[Bug] Integration tests that move files can fail when run in parallel

[kwigley]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Tests that move files in order to recreate user behavior modify python source code which can lead to failures when running tests in parallel.

Example of workflow failing: https://github.com/dbt-labs/dbt-core/runs/3887780692?check_suite_focus=true#step:9:1350
Example of test that moves files:

dbt-core/test/integration/068_partial_parsing_tests/test_partial_parsing.py

Lines 26 to 215 in fd7c95d

	def test_postgres_pp_models(self):
	# initial run
	self.run_dbt(['clean'])
	results = self.run_dbt(["run"])
	self.assertEqual(len(results), 1)
	# add a model file
	shutil.copyfile('extra-files/model_two.sql', 'models-a/model_two.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 2)
	# add a schema file
	shutil.copyfile('extra-files/models-schema1.yml', 'models-a/schema.yml')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 2)
	manifest = get_manifest()
	self.assertIn('model.test.model_one', manifest.nodes)
	model_one_node = manifest.nodes['model.test.model_one']
	self.assertEqual(model_one_node.description, 'The first model')
	self.assertEqual(model_one_node.patch_path, 'test://' + normalize('models-a/schema.yml'))
	# add a model and a schema file (with a test) at the same time
	shutil.copyfile('extra-files/models-schema2.yml', 'models-a/schema.yml')
	shutil.copyfile('extra-files/model_three.sql', 'models-a/model_three.sql')
	results = self.run_dbt(["--partial-parse", "test"], expect_pass=False)
	self.assertEqual(len(results), 1)
	manifest = get_manifest()
	project_files = [f for f in manifest.files if f.startswith('test://')]
	self.assertEqual(len(project_files), 4)
	model_3_file_id = 'test://' + normalize('models-a/model_three.sql')
	self.assertIn(model_3_file_id, manifest.files)
	model_three_file = manifest.files[model_3_file_id]
	self.assertEqual(model_three_file.parse_file_type, ParseFileType.Model)
	self.assertEqual(type(model_three_file).__name__, 'SourceFile')
	model_three_node = manifest.nodes[model_three_file.nodes[0]]
	schema_file_id = 'test://' + normalize('models-a/schema.yml')
	self.assertEqual(model_three_node.patch_path, schema_file_id)
	self.assertEqual(model_three_node.description, 'The third model')
	schema_file = manifest.files[schema_file_id]
	self.assertEqual(type(schema_file).__name__, 'SchemaSourceFile')
	self.assertEqual(len(schema_file.tests), 1)
	tests = schema_file.get_all_test_ids()
	self.assertEqual(tests, ['test.test.unique_model_three_id.6776ac8160'])
	unique_test_id = tests[0]
	self.assertIn(unique_test_id, manifest.nodes)
	# modify model sql file, ensure description still there
	shutil.copyfile('extra-files/model_three_modified.sql', 'models-a/model_three.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	manifest = get_manifest()
	model_id = 'model.test.model_three'
	self.assertIn(model_id, manifest.nodes)
	model_three_node = manifest.nodes[model_id]
	self.assertEqual(model_three_node.description, 'The third model')
	# Change the model 3 test from unique to not_null
	shutil.copyfile('extra-files/models-schema2b.yml', 'models-a/schema.yml')
	results = self.run_dbt(["--partial-parse", "test"], expect_pass=False)
	manifest = get_manifest()
	schema_file_id = 'test://' + normalize('models-a/schema.yml')
	schema_file = manifest.files[schema_file_id]
	tests = schema_file.get_all_test_ids()
	self.assertEqual(tests, ['test.test.not_null_model_three_id.3162ce0a6f'])
	not_null_test_id = tests[0]
	self.assertIn(not_null_test_id, manifest.nodes.keys())
	self.assertNotIn(unique_test_id, manifest.nodes.keys())
	self.assertEqual(len(results), 1)
	# go back to previous version of schema file, removing patch, test, and model for model three
	shutil.copyfile('extra-files/models-schema1.yml', 'models-a/schema.yml')
	os.remove(normalize('models-a/model_three.sql'))
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 2)
	# remove schema file, still have 3 models
	shutil.copyfile('extra-files/model_three.sql', 'models-a/model_three.sql')
	os.remove(normalize('models-a/schema.yml'))
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	manifest = get_manifest()
	schema_file_id = 'test://' + normalize('models-a/schema.yml')
	self.assertNotIn(schema_file_id, manifest.files)
	project_files = [f for f in manifest.files if f.startswith('test://')]
	self.assertEqual(len(project_files), 3)
	# Put schema file back and remove a model
	# referred to in schema file
	shutil.copyfile('extra-files/models-schema2.yml', 'models-a/schema.yml')
	os.remove(normalize('models-a/model_three.sql'))
	with self.assertRaises(CompilationException):
	results = self.run_dbt(["--partial-parse", "--warn-error", "run"])
	# Put model back again
	shutil.copyfile('extra-files/model_three.sql', 'models-a/model_three.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Add model four refing model three
	shutil.copyfile('extra-files/model_four1.sql', 'models-a/model_four.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 4)
	# Remove model_three and change model_four to ref model_one
	# and change schema file to remove model_three
	os.remove(normalize('models-a/model_three.sql'))
	shutil.copyfile('extra-files/model_four2.sql', 'models-a/model_four.sql')
	shutil.copyfile('extra-files/models-schema1.yml', 'models-a/schema.yml')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Remove model four, put back model three, put back schema file
	shutil.copyfile('extra-files/model_three.sql', 'models-a/model_three.sql')
	shutil.copyfile('extra-files/models-schema2.yml', 'models-a/schema.yml')
	os.remove(normalize('models-a/model_four.sql'))
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Add a macro
	shutil.copyfile('extra-files/my_macro.sql', 'macros/my_macro.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	manifest = get_manifest()
	macro_id = 'macro.test.do_something'
	self.assertIn(macro_id, manifest.macros)
	# Modify the macro
	shutil.copyfile('extra-files/my_macro2.sql', 'macros/my_macro.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Add a macro patch
	shutil.copyfile('extra-files/models-schema3.yml', 'models-a/schema.yml')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Remove the macro
	os.remove(normalize('macros/my_macro.sql'))
	with self.assertRaises(CompilationException):
	results = self.run_dbt(["--partial-parse", "--warn-error", "run"])
	# put back macro file, got back to schema file with no macro
	# add separate macro patch schema file
	shutil.copyfile('extra-files/models-schema2.yml', 'models-a/schema.yml')
	shutil.copyfile('extra-files/my_macro.sql', 'macros/my_macro.sql')
	shutil.copyfile('extra-files/macros.yml', 'macros/macros.yml')
	results = self.run_dbt(["--partial-parse", "run"])
	# delete macro and schema file
	print(f"\n\n*** remove macro and macro_patch\n\n")
	os.remove(normalize('macros/my_macro.sql'))
	os.remove(normalize('macros/macros.yml'))
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Add an empty schema file
	shutil.copyfile('extra-files/empty_schema.yml', 'models-a/eschema.yml')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Add version to empty schema file
	shutil.copyfile('extra-files/empty_schema_with_version.yml', 'models-a/eschema.yml')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	# Disable model_three
	shutil.copyfile('extra-files/model_three_disabled.sql', 'models-a/model_three.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 2)
	manifest = get_manifest()
	model_id = 'model.test.model_three'
	self.assertIn(model_id, manifest.disabled)
	self.assertNotIn(model_id, manifest.nodes)
	# Edit disabled model three
	shutil.copyfile('extra-files/model_three_disabled2.sql', 'models-a/model_three.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 2)
	manifest = get_manifest()
	model_id = 'model.test.model_three'
	self.assertIn(model_id, manifest.disabled)
	self.assertNotIn(model_id, manifest.nodes)
	# Remove disabled from model three
	shutil.copyfile('extra-files/model_three.sql', 'models-a/model_three.sql')
	results = self.run_dbt(["--partial-parse", "run"])
	self.assertEqual(len(results), 3)
	manifest = get_manifest()
	model_id = 'model.test.model_three'
	self.assertIn(model_id, manifest.nodes)
	self.assertNotIn(model_id, manifest.disabled)

Expected Behavior

Tests should be able to run in parallel.

Steps To Reproduce

I've been able to reproduce by running test in parallel locally. Something like:

python -m pytest -n12 -m profile_postgres test/integration

Relevant log output

No response

Environment

No response

What database are you using dbt with?

No response

Additional Context

No response

[kwigley]

A test's lifecycle looks something along the lines of:

• create a temp dir
• cd to this temp dir
• symlink everything in the test module directory of the current test being run to this temp dir (ex: everything in test/integration/068_partial_parsing_tests)
• write dbt_project.yml , profile, and other project files to this temp dir
• run the test (still in the temp dir)
• clean up the temp dir

Here is an example of a possible solution: https://github.com/dbt-labs/dbt-core/compare/refactor-partial-parsing-tests

This solution copies and deletes files in a directory in the temp dir that is not symlinked back to the source code. This is still not ideal, I want to use this opportunity to try out a better approach to protect from ending up in this scenario in the future.