Fix formatting of channel factories

Signed-off-by: Ben Sherman <bentshermann@gmail.com>

Author: bentsherman

modules/nf-lang/src/main/java/nextflow/script/ast/ASTUtils.java

@@ -21,6 +21,8 @@
 import java.util.Optional;
 import java.util.stream.Stream;
 
+import nextflow.script.dsl.DslScope;
+import nextflow.script.dsl.Namespace;
 import org.codehaus.groovy.ast.ClassHelper;
 import org.codehaus.groovy.ast.ClassNode;
 import org.codehaus.groovy.ast.AnnotatedNode;
@@ -179,4 +181,25 @@ public static Optional<AnnotationNode> findAnnotation(AnnotatedNode node, Class
             .filter(an -> an.getClassNode().getName().equals(type.getName()))
             .findFirst();
     }
+
+    /**
+     * Determine whether a class is a DSL scope.
+     *
+     * @param cn
+     * @return
+     */
+    public static boolean isDslScope(ClassNode cn) {
+        return cn.implementsInterface(ClassHelper.makeCached(DslScope.class));
+    }
+
+    /**
+     * Determine whether a class is a namespace.
+     *
+     * @param cn
+     * @return
+     */
+    public static boolean isNamespace(ClassNode cn) {
+        return cn.implementsInterface(ClassHelper.makeCached(Namespace.class));
+    }
+
 }

modules/nf-lang/src/main/java/nextflow/script/formatter/Formatter.java

@@ -284,7 +284,7 @@ public void visitMethodCallExpression(MethodCallExpression node) {
             visit(receiver);
             if( inWrappedMethodChain ) {
                 incIndent();
-                if( !(receiver instanceof ClassExpression) ) {
+                if( !isNamespace(receiver.getType()) ) {
                     appendNewLine();
                     appendIndent();
                 }

modules/nf-lang/src/test/groovy/nextflow/script/formatter/ScriptFormatterTest.groovy

@@ -341,11 +341,11 @@ class ScriptFormatterTest extends Specification {
         expect:
         checkFormat(
             '''\
-            Channel.of( 1, 2, 3 )
+            channel.of( 1, 2, 3 )
                 .multiMap{v->foo:bar:v}.set{result}
             ''',
             '''\
-            Channel.of(1, 2, 3)
+            channel.of(1, 2, 3)
                 .multiMap { v -> foo: bar: v }
                 .set { result }
             '''