@Test
    @Order(4)
    void basicSingleUploadAllowTypes(Page page) throws InterruptedException {
        // Arrange
        FileUpload fileUpload = page.fileupload;
        assertEquals("", fileUpload.getValue());

        // Act
        File file = locateClientSideFile("file1.png");
        fileUpload.setValue(file);
        assertTrue(fileUpload.getValue().contains(file.getName()));
        page.button.click();

        // Assert
        assertFalse(page.messages.getAllMessages().isEmpty());
        assertEquals("Invalid file type.",
                page.messages.getMessage(0).getSummary());
        assertNoJavascriptErrors();
        assertConfiguration(fileUpload);
    }
Tests basic single file upload.
p:fileUpload mode=simple auto=false multiple=false (skinSimple=false)
primefaces-integration-tests/src/test/java/org/primefaces/integrationtests/fileupload/FileUpload000Test.java