Add integration tests regarding environment

This covers what was included in #6800

Signed-off-by: Ulysses Souza <ulysses.souza@docker.com>

tests/acceptance/cli_test.py

@@ -64,6 +64,12 @@ def wait_on_process(proc, returncode=0):
     return ProcessResult(stdout.decode('utf-8'), stderr.decode('utf-8'))
 
 
+def dispatch(base_dir, options, project_options=None, returncode=0):
+    project_options = project_options or []
+    proc = start_process(base_dir, project_options + options)
+    return wait_on_process(proc, returncode=returncode)
+
+
 def wait_on_condition(condition, delay=0.1, timeout=40):
     start_time = time.time()
     while not condition():
@@ -151,9 +157,7 @@ class CLITestCase(DockerClientTestCase):
         return self._project
 
     def dispatch(self, options, project_options=None, returncode=0):
-        project_options = project_options or []
-        proc = start_process(self.base_dir, project_options + options)
-        return wait_on_process(proc, returncode=returncode)
+        return dispatch(self.base_dir, options, project_options, returncode)
 
     def execute(self, container, cmd):
         # Remove once Hijack and CloseNotifier sign a peace treaty

tests/fixtures/env-file-override/.env.conf

@@ -0,0 +1,2 @@
+WHEREAMI
+DEFAULT_CONF_LOADED=true

tests/fixtures/env-file-override/.env.override

@@ -0,0 +1 @@
+WHEREAMI=override

tests/fixtures/env-file-override/docker-compose.yml

@@ -0,0 +1,6 @@
+version: '3.7'
+services:
+  test:
+    image: busybox
+    env_file: .env.conf
+    entrypoint: env

tests/integration/environment_test.py

@@ -7,7 +7,10 @@ from ddt import data
 from ddt import ddt
 
 from .. import mock
+from ..acceptance.cli_test import dispatch
+from compose.cli.command import get_project
 from compose.cli.command import project_from_options
+from compose.config.environment import Environment
 from tests.integration.testcases import DockerClientTestCase
 
 
@@ -50,3 +53,18 @@ services:
             # So no need to have a proper options map, the `COMMAND` key is enough
             project_from_options('.', options)
             assert fake_log.warn.call_count == 0
+
+
+class EnvironmentOverrideFileTest(DockerClientTestCase):
+    def test_env_file_override(self):
+        base_dir = 'tests/fixtures/env-file-override'
+        dispatch(base_dir, ['--env-file', '.env.override', 'up'])
+        project = get_project(project_dir=base_dir,
+                              config_path=['docker-compose.yml'],
+                              environment=Environment.from_env_file(base_dir, '.env.override'),
+                              override_dir=base_dir)
+        containers = project.containers(stopped=True)
+        assert len(containers) == 1
+        assert "WHEREAMI=override" in containers[0].get('Config.Env')
+        assert "DEFAULT_CONF_LOADED=true" in containers[0].get('Config.Env')
+        dispatch(base_dir, ['--env-file', '.env.override', 'down'], None)