Distinguish initrd additions and removals

2 files changed, 34 insertions, 2 deletions

diff --git a/src/compare.rs b/src/compare.rs
index 7088886..8b59c1c 100644
--- a/src/compare.rs
+++ b/src/compare.rs
@@ -70,8 +70,13 @@ pub fn compare(left: &ArtifactManifest, right: &ArtifactManifest) -> ComparisonR
     compare_records(&left.files, &right.files, |record| &record.path, |path, change| {
         SemanticDifference::File { path: path.to_owned(), change }
     }, &mut differences);
-    if left.initrd != right.initrd {
-        differences.push(SemanticDifference::Initrd { change: Change::Changed });
+    match (&left.initrd, &right.initrd) {
+        (None, Some(_)) => differences.push(SemanticDifference::Initrd { change: Change::Added }),
+        (Some(_), None) => differences.push(SemanticDifference::Initrd { change: Change::Removed }),
+        (Some(left), Some(right)) if left != right => {
+            differences.push(SemanticDifference::Initrd { change: Change::Changed });
+        }
+        _ => {}
     }
     compare_records(&left.services, &right.services, |record| &record.name, |name, change| {
         SemanticDifference::Service { name: name.to_owned(), change }
diff --git a/tests/compare.rs b/tests/compare.rs
index 59b62cb..0853572 100644
--- a/tests/compare.rs
+++ b/tests/compare.rs
@@ -51,6 +51,33 @@ fn compares_added_removed_and_changed_semantic_records() {
 }
 
 #[test]
+fn distinguishes_added_and_removed_initrd_records() {
+    let without_initrd = ArtifactManifest::new(vec![], vec![], None, vec![], vec![])
+        .expect("valid manifest without initrd");
+    let with_initrd = ArtifactManifest::new(
+        vec![],
+        vec![],
+        Some(InitrdRecord::new("boot/initrd-rt.img", "digest")),
+        vec![],
+        vec![],
+    )
+    .expect("valid manifest with initrd");
+
+    assert_eq!(
+        compare(&without_initrd, &with_initrd).differences(),
+        &[SemanticDifference::Initrd {
+            change: Change::Added
+        }]
+    );
+    assert_eq!(
+        compare(&with_initrd, &without_initrd).differences(),
+        &[SemanticDifference::Initrd {
+            change: Change::Removed
+        }]
+    );
+}
+
+#[test]
 fn reads_and_writes_a_toml_manifest_beside_an_artifact() {
     let fixture = tempdir().expect("temporary directory");
     let artifact = fixture.path().join("controller.tar");