fix: allow just h2@

src/main/java/dev/jbang/catalog/Alias.java

@@ -190,6 +190,9 @@ private static Alias merge(Alias a1, String name, Function<String, Alias> findUn
 		if (parts.length > 2 || parts[0].isEmpty()) {
 			throw new RuntimeException("Invalid alias name '" + name + "'");
 		}
+		if (parts.length == 1 && name.endsWith("@")) {
+			parts = new String[] { parts[0], "jbangdev" };
+		}
 		Alias a2;
 		if (parts.length == 1) {
 			a2 = findUnqualifiedAlias.apply(name);

src/main/java/dev/jbang/catalog/Catalog.java

@@ -28,6 +28,8 @@
 import dev.jbang.util.Util;
 
 public class Catalog {
+	public static final String JBANG_DEFAULT_CATALOG = "jbangapp";
+
 	public static final String JBANG_CATALOG_JSON = "jbang-catalog.json";
 	public static final String JBANG_IMPLICIT_CATALOG_JSON = "implicit-catalog.json";
 
@@ -415,10 +417,14 @@ public static boolean isValidName(String name) {
 
 	public static boolean isValidCatalogReference(String name) {
 		String[] parts = name.split("@");
-		if (parts.length != 2 || parts[0].isEmpty() || parts[1].isEmpty()) {
+		switch (parts.length) {
+		case 1:
+			return isValidName(parts[0]);
+		case 2:
+			return isValidName(parts[0]); // should validate catalog ref is valid?
+		default:
 			return false;
 		}
-		return isValidName(parts[0]);
 	}
 
 }

src/main/java/dev/jbang/catalog/ImplicitCatalogRef.java

@@ -53,10 +53,11 @@ public static ImplicitCatalogRef parse(String name) {
 			return null;
 		}
 		String org = null;
-		if (names.length > 2) {
+		if (names.length >= 1) {
 			org = names[0];
+		} else {
+			org = Catalog.JBANG_DEFAULT_CATALOG; // TODO: should global default be controllable by config?
 		}
-		org = "jbangapp"; // TODO: should global default be controllable by config?
 		String repo;
 		if (names.length >= 2 && !names[1].isEmpty()) {
 			repo = names[1];

src/test/java/dev/jbang/TestImplicitAlias.java

@@ -10,6 +10,7 @@
 import org.junit.jupiter.api.Test;
 
 import dev.jbang.catalog.Alias;
+import dev.jbang.catalog.Catalog;
 import dev.jbang.catalog.ImplicitCatalogRef;
 import dev.jbang.cli.ExitException;
 
@@ -18,6 +19,16 @@
  */
 public class TestImplicitAlias extends BaseTest {
 
+	@Test
+	public void testValidity() {
+		assertThat(Catalog.isValidCatalogReference("h2@org/repo"), Matchers.is(true));
+		assertThat(Catalog.isValidCatalogReference("h2@org"), Matchers.is(true));
+		assertThat(Catalog.isValidCatalogReference("h2@/org"), Matchers.is(true));
+		assertThat(Catalog.isValidCatalogReference("h2@"), Matchers.is(true));
+		assertThat(Catalog.isValidCatalogReference("h2@/"), Matchers.is(false));
+
+	}
+
 	@Test
 	public void testGitImplicitCatalog() {
 		assertThat(ImplicitCatalogRef.getImplicitCatalogUrl("jbangdev").get(),
@@ -32,6 +43,7 @@ public void testDefaultImplicitCatalog() {
 				Matchers.equalTo("https://github.com/jbangapp/jbang-catalog/blob/HEAD/jbang-catalog.json"));
 		assertThat(ImplicitCatalogRef.getImplicitCatalogUrl("/sqlline").get(),
 				Matchers.equalTo("https://github.com/jbangapp/sqlline/blob/HEAD/jbang-catalog.json"));
+
 	}
 
 	@Test
@@ -46,11 +58,31 @@ public void testDefaultCatalogGet() {
 	}
 
 	@Test
-	public void testImplictURLAlias() {
+	public void testjbangapph2atapp() {
+		Alias url = Alias.get("h2@jbangapp");
+		assertThat(url.catalog.catalogRef.getOriginalResource(),
+				Matchers.equalTo("https://github.com/jbangapp/jbang-catalog/blob/HEAD/jbang-catalog.json"));
+	}
+
+	@Test
+	public void testjbangapph2at() {
+		Alias url = Alias.get("h2@");
+		assertThat(url.catalog.catalogRef.getOriginalResource(),
+				Matchers.equalTo("https://github.com/jbangapp/jbang-catalog/blob/HEAD/jbang-catalog.json"));
+
+	}
+
+	@Test
+	public void testjbangappsqlline() {
+		Alias url = Alias.get("sqlline@/sqlline");
+		assertThat(url.catalog.catalogRef.getOriginalResource(),
+				Matchers.equalTo("https://github.com/jbangapp/sqlline/blob/HEAD/jbang-catalog.json"));
+	}
 
+	@Test
+	public void testImplictURLAlias() {
 		Alias url = Alias.get("[email protected]");
 		assertThat(url.scriptRef, Matchers.equalTo("tree/main.java"));
-
 	}
 
 	@Test