diff --git a/src/main/java/rife/bld/extension/TestNgOperation.java b/src/main/java/rife/bld/extension/TestNgOperation.java
index ec567c9..49c9b5b 100644
--- a/src/main/java/rife/bld/extension/TestNgOperation.java
+++ b/src/main/java/rife/bld/extension/TestNgOperation.java
@@ -98,12 +98,24 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
 
     /**
      * The list of groups you want to be excluded from this run.
+     *
+     * @see #excludeGroups(Collection)
      */
     public TestNgOperation excludeGroups(String... group) {
         options.put("-excludegroups", String.join(",", group));
         return this;
     }
 
+    /**
+     * The list of groups you want to be excluded from this run.
+     *
+     * @see #excludeGroups(String...)
+     */
+    public TestNgOperation excludeGroups(Collection<String> group) {
+        options.put("-excludegroups", String.join(",", group));
+        return this;
+    }
+
     /**
      * Part of the {@link #execute execute} operation, constructs the command list to use for building the process.
      */
@@ -119,7 +131,7 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
             options.put("d", Path.of(project.buildDirectory().getPath(), "test-output").toString());
         }
 
-        List<String> args = new ArrayList<>();
+        final List<String> args = new ArrayList<>();
         args.add(javaTool());
 
         args.add("-cp");
@@ -197,12 +209,26 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
      * The list of groups you want to run.
      *
      * <p>For example: {@code "windows", "linux", "regression}</p>
+     *
+     * @see #groups(Collection)
      */
     public TestNgOperation groups(String... group) {
         options.put("-groups", String.join(",", group));
         return this;
     }
 
+    /**
+     * The list of groups you want to run.
+     *
+     * <p>For example: {@code "windows", "linux", "regression}</p>
+     *
+     * @see #groups(String...)
+     */
+    public TestNgOperation groups(Collection<String> group) {
+        options.put("-groups", String.join(",", group));
+        return this;
+    }
+
     /**
      * Ignore missed test names given by {@link #testNames(String...) testNames} and continue to run existing tests,
      * if any.
@@ -237,12 +263,25 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
     /**
      * The list of {@code .class} files or list of class names implementing {@code ITestListener} or
      * {@code ISuiteListener}
+     *
+     * @see #listener(Collection)
      */
     public TestNgOperation listener(String... listener) {
         options.put("-listener", String.join(",", listener));
         return this;
     }
 
+    /**
+     * The list of {@code .class} files or list of class names implementing {@code ITestListener} or
+     * {@code ISuiteListener}
+     *
+     * @see #listener(String...)
+     */
+    public TestNgOperation listener(Collection<String> listener) {
+        options.put("-listener", String.join(",", listener));
+        return this;
+    }
+
     /**
      * Set the Level of verbosity.
      *
@@ -257,22 +296,50 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
      * Specifies the list of {@code .class} files or class names implementing {@code IMethodSelector}.
      *
      * <p>For example: {@code "com.example.Selector1:3", "com.example.Selector2:2"}</p>
+     *
+     * @see #methodSelectors(Collection)
      */
     public TestNgOperation methodSelectors(String... selector) {
         options.put("-methodselectors", String.join(",", selector));
         return this;
     }
 
+    /**
+     * Specifies the list of {@code .class} files or class names implementing {@code IMethodSelector}.
+     *
+     * <p>For example: {@code "com.example.Selector1:3", "com.example.Selector2:2"}</p>
+     *
+     * @see #methodSelectors(String...)
+     */
+    public TestNgOperation methodSelectors(Collection<String> selector) {
+        options.put("-methodselectors", String.join(",", selector));
+        return this;
+    }
+
     /**
      * Lets you specify individual methods to run.
      *
      * <p>For example: {@code "com.example.Foo.f1", "com.example.Bar.f2"}</p>
+     *
+     * @see #methods(Collection)
      */
     public TestNgOperation methods(String... method) {
         options.put("-methods", String.join(",", method));
         return this;
     }
 
+    /**
+     * Lets you specify individual methods to run.
+     *
+     * <p>For example: {@code "com.example.Foo.f1", "com.example.Bar.f2"}</p>
+     *
+     * @see #methods(String...)
+     */
+    public TestNgOperation methods(Collection<String> method) {
+        options.put("-methods", String.join(",", method));
+        return this;
+    }
+
     /**
      * Mixed mode autodetects the type of current test and run it with appropriate runner.
      *
@@ -285,33 +352,74 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
 
     /**
      * The list of {@code .class} files or class names implementing {@code ITestRunnerFactory}.
+     * 
+     * @see #objectFactory(Collection) 
      */
     public TestNgOperation objectFactory(String... factory) {
         options.put("-objectfactory", String.join(",", factory));
         return this;
     }
 
+    /**
+     * The list of {@code .class} files or class names implementing {@code ITestRunnerFactory}.
+     *
+     * @see #objectFactory(String...) 
+     */
+    public TestNgOperation objectFactory(Collection<String> factory) {
+        options.put("-objectfactory", String.join(",", factory));
+        return this;
+    }
+
     /**
      * The list of fully qualified class names of listeners that should be skipped from being wired in via
      * Service Loaders.
+     *
+     * @see #overrideIncludedMethods(Collection)
      */
     public TestNgOperation overrideIncludedMethods(String... method) {
         options.put("-overrideincludedmethods", String.join(",", method));
         return this;
     }
 
+    /**
+     * The list of fully qualified class names of listeners that should be skipped from being wired in via
+     * Service Loaders.
+     *
+     * @see #overrideIncludedMethods(String...)
+     */
+    public TestNgOperation overrideIncludedMethods(Collection<String> method) {
+        options.put("-overrideincludedmethods", String.join(",", method));
+        return this;
+    }
+
     /**
      * The list of packages to include in this test.
      * If the package name ends with .* then subpackages are included too.
      * Required if no {@link #suites(String... suites)} specified.
      *
      * <p>For example: {@code "com.example", "test.sample.*"}</p>
+     *
+     * @see #packages(Collection)
      */
     public TestNgOperation packages(String... name) {
         packages.addAll(Arrays.stream(name).toList());
         return this;
     }
 
+    /**
+     * The list of packages to include in this test.
+     * If the package name ends with .* then subpackages are included too.
+     * Required if no {@link #suites(String... suites)} specified.
+     *
+     * <p>For example: {@code "com.example", "test.sample.*"}</p>
+     *
+     * @see #packages(String...)
+     */
+    public TestNgOperation packages(Collection<String> name) {
+        packages.addAll(name);
+        return this;
+    }
+
     /**
      * If specified, sets the default mechanism used to determine how to use parallel threads when running tests.
      * If not set, default mechanism is not to use parallel threads at all.
@@ -354,21 +462,48 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
      * The directories where your javadoc annotated test sources are. This option is only necessary
      * if you are using javadoc type annotations. (e.g. {@code "src/test"} or
      * {@code "src/test/org/testng/eclipse-plugin", "src/test/org/testng/testng"}).
+     *
+     * @see #sourceDir(String...)
      */
     public TestNgOperation sourceDir(String... directory) {
         options.put("-sourcedir", String.join(";", directory));
         return this;
     }
 
+    /**
+     * The directories where your javadoc annotated test sources are. This option is only necessary
+     * if you are using javadoc type annotations. (e.g. {@code "src/test"} or
+     * {@code "src/test/org/testng/eclipse-plugin", "src/test/org/testng/testng"}).
+     *
+     * @see #sourceDir(String...)
+     */
+    public TestNgOperation sourceDir(Collection<String> directory) {
+        options.put("-sourcedir", String.join(";", directory));
+        return this;
+    }
+
     /**
      * Specifies the List of fully qualified class names of listeners that should be skipped from being wired in via
      * Service Loaders.
+     *
+     * @see #spiListenersToSkip(Collection)
      */
     public TestNgOperation spiListenersToSkip(String... listenerToSkip) {
         options.put("-spilistenerstoskip", String.join(",", listenerToSkip));
         return this;
     }
 
+    /**
+     * Specifies the List of fully qualified class names of listeners that should be skipped from being wired in via
+     * Service Loaders.
+     *
+     * @see #spiListenersToSkip(String...)
+     */
+    public TestNgOperation spiListenersToSkip(Collection<String> listenerToSkip) {
+        options.put("-spilistenerstoskip", String.join(",", listenerToSkip));
+        return this;
+    }
+
     /**
      * This specifies the default name of the test suite, if not specified in the suite definition file or source code.
      * This option is ignored if the {@code suite.xml} file or the source code specifies a different suite name.
@@ -391,12 +526,26 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
      * Specifies the suites to run.
      *
      * <p>For example: {@code "testng.xml", "testng2.xml"}</p>
+     *
+     * @see #suites(Collection)
      */
     public TestNgOperation suites(String... suite) {
         suites.addAll(Arrays.stream(suite).toList());
         return this;
     }
 
+    /**
+     * Specifies the suites to run.
+     *
+     * <p>For example: {@code "testng.xml", "testng2.xml"}</p>
+     *
+     * @see #suites(String...)
+     */
+    public TestNgOperation suites(Collection<String> suite) {
+        suites.addAll(suite);
+        return this;
+    }
+
     /**
      * Create a test file and delete it on exit.
      */
@@ -410,20 +559,46 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
      * Specifies the list of class files.
      *
      * <p>For example: {@code "org.foo.Test1","org.foo.test2"}</p>
+     *
+     * @see #testClass(Collection)
      */
     public TestNgOperation testClass(String... aClass) {
         options.put("-testclass", String.join(",", aClass));
         return this;
     }
 
+    /**
+     * Specifies the list of class files.
+     *
+     * <p>For example: {@code "org.foo.Test1","org.foo.test2"}</p>
+     *
+     * @see #testClass(String...)
+     */
+    public TestNgOperation testClass(Collection<String> aClass) {
+        options.put("-testclass", String.join(",", aClass));
+        return this;
+    }
+
     /**
      * Specifies the classpath entries used to run tests.
+     *
+     * @see #testClasspath(String...)
      */
     public TestNgOperation testClasspath(String... entry) {
         testClasspath.addAll(Arrays.stream(entry).toList());
         return this;
     }
 
+    /**
+     * Specifies the classpath entries used to run tests.
+     *
+     * @see #testClasspath(String...)
+     */
+    public TestNgOperation testClasspath(Collection<String> entry) {
+        testClasspath.addAll(entry);
+        return this;
+    }
+
     /**
      * Specifies a jar file that contains test classes. If a {@code testng.xml} file is found at the root of that
      * jar file, it will be used, otherwise, all the test classes found in this jar file will be considered test
@@ -445,12 +620,24 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
 
     /**
      * Only tests defined in a {@code <test>} tag matching one of these names will be run.
+     *
+     * @see #testNames(Collection)
      */
     public TestNgOperation testNames(String... name) {
         options.put("-testnames", Arrays.stream(name).map(s -> '"' + s + '"').collect(Collectors.joining(",")));
         return this;
     }
 
+    /**
+     * Only tests defined in a {@code <test>} tag matching one of these names will be run.
+     *
+     * @see #testName(String)
+     */
+    public TestNgOperation testNames(Collection<String> name) {
+        options.put("-testnames", name.stream().map(s -> '"' + s + '"').collect(Collectors.joining(",")));
+        return this;
+    }
+
     /**
      * Specifies the factory used to create tests.
      */
diff --git a/src/test/java/rife/bld/extension/TestNgOperationTest.java b/src/test/java/rife/bld/extension/TestNgOperationTest.java
index bf61aaa..6c56a69 100644
--- a/src/test/java/rife/bld/extension/TestNgOperationTest.java
+++ b/src/test/java/rife/bld/extension/TestNgOperationTest.java
@@ -20,6 +20,8 @@ import org.junit.jupiter.api.Test;
 import rife.bld.Project; // NOPMD
 import rife.bld.operations.exceptions.ExitStatusException;
 
+import java.util.List;
+
 import static org.assertj.core.api.Assertions.*;
 
 /**
@@ -46,6 +48,10 @@ class TestNgOperationTest {
     void testClass() {
         var op = new TestNgOperation().testClass(FOO, BAR);
         assertThat(op.options.get(TestNgOperation.TEST_CLASS_ARG)).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        new TestNgOperation().testClass(List.of(FOO, BAR));
+        assertThat(op.options.get(TestNgOperation.TEST_CLASS_ARG)).as("as list")
+                .isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
@@ -70,6 +76,9 @@ class TestNgOperationTest {
     void testExcludeGroups() {
         var op = new TestNgOperation().excludeGroups(FOO, BAR);
         assertThat(op.options.get("-excludegroups")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        op = new TestNgOperation().excludeGroups(List.of(FOO, BAR));
+        assertThat(op.options.get("-excludegroups")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
@@ -113,6 +122,14 @@ class TestNgOperationTest {
                         .log(2)
                         .execute())
                 .as("with run classpath").doesNotThrowAnyException();
+
+        assertThatCode(() ->
+                new TestNgOperation().fromProject(new Project())
+                        .suites("src/test/resources/testng3.xml")
+                        .testClasspath(List.of("lib/test/*", "build/main", "build/test"))
+                        .log(2)
+                        .execute())
+                .as("with run classpath as list").doesNotThrowAnyException();
     }
 
     @Test
@@ -185,18 +202,27 @@ class TestNgOperationTest {
     void testListener() {
         var ops = new TestNgOperation().listener(FOO, BAR);
         assertThat(ops.options.get("-listener")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        ops = new TestNgOperation().listener(List.of(FOO, BAR));
+        assertThat(ops.options.get("-listener")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
     void testMethodDetectors() {
         var op = new TestNgOperation().methodSelectors(FOO, BAR);
         assertThat(op.options.get("-methodselectors")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        op = new TestNgOperation().methodSelectors(List.of(FOO, BAR));
+        assertThat(op.options.get("-methodselectors")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
     void testMethods() {
         var op = new TestNgOperation().methods(FOO, BAR);
         assertThat(op.options.get("-methods")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        new TestNgOperation().methods(List.of(FOO, BAR));
+        assertThat(op.options.get("-methods")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
@@ -218,24 +244,36 @@ class TestNgOperationTest {
     void testNames() {
         var ops = new TestNgOperation().testNames(FOO, BAR);
         assertThat(ops.options.get("-testnames")).isEqualTo(String.format("\"%s\",\"%s\"", FOO, BAR));
+
+        new TestNgOperation().testNames(List.of(FOO, BAR));
+        assertThat(ops.options.get("-testnames")).as("as list").isEqualTo(String.format("\"%s\",\"%s\"", FOO, BAR));
     }
 
     @Test
     void testObjectFactory() {
         var ops = new TestNgOperation().objectFactory(FOO, BAR);
         assertThat(ops.options.get("-objectfactory")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        ops = new TestNgOperation().objectFactory(List.of(FOO, BAR));
+        assertThat(ops.options.get("-objectfactory")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
     void testOverrideIncludedMethods() {
         var ops = new TestNgOperation().overrideIncludedMethods(FOO, BAR);
         assertThat(ops.options.get("-overrideincludedmethods")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        ops = new TestNgOperation().overrideIncludedMethods(List.of(FOO, BAR));
+        assertThat(ops.options.get("-overrideincludedmethods")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
     void testPackages() {
         var op = new TestNgOperation().packages(FOO, BAR);
         assertThat(op.packages).contains(FOO).contains(BAR);
+
+        op = new TestNgOperation().packages(List.of(FOO, BAR));
+        assertThat(op.packages).as("as list").contains(FOO).contains(BAR);
     }
 
     @Test
@@ -281,12 +319,18 @@ class TestNgOperationTest {
     void testSourceDir() {
         var op = new TestNgOperation().sourceDir(FOO, BAR);
         assertThat(op.options.get("-sourcedir")).isEqualTo(String.format("%s;%s", FOO, BAR));
+
+        op = new TestNgOperation().sourceDir(List.of(FOO, BAR));
+        assertThat(op.options.get("-sourcedir")).as("as list").isEqualTo(String.format("%s;%s", FOO, BAR));
     }
 
     @Test
     void testSpiListenersToSkip() {
         var ops = new TestNgOperation().spiListenersToSkip(FOO, BAR);
         assertThat(ops.options.get("-spilistenerstoskip")).isEqualTo(String.format("%s,%s", FOO, BAR));
+
+        ops = new TestNgOperation().spiListenersToSkip(List.of(FOO, BAR));
+        assertThat(ops.options.get("-spilistenerstoskip")).as("as list").isEqualTo(String.format("%s,%s", FOO, BAR));
     }
 
     @Test
@@ -305,6 +349,9 @@ class TestNgOperationTest {
     void testSuites() {
         var op = new TestNgOperation().suites(FOO, BAR);
         assertThat(op.suites).contains(FOO).contains(BAR);
+
+        op = new TestNgOperation().suites(List.of(FOO, BAR));
+        assertThat(op.suites).as("as list").contains(FOO).contains(BAR);
     }
 
     @Test