fix(testing): skip unpack for local imports

The generated test images contain WASM content but declare no rootfs
diff IDs. Running ctr's local unpack path is unnecessary and can leave
snapshot cleanup racing later stress tests, causing intermittent
"parent snapshot ... does not exist" failures.

Keep legacy ctr imports unchanged while retaining --local for versions
that require it.

Signed-off-by: HarnageaGabriel <gabriel.harnagea06@gmail.com>

Author: HarnageaGabriel

crates/containerd-shim-wasm/src/testing.rs

@@ -370,6 +370,16 @@ pub mod oci_helpers {
         pub media_type: String,
     }
 
+    fn add_import_flags(command: &mut Command, use_local: bool) {
+        if use_local {
+            // The generated image config has no rootfs diff IDs, so these
+            // tests only need the image and its content. Avoid creating local
+            // snapshots whose asynchronous cleanup can race later tests.
+            command.arg("--local").arg("--no-unpack");
+        }
+        command.arg("--all-platforms");
+    }
+
     pub fn import_image(
         image_name: &str,
         wasm_content: &[&ImageContent],
@@ -424,15 +434,8 @@ pub mod oci_helpers {
             .arg(TEST_NAMESPACE)
             .arg("image")
             .arg("import");
-        if use_local {
-            command.arg("--local");
-        }
-        let success = command
-            .arg("--all-platforms")
-            .arg(img_path)
-            .spawn()?
-            .wait()?
-            .success();
+        add_import_flags(&mut command, use_local);
+        let success = command.arg(img_path).spawn()?.wait()?.success();
         if !success {
             // if the container still exists try cleaning it up
             bail!(" failed to import image");
@@ -611,4 +614,35 @@ pub mod oci_helpers {
 
         Ok(())
     }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        #[test]
+        fn local_import_does_not_unpack() {
+            let mut command = Command::new("ctr");
+
+            add_import_flags(&mut command, true);
+
+            let args: Vec<_> = command
+                .get_args()
+                .map(|arg| arg.to_str().unwrap())
+                .collect();
+            assert_eq!(args, ["--local", "--no-unpack", "--all-platforms"]);
+        }
+
+        #[test]
+        fn legacy_import_keeps_compatible_flags() {
+            let mut command = Command::new("ctr");
+
+            add_import_flags(&mut command, false);
+
+            let args: Vec<_> = command
+                .get_args()
+                .map(|arg| arg.to_str().unwrap())
+                .collect();
+            assert_eq!(args, ["--all-platforms"]);
+        }
+    }
 }