From 526f77ea50c81371a23fc9732772d4b1bbc4b9a8 Mon Sep 17 00:00:00 2001
From: Wojciech Kozlowski <wk@wojciechkozlowski.eu>
Date: Sun, 14 Jan 2024 11:17:19 +0100
Subject: [PATCH] Fix code coverage

---
 README.md  |  4 +++-
 src/lib.rs | 41 +++++++++++++++++++++++++++++++++--------
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index f0d1207..29444e9 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,9 @@ cargo install grcov
 
 ```sh
 env CARGO_TARGET_DIR=codecov \
-    cargo clean
+    rm -rf ./codecov/debug/{coverage,profraw}
+env CARGO_TARGET_DIR=codecov \
+    cargo clean -p musichoard
 env RUSTFLAGS="-C instrument-coverage" \
     LLVM_PROFILE_FILE="codecov/debug/profraw/musichoard-%p-%m.profraw" \
     CARGO_TARGET_DIR=codecov \
diff --git a/src/lib.rs b/src/lib.rs
index 6f9ba32..fdd2e4a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1905,7 +1905,11 @@ mod tests {
         expected.tracks.append(&mut right.tracks.clone());
         expected.tracks.sort_unstable();
 
-        let merged = left.clone().merge(right);
+        let merged = left.clone().merge(right.clone());
+        assert_eq!(expected, merged);
+
+        // Non-overlapping merge should be commutative.
+        let merged = right.clone().merge(left.clone());
         assert_eq!(expected, merged);
     }
 
@@ -1931,13 +1935,18 @@ mod tests {
         let left = COLLECTION[0].to_owned();
         let mut right = COLLECTION[1].to_owned();
         right.id = left.id.clone();
+        right.properties = ArtistProperties::default();
 
         let mut expected = left.clone();
         expected.properties = expected.properties.merge(right.clone().properties);
         expected.albums.append(&mut right.albums.clone());
         expected.albums.sort_unstable();
 
-        let merged = left.clone().merge(right);
+        let merged = left.clone().merge(right.clone());
+        assert_eq!(expected, merged);
+
+        // Non-overlapping merge should be commutative.
+        let merged = right.clone().merge(left.clone());
         assert_eq!(expected, merged);
     }
 
@@ -1969,8 +1978,13 @@ mod tests {
         let mut expected = COLLECTION.to_owned();
         expected.sort_unstable();
 
-        let mut merged = left;
-        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, right);
+        let mut merged = left.clone();
+        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, right.clone());
+        assert_eq!(expected, merged);
+
+        // The merge is completele non-overlapping so it should be commutative.
+        let mut merged = right.clone();
+        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, left.clone());
         assert_eq!(expected, merged);
     }
 
@@ -1984,8 +1998,13 @@ mod tests {
         let mut expected = COLLECTION.to_owned();
         expected.sort_unstable();
 
-        let mut merged = left;
-        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, right);
+        let mut merged = left.clone();
+        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, right.clone());
+        assert_eq!(expected, merged);
+
+        // The merge does not overwrite any data so it should be commutative.
+        let mut merged = right.clone();
+        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, left.clone());
         assert_eq!(expected, merged);
     }
 
@@ -2012,8 +2031,14 @@ mod tests {
         expected.last_mut().map(|a| a.sort = artist_sort.clone());
         expected.rotate_right(1);
 
-        let mut merged = left;
-        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, right);
+        let mut merged = left.clone();
+        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, right.clone());
+        assert_eq!(expected.len(), merged.len());
+        assert_eq!(expected, merged);
+
+        // The merge overwrites the sort data, but no data is erased so it should be commutative.
+        let mut merged = right.clone();
+        MusicHoard::<NoLibrary, NoDatabase>::merge_in_place(&mut merged, left.clone());
         assert_eq!(expected.len(), merged.len());
         assert_eq!(expected, merged);
     }