Extract Dependency - Add Ability To Add Dependencies

Dependencies can now be added to Extracts via the add_dependency()
method.

Working: #14

Author: OpenDataAlex

process_tracker/extract_tracker.py

@@ -110,6 +110,36 @@ def __init__(
 
         self.session.commit()
 
+    def add_dependency(self, dependency_type, dependency):
+        """
+        Add a parent or child dependency on the given extract file.
+        :param dependency_type: dependency type.  Valid values:  parent, child
+        :type dependency_type: string
+        :param dependency: dependent extract
+        :type dependency: SQLAlchemy Extract object
+        :return:
+        """
+
+        if dependency_type == "parent":
+            dependency = ExtractDependency(
+                child_extract_id=self.extract.extract_id,
+                parent_extract_id=dependency.extract.extract_id,
+            )
+
+        elif dependency_type == "child":
+            dependency = ExtractDependency(
+                child_extract_id=dependency.extract.extract_id,
+                parent_extract_id=self.extract.extract_id,
+            )
+        else:
+            self.logger.error("Invalid dependency type.")
+            raise Exception("Invalid extract dependency type.")
+
+        self.session.add(dependency)
+        self.session.commit()
+
+        self.logger.info("Extract %s dependency added." % dependency_type)
+
     def change_extract_status(self, new_status):
         """
         Change an extract record status.

tests/test_extract_tracker.py

@@ -70,6 +70,60 @@ def tearDown(self):
         self.session.query(Location).delete()
         self.session.commit()
 
+    def test_add_dependency_parent(self):
+        """
+        Testing that a parent extract dependency is created when adding dependency to extract.
+        :return:
+        """
+        dependent_extract = ExtractTracker(
+            process_run=self.process_run,
+            filename="Dependent File.csv",
+            location_name="Test Location",
+            location_path="/home/test/extract_dir",
+        )
+        self.extract.add_dependency(
+            dependency_type="parent", dependency=dependent_extract
+        )
+
+        given_result = (
+            self.session.query(ExtractDependency)
+            .filter(
+                ExtractDependency.child_extract_id == self.extract.extract.extract_id
+            )
+            .count()
+        )
+
+        expected_result = 1
+
+        self.assertEqual(expected_result, given_result)
+
+    def test_add_dependency_child(self):
+        """
+        Testing that a child extract dependency is created when adding dependency to extract.
+        :return:
+        """
+        dependent_extract = ExtractTracker(
+            process_run=self.process_run,
+            filename="Dependent File.csv",
+            location_name="Test Location",
+            location_path="/home/test/extract_dir",
+        )
+        self.extract.add_dependency(
+            dependency_type="child", dependency=dependent_extract
+        )
+
+        given_result = (
+            self.session.query(ExtractDependency)
+            .filter(
+                ExtractDependency.parent_extract_id == self.extract.extract.extract_id
+            )
+            .count()
+        )
+
+        expected_result = 1
+
+        self.assertEqual(expected_result, given_result)
+
     def test_initialization_no_location_no_location_path(self):
         """
         Testing that if no location or location path is set, an error is thrown.