@Test
    @Order(3)
    void basicMultipleUploadFileLimit(Page page) {
        // Arrange
        FileUpload fileUpload = page.fileupload;
        assertEquals("", fileUpload.getValue());

        // Act
        File file1 = locateClientSideFile("file1.csv");
        File file2 = locateClientSideFile("file2.csv");
        File file3 = locateClientSideFile("file3.csv");
        fileUpload.setValue(file1, file2, file3);

        page.button.click();
        wait4EmptyMesssage(page.uploadedFiles);

        // Assert
        assertNoJavascriptErrors();
        assertFalse(page.messages.getAllMessages().isEmpty());
        assertEquals("Maximum number of files exceeded.",
                page.messages.getMessage(0).getSummary());
        // Primefaces sends "empty" request if mode=simple skinSimple=true
        assertUploadedFiles(page.uploadedFiles);
        assertConfiguration(fileUpload);
    }
Tests basic multiple file upload.
p:fileUpload mode=simple auto=false multiple=true (skinSimple=true)
primefaces-integration-tests/src/test/java/org/primefaces/integrationtests/fileupload/FileUpload002Test.java