diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 0f9f25d..af5fa8c 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
-<phpunit backupGlobals="false" backupStaticAttributes="false" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false" syntaxCheck="false" bootstrap="tests/phpunit/bootstrap.php">
+<phpunit backupGlobals="false" backupStaticAttributes="false" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="false" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false" syntaxCheck="false" bootstrap="tests/phpunit/bootstrap.php">
   <testsuites>
-    <testsuite name="My Test Suite">
+    <testsuite name="TwingleCampaign Suite">
       <directory>./tests/phpunit</directory>
     </testsuite>
   </testsuites>
diff --git a/tests/phpunit/CRM/TwingleCampaign/BAO/TwingleProjectTest.php b/tests/phpunit/CRM/TwingleCampaign/BAO/TwingleProjectTest.php
new file mode 100644
index 0000000..bf82a4b
--- /dev/null
+++ b/tests/phpunit/CRM/TwingleCampaign/BAO/TwingleProjectTest.php
@@ -0,0 +1,142 @@
+<?php
+
+use CRM_TwingleCampaign_ExtensionUtil as E;
+use Civi\Test\HeadlessInterface;
+use Civi\Test\HookInterface;
+use Civi\Test\TransactionalInterface;
+use CRM_TwingleCampaign_BAO_TwingleProject as TwingleProject;
+use \Civi\Test\Api3TestTrait;
+
+/**
+ * # Collection of tests for the TwingleProject class
+ *
+ * - tests the full TwingleProject circle (from Twingle to database to Twingle)
+ * - tests the input validation
+ *
+ * @group headless
+ */
+class CRM_TwingleCampaign_BAO_TwingleProjectTest extends \PHPUnit\Framework\TestCase implements HeadlessInterface, HookInterface, TransactionalInterface {
+
+  private $project;
+
+  private $dummyProject;
+  private $badDummyProject;
+
+  public function setUpHeadless() {
+    // Civi\Test has many helpers, like install(), uninstall(), sql(), and sqlFile().
+    // See: https://docs.civicrm.org/dev/en/latest/testing/phpunit/#civitest
+    return \Civi\Test::headless()
+      ->installMe(__DIR__)
+      ->apply();
+  }
+
+  /**
+   * @throws \Exception
+   */
+  public function setUp() {
+
+    // Create project from dummy values
+    $this->dummyProject =
+      require(E::path() . '/tests/resources/twingle_project_dummy.php');
+    $this->badDummyProject =
+      require(E::path() . '/tests/resources/twingle_project_bad_dummy.php');
+    $this->project = new TwingleProject($this->dummyProject);
+    $this->project->create(TRUE);
+
+    parent::setUp();
+  }
+
+  /**
+   * @throws \CiviCRM_API3_Exception
+   */
+  public function tearDown() {
+
+    // Delete project
+    $this->project->delete();
+    unset($this->project);
+
+    parent::tearDown();
+  }
+
+  /**
+   * ## The full TwingleProject circle
+   * This test simulates a TwingleProject that is fetched from the database and
+   * than gets instantiated and sent back to Twingle.
+   *
+   * It is important that all project values sent to the Twingle API have the
+   * same data types like when they were retrieved from Twingle. To test this,
+   * the export array will be compared to the original dummy array.
+   *
+   * dummy:array -> project:object -> database -> project:object -> export:array
+   *
+   * @throws \CiviCRM_API3_Exception
+   * @throws \Exception
+   */
+  public function testFullTwingleProjectCircle() {
+
+    // Get project via API from database
+    $project = civicrm_api3(
+      'TwingleProject',
+      'getsingle',
+      ['id' => $this->project->getId()]);
+    $project = new TwingleProject($project, $project['id']);
+
+    // Complement project values with dummy values. This is important because
+    // not all values coming from the Twingle API are stored in the database,
+    // but the Twingle API requires that all parameters are set.
+    $project->complement($this->dummyProject);
+
+    // Export project
+    $export = $project->export();
+
+    // Check if the project is sent to Twingle in the same state it arrived
+    $this->assertEquals(
+      $this->dummyProject,
+      $export,
+      'Export values differ from import values.'
+    );
+  }
+
+  /**
+   * ## Input validation
+   * Checks if the input validation works properly.
+   *
+   * @throws \CiviCRM_API3_Exception
+   * @throws \Exception
+   */
+  public function testInputValidation() {
+
+    // Get project via API from database
+    $project = civicrm_api3(
+      'TwingleProject',
+      'getsingle',
+      ['id' => $this->project->getId()]);
+    $project = new TwingleProject($project, $project['id']);
+
+    // Check if validation successes with healthy input
+    $validation_success = $project->validate();
+    $this->assertTrue(
+      $validation_success['valid'],
+      'Validation failed with healthy inputs.'
+    );
+
+    // Update project with values which simulate incorrect user input
+    $project->update($this->badDummyProject);
+
+    // Run validation again
+    $validation_fail = $project->validate();
+
+    // Check if validation failed (as it should)
+    $this->assertFalse(
+      $validation_fail['valid'],
+      'Validation did not fail as expected.'
+    );
+
+    // Check if all 6 wrong inputs were found
+    $this->assertCount(
+      6, $validation_fail['messages'],
+      'Did not find all 6 wrong inputs.'
+    );
+  }
+}
+
diff --git a/tests/resources/twingle_project_bad_dummy.php b/tests/resources/twingle_project_bad_dummy.php
new file mode 100644
index 0000000..a6aeda6
--- /dev/null
+++ b/tests/resources/twingle_project_bad_dummy.php
@@ -0,0 +1,136 @@
+<?php
+
+return  [
+  "id"               => 2243,
+  "internal_id"      => NULL,
+  "name"             => "TestProject",
+  "organisation_id"  => 555,
+  "slug"             => "test_project",
+  "identifier"       => "tw5555555555555",
+  "type"             => "event",
+  "transaction_type" => NULL,
+  "project_target"   => 1000,
+  "image_directory"  => NULL,
+  "allow_more"       => FALSE,
+  "last_update"      => 1614166801,
+  "embed"            => [
+    "page"                => "https://spenden.twingle.de/my-awesome-ngo/testprojekt/tw555555a555555c/page",
+    "eventpage"           => "https://my-awesome-ngo/event/testprojekt/tw555555a555555c/edit",
+    "widget"              => "<!-- twingle --><!-- twingle -->",
+    "form"                => "<!-- twingle --><!-- twingle -->",
+    "widget-single"       => "<!-- twingle --><!-- twingle -->",
+    "form-single"         => "<!-- twingle --><!-- twingle -->",
+    "eventall"            => "<!-- twingle --><!-- twingle -->",
+    "eventlist"           => "<!-- twingle --><!-- twingle -->",
+    "eventeditcreate"     => "<!-- twingle --><!-- twingle -->",
+    "giftdonationexample" => "https://spenden.twingle.de/gift/my-awesome-ngo/tw555555a555555c/example",
+    "letterexample"       => "https://spenden.twingle.de/letter/my-awesome-ngo/tw555555a555555c/example",
+  ],
+  "counter-url"      => [
+    "url" => "https://donationstatus.twingle.de/donation-status/555aaa",
+  ],
+  "host"             => "https://spenden.twingle.de/",
+  "project_options"  => [
+    "id"                                => 2237,
+    "has_confirmation_mail"             => FALSE,
+    "has_confirmation_mail_api"         => FALSE,
+    "has_donation_receipt"              => TRUE,
+    "has_contact_data"                  => FALSE,
+    "donation_rhythm"                   => [
+      "yearly"     => TRUE,
+      "halfyearly" => FALSE,
+      "quarterly"  => TRUE,
+      "monthly"    => TRUE,
+      "one_time"   => TRUE,
+    ],
+    "default_rhythm"                    => "",
+    "has_newsletter_registration"       => FALSE,
+    "has_postinfo_registration"         => FALSE,
+    "design_background_color"           => "not_a_hex", // not a hex
+    "design_primary_color"              => "green", // no hex either
+    "design_font"                       => "",
+    "design_font_color"                 => "true", // no hex either
+    "design_button_font_color"          => "",
+    "design_button_font_color_light"    => "",
+    "image"                             => "",
+    "bcc_email_address"                 => "mustermann@awesome", // no valid email
+    "donation_value_min"                => 50, // higher than max
+    "donation_value_max"                => 10,
+    "donation_value_default"            => 30, // higher than max, lower than min
+    "exclude_contact_fields"            => "company,birthday,telephone",
+    "mandatory_contact_fields"          => "firstname,lastname",
+    "custom_js"                         => NULL,
+    "custom_css"                        => "",
+    "share_url"                         => "not_a_url", // no valid url
+    "has_contact_mandatory"             => FALSE,
+    "has_doi"                           => TRUE,
+    "doi_redirect"                      => NULL,
+    "has_force_donation_target_buttons" => FALSE,
+    "has_show_single_target"            => FALSE,
+    "betterpayment_credit_card_theme"   => NULL,
+    "app_js"                            => NULL,
+    "slidericon"                        => "handshake",
+    "extra_field"                       => [],
+    "has_hidden_logo"                   => FALSE,
+    "has_projecttarget_as_money"        => FALSE,
+    "rapidmail_recipient_list"          => NULL,
+    "mailchimp_recipient_list"          => NULL,
+    "has_mailchimp_add_all_user"        => NULL,
+    "has_mail_hide_paymentblock"        => FALSE,
+    "has_mail_hide_paymentblock_api"    => FALSE,
+    "cleverreach_group_id"              => NULL,
+    "cleverreach_form_id"               => NULL,
+    "has_donationtarget_textfield"      => FALSE,
+    "has_civi_crm_activated"            => FALSE,
+    "has_step_index"                    => FALSE,
+    "gift_donation"                     => "",
+    "gift_donation_icon"                => NULL,
+    "gift_donation_image"               => NULL,
+    "languages"                         => "de",
+    "has_buttons"                       => FALSE,
+    "has_no_slider"                     => FALSE,
+    "buttons"                           => [
+      "button1" => [
+        "amount" => "5",
+      ],
+      "button2" => [
+        "amount" => "50",
+      ],
+      "button3" => [
+        "amount" => "100",
+      ],
+      "button4" => [
+        "amount" => "",
+      ],
+    ],
+    "has_newsletter_namerequest"        => FALSE,
+    "has_show_donator_data"             => FALSE,
+    "has_donation_letter"               => FALSE,
+    "has_donation_letter_api"           => FALSE,
+    "amount_images"                     => [],
+    "video_url"                         => NULL,
+  ],
+  "payment_methods"  => [
+    "has_paypal"                             => TRUE,
+    "has_betterpayment"                      => FALSE,
+    "has_sixpay"                             => FALSE,
+    "has_banktransfer"                       => TRUE,
+    "has_debit"                              => TRUE,
+    "has_sofortueberweisung"                 => FALSE,
+    "has_betterpayment_creditcard"           => FALSE,
+    "has_mbe4"                               => FALSE,
+    "has_generic"                            => FALSE,
+    "has_konfipay"                           => FALSE,
+    "has_konfipay_recurring"                 => FALSE,
+    "has_betterpayment_creditcard_recurring" => FALSE,
+    "has_paypal_recurring"                   => FALSE,
+    "has_debit_recurring"                    => TRUE,
+    "has_generic_recurring"                  => FALSE,
+    "has_sixpay_recurring"                   => FALSE,
+    "has_apple_pay"                          => FALSE,
+    "has_apple_pay_recurring"                => FALSE,
+    "has_paydirekt"                          => FALSE,
+    "has_paydirekt_recurring"                => FALSE,
+  ],
+];
+
diff --git a/tests/resources/twingle_project_dummy.php b/tests/resources/twingle_project_dummy.php
new file mode 100644
index 0000000..760f52b
--- /dev/null
+++ b/tests/resources/twingle_project_dummy.php
@@ -0,0 +1,137 @@
+<?php
+
+return  [
+  "id"               => 2243,
+  "internal_id"      => NULL,
+  "name"             => "TestProject",
+  "organisation_id"  => 555,
+  "slug"             => "test_project",
+  "identifier"       => "tw5555555555555",
+  "type"             => "event",
+  "transaction_type" => NULL,
+  "project_target"   => 1000,
+  "image_directory"  => NULL,
+  "allow_more"       => FALSE,
+  "last_update"      => 1614166801,
+  "embed"            => [
+    "page"                => "https://spenden.twingle.de/my-awesome-ngo/testprojekt/tw555555a555555c/page",
+    "eventpage"           => "https://my-awesome-ngo/event/testprojekt/tw555555a555555c/edit",
+    "widget"              => "<!-- twingle --><!-- twingle -->",
+    "form"                => "<!-- twingle --><!-- twingle -->",
+    "widget-single"       => "<!-- twingle --><!-- twingle -->",
+    "form-single"         => "<!-- twingle --><!-- twingle -->",
+    "eventall"            => "<!-- twingle --><!-- twingle -->",
+    "eventlist"           => "<!-- twingle --><!-- twingle -->",
+    "eventeditcreate"     => "<!-- twingle --><!-- twingle -->",
+    "giftdonationexample" => "https://spenden.twingle.de/gift/my-awesome-ngo/tw555555a555555c/example",
+    "letterexample"       => "https://spenden.twingle.de/letter/my-awesome-ngo/tw555555a555555c/example",
+  ],
+  "counter-url"      => [
+    "url" => "https://donationstatus.twingle.de/donation-status/555aaa",
+  ],
+  "host"             => "https://spenden.twingle.de/",
+  "project_options"  => [
+    "id"                                => 2237,
+    "has_confirmation_mail"             => FALSE,
+    "has_confirmation_mail_api"         => FALSE,
+    "has_donation_receipt"              => TRUE,
+    "has_contact_data"                  => FALSE,
+    "donation_rhythm"                   => [
+      "yearly"     => TRUE,
+      "halfyearly" => FALSE,
+      "quarterly"  => TRUE,
+      "monthly"    => TRUE,
+      "one_time"   => TRUE,
+    ],
+    "default_rhythm"                    => "",
+    "has_newsletter_registration"       => FALSE,
+    "has_postinfo_registration"         => FALSE,
+    "design_background_color"           => "ffffff",
+    "design_primary_color"              => "102045",
+    "design_font"                       => "",
+    "design_font_color"                 => "102045",
+    "design_button_font_color"          => "",
+    "design_button_font_color_light"    => "",
+    "image"                             => "",
+    "bcc_email_address"                 => "mustermann@awesome-ngo.org",
+    "donation_value_min"                => 5,
+    "donation_value_max"                => 1000,
+    "donation_value_default"            => 50,
+    "exclude_contact_fields"            => "company,birthday,telephone",
+    "mandatory_contact_fields"          => "firstname,lastname",
+    "custom_js"                         => NULL,
+    "custom_css"                        => "https://awesome-ngo.org/css",
+    "share_url"                         => "https://awesome-ngo.org/donate",
+    "has_contact_mandatory"             => FALSE,
+    "has_doi"                           => TRUE,
+    "doi_redirect"                      => NULL,
+    "has_force_donation_target_buttons" => FALSE,
+    "has_show_single_target"            => FALSE,
+    "betterpayment_credit_card_theme"   => NULL,
+    "app_js"                            => NULL,
+    "slidericon"                        => "handshake",
+    "extra_field"                       => [
+    ],
+    "has_hidden_logo"                   => FALSE,
+    "has_projecttarget_as_money"        => FALSE,
+    "rapidmail_recipient_list"          => NULL,
+    "mailchimp_recipient_list"          => NULL,
+    "has_mailchimp_add_all_user"        => NULL,
+    "has_mail_hide_paymentblock"        => FALSE,
+    "has_mail_hide_paymentblock_api"    => FALSE,
+    "cleverreach_group_id"              => NULL,
+    "cleverreach_form_id"               => NULL,
+    "has_donationtarget_textfield"      => FALSE,
+    "has_civi_crm_activated"            => FALSE,
+    "has_step_index"                    => FALSE,
+    "gift_donation"                     => "",
+    "gift_donation_icon"                => NULL,
+    "gift_donation_image"               => NULL,
+    "languages"                         => "de",
+    "has_buttons"                       => FALSE,
+    "has_no_slider"                     => FALSE,
+    "buttons"                           => [
+      "button1" => [
+        "amount" => "5",
+      ],
+      "button2" => [
+        "amount" => "50",
+      ],
+      "button3" => [
+        "amount" => "100",
+      ],
+      "button4" => [
+        "amount" => "",
+      ],
+    ],
+    "has_newsletter_namerequest"        => FALSE,
+    "has_show_donator_data"             => FALSE,
+    "has_donation_letter"               => FALSE,
+    "has_donation_letter_api"           => FALSE,
+    "amount_images"                     => [],
+    "video_url"                         => NULL,
+  ],
+  "payment_methods"  => [
+    "has_paypal"                             => TRUE,
+    "has_betterpayment"                      => FALSE,
+    "has_sixpay"                             => FALSE,
+    "has_banktransfer"                       => TRUE,
+    "has_debit"                              => TRUE,
+    "has_sofortueberweisung"                 => FALSE,
+    "has_betterpayment_creditcard"           => FALSE,
+    "has_mbe4"                               => FALSE,
+    "has_generic"                            => FALSE,
+    "has_konfipay"                           => FALSE,
+    "has_konfipay_recurring"                 => FALSE,
+    "has_betterpayment_creditcard_recurring" => FALSE,
+    "has_paypal_recurring"                   => FALSE,
+    "has_debit_recurring"                    => TRUE,
+    "has_generic_recurring"                  => FALSE,
+    "has_sixpay_recurring"                   => FALSE,
+    "has_apple_pay"                          => FALSE,
+    "has_apple_pay_recurring"                => FALSE,
+    "has_paydirekt"                          => FALSE,
+    "has_paydirekt_recurring"                => FALSE,
+  ],
+];
+