diff --git a/examples/flow.ipyg b/tests/assets/flow_test.ipyg
similarity index 99%
rename from examples/flow.ipyg
rename to tests/assets/flow_test.ipyg
index 9fce6f7a..414cfd1c 100644
--- a/examples/flow.ipyg
+++ b/tests/assets/flow_test.ipyg
@@ -268,7 +268,7 @@
                     }
                 }
             ],
-            "source": "b = 3",
+            "source": "b = 3\r\nb",
             "stdout": ""
         },
         {
@@ -749,7 +749,7 @@
                 }
             },
             "sockets": [],
-            "text": "**Test flow tests the general behavior of flow execution:**\r\n\r\n\tExecuting 6 left should output 4\r\n\r\n\tExecuting 6 right should output 21 in block 8\r\n"
+            "text": "**Test flow tests the general behavior of flow execution:**\r\n\r\n\tExecuting 6 left should output 6\r\n\r\n\tExecuting 6 right should output 21 in block 8\r\n"
         }
     ],
     "edges": [
diff --git a/tests/integration/blocks/test_flow.py b/tests/integration/blocks/test_flow.py
new file mode 100644
index 00000000..3e298b2d
--- /dev/null
+++ b/tests/integration/blocks/test_flow.py
@@ -0,0 +1,134 @@
+# OpenCodeBlock an open-source tool for modular visual programing in python
+# Copyright (C) 2021 Mathïs FEDERICO <https://www.gnu.org/licenses/>
+
+"""
+Integration tests for the execution flow.
+"""
+
+import pytest
+import time
+
+from opencodeblocks.blocks.codeblock import OCBCodeBlock
+from opencodeblocks.graphics.window import OCBWindow
+from opencodeblocks.graphics.widget import OCBWidget
+
+from tests.integration.utils import apply_function_inapp, CheckingQueue
+
+
+class TestExecutionFlow:
+    """Execution flow"""
+
+    @pytest.fixture(autouse=True)
+    def setup(self):
+        """Setup reused variables."""
+        self.window = OCBWindow()
+        self.ocb_widget = OCBWidget()
+        self.subwindow = self.window.mdiArea.addSubWindow(self.ocb_widget)
+        self.subwindow.show()
+
+        self.ocb_widget.scene.load("tests/assets/flow_test.ipyg")
+
+        self.titles = [
+            "Test flow 5",
+            "Test flow 4",
+            "Test flow 8",
+            "Test no connection 1",
+        ]
+        self.blocks_to_run = [None] * len(self.titles)
+        for item in self.ocb_widget.scene.items():
+            if isinstance(item, OCBCodeBlock):
+                if item.title in self.titles:
+                    self.blocks_to_run[self.titles.index(item.title)] = item
+
+    def test_flow_left(self):
+        """run block and previous blocks when pressing left run."""
+
+        def testing_run(msgQueue: CheckingQueue):
+
+            block_to_run: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test flow 5")
+            ]
+            block_to_not_run: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test flow 4")
+            ]
+
+            def run_block():
+                block_to_run.run_left()
+
+            # Run the execution in a separate thread
+            # to give time for the outputs to show before checking them
+            msgQueue.run_lambda(run_block)
+            time.sleep(0.5)
+
+            msgQueue.check_equal(block_to_run.stdout.strip(), "6")
+            msgQueue.check_equal(block_to_not_run.stdout.strip(), "")
+            msgQueue.stop()
+
+        apply_function_inapp(self.window, testing_run)
+
+    def test_flow_right(self):
+        """run block and next blocks when pressing right run."""
+
+        def testing_run(msgQueue: CheckingQueue):
+
+            block_to_run: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test flow 5")
+            ]
+            block_output: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test flow 8")
+            ]
+            block_to_not_run: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test flow 4")
+            ]
+
+            def run_block():
+                block_to_run.run_right()
+
+            msgQueue.run_lambda(run_block)
+            time.sleep(0.5)
+
+            msgQueue.check_equal(block_output.stdout.strip(), "21")
+            msgQueue.check_equal(block_to_not_run.stdout.strip(), "")
+            msgQueue.stop()
+
+        apply_function_inapp(self.window, testing_run)
+
+    def test_no_connection_left(self):
+        """run block only when no previous connection."""
+
+        def testing_run(msgQueue: CheckingQueue):
+
+            block_to_run: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test no connection 1")
+            ]
+
+            def run_block():
+                block_to_run.run_left()
+
+            msgQueue.run_lambda(run_block)
+            time.sleep(0.5)
+
+            msgQueue.check_equal(block_to_run.stdout.strip(), "1")
+            msgQueue.stop()
+
+        apply_function_inapp(self.window, testing_run)
+
+    def test_no_connection_right(self):
+        """run block only when no next connection."""
+
+        def testing_run(msgQueue: CheckingQueue):
+
+            block_to_run: OCBCodeBlock = self.blocks_to_run[
+                self.titles.index("Test no connection 1")
+            ]
+
+            def run_block():
+                block_to_run.run_right()
+
+            msgQueue.run_lambda(run_block)
+            time.sleep(0.5)
+
+            # Just check that it doesn't crash
+            msgQueue.stop()
+
+        apply_function_inapp(self.window, testing_run)
diff --git a/tests/integration/utils.py b/tests/integration/utils.py
index 810106d5..41d1ea44 100644
--- a/tests/integration/utils.py
+++ b/tests/integration/utils.py
@@ -18,12 +18,16 @@
 
 STOP_MSG = "stop"
 CHECK_MSG = "check"
+RUN_MSG = "run"
 
 
 class CheckingQueue(Queue):
     def check_equal(self, a, b, msg=""):
         self.put([CHECK_MSG, a, b, msg])
 
+    def run_lambda(self, func: Callable, *args, **kwargs):
+        self.put([RUN_MSG, func, args, kwargs])
+
     def stop(self):
         self.put([STOP_MSG])
 
@@ -47,5 +51,7 @@ def apply_function_inapp(window: OCBWindow, run_func: Callable):
                 check.equal(msg[1], msg[2], msg[3])
             elif msg[0] == STOP_MSG:
                 stop = True
+            elif msg[0] == RUN_MSG:
+                msg[1](*msg[2], **msg[3])
     t.join()
     window.close()