test/integration: Test top-level name interpolation

Refs #1319

Signed-off-by: Jonathan Sling <slingjonathan@gmail.com>

Author: Ramdek

tests/integration/env_tests/container-compose.yml

@@ -1,6 +1,6 @@
 version: "3"
 
-name: my-project-name
+name: my-project-name${ZZVAR1:-}
 
 services:
   env-test:

tests/integration/env_tests/test_podman_compose_env.py

@@ -87,3 +87,23 @@ def test_project_name_override(self) -> None:
                 compose_yaml_path(),
                 "down",
             ])
+
+    def test_project_name_interpolation(self) -> None:
+        try:
+            output, _ = self.run_subprocess_assert_returncode([
+                podman_compose_path(),
+                "-f",
+                compose_yaml_path(),
+                "run",
+                "-e",
+                "ZZVAR1=-myval2",
+                "project-name-test",
+            ])
+            self.assertIn("my-project-name-myval2", str(output))
+        finally:
+            self.run_subprocess_assert_returncode([
+                podman_compose_path(),
+                "-f",
+                compose_yaml_path(),
+                "down",
+            ])