 	public Script(ScriptResource resource, List<String> arguments, Map<String, String> properties)
 			throws FileNotFoundException {
 		this(resource, getBackingFileContent(resource.getFile()), arguments, properties);
@@ -437,7 +442,7 @@ public boolean needsJar() {
 	}
 
 	public boolean forJShell() {
-		return getBackingFile().getName().endsWith(".jsh");
+		return forcejsh || getBackingFile().getName().endsWith(".jsh");
 	}
 
 	public void setOriginal(String ref) {
@@ -658,4 +663,8 @@ public List<KeyValue> getAgentOptions() {
 		return agentOptions;
 	}
 
+	public void setForcejsh(boolean forcejsh) {
+		this.forcejsh = forcejsh;
+	}
+
 }

src/main/java/dev/jbang/Util.java

@@ -400,7 +400,8 @@ public static Path downloadFileSwizzled(String fileURL, File saveDir) throws IOE
 		// to handle if kubectl-style name (i.e. extension less)
 		File f = path.toFile();
 		String nonkebabname = f.getName();
-		if (!f.getName().endsWith(".jar")) { // avoid directly downloaded jar files getting renamed to .java
+		if (!f.getName().endsWith(".jar") && !f.getName().endsWith(".jsh")) { // avoid directly downloaded jar files
+																				// getting renamed to .java
 			nonkebabname = unkebabify(f.getName());
 		}
 		if (nonkebabname.equals(f.getName())) {

src/main/java/dev/jbang/cli/BaseScriptCommand.java

@@ -56,6 +56,9 @@ public abstract class BaseScriptCommand extends BaseCommand {
 			"--insecure" }, description = "Enable insecure trust of all SSL certificates.", defaultValue = "false")
 	boolean insecure;
 
+	@CommandLine.Option(names = { "--jsh" }, description = "Force input to be interpreted with jsh/jshell")
+	boolean forcejsh = false;
+
 	@CommandLine.Parameters(index = "0", arity = "1", description = "A file with java code or if named .jsh will be run with jshell")
 	String scriptOrFile;
 
@@ -106,11 +109,11 @@ public static Script prepareScript(String scriptResource, List<String> arguments
 
 	public static Script prepareScript(String scriptResource, List<String> arguments, Map<String, String> properties,
 			List<String> dependencies, List<String> classpaths) throws IOException {
-		return prepareScript(scriptResource, arguments, properties, dependencies, classpaths, false);
+		return prepareScript(scriptResource, arguments, properties, dependencies, classpaths, false, false);
 	}
 
 	public static Script prepareScript(String scriptResource, List<String> arguments, Map<String, String> properties,
-			List<String> dependencies, List<String> classpaths, boolean fresh)
+			List<String> dependencies, List<String> classpaths, boolean fresh, boolean forcejsh)
 			throws IOException {
 		ScriptResource scriptFile = getScriptFile(scriptResource);
 
@@ -156,6 +159,7 @@ public static Script prepareScript(String scriptResource, List<String> arguments
 		Script s = null;
 		try {
 			s = new Script(scriptFile, arguments, properties);
+			s.setForcejsh(forcejsh);
 			s.setOriginal(scriptResource);
 			s.setAlias(alias);
 			s.setAdditionalDependencies(dependencies);

src/main/java/dev/jbang/cli/Run.java

@@ -68,7 +68,8 @@ public Integer doCall() throws IOException {
 			enableInsecure();
 		}
 
-		script = prepareArtifacts(prepareScript(scriptOrFile, userParams, properties, dependencies, classpaths, fresh));
+		script = prepareArtifacts(
+				prepareScript(scriptOrFile, userParams, properties, dependencies, classpaths, fresh, forcejsh));
 
 		String cmdline = generateCommandLine(script);
 		debug("run: " + cmdline);
@@ -125,7 +126,7 @@ String generateCommandLine(Script script) throws IOException {
 
 			String requestedJavaVersion = javaVersion != null ? javaVersion : script.javaVersion();
 			String javacmd = resolveInJavaHome("java", requestedJavaVersion);
-			if (script.getBackingFile().getName().endsWith(".jsh")) {
+			if (script.forJShell()) {
 
 				javacmd = resolveInJavaHome("jshell", requestedJavaVersion);
 				if (!classpath.trim().isEmpty()) {