Fix missing test coverage found by cargo-mutants

[djmitche]

I heard about cargo-mutants a RustConf 2024, and thought I'd give it a go. It ran for about 2h and found the following. Maybe this is nonsense, but worth a look. It would run faster if I could convince it to only run the lib tests and not the integration tests.

• taskchampion/src/server/cloud/gcp.rs:131:23: replace > with == in ::compare_and_swap in 5.5s build + 24.1s test
• taskchampion/src/taskdb/snapshot.rs:31:9: replace ::expecting -> fmt::Result with Ok(Default::default()) in 5.6s build + 24.5s test
• taskchampion/src/storage/mod.rs:137:23: replace && with || in StorageTxn::is_empty in 5.2s build + 24.5s test
• taskchampion/src/server/cloud/gcp.rs:211:36: replace < with == in <impl Iterator for ObjectIterator<'a>>::next in 5.2s build + 24.8s test
• taskchampion/src/replica.rs:420:9: replace Replica::add_undo_point -> Result<()> with Ok(()) in 5.6s build + 32.2s test
• taskchampion/src/task/task.rs:244:9: replace Task::get_legacy_udas -> impl Iterator<Item =(&str, &str)>+'_ with ::std::iter::once(("xyzzy", "xyzzy")) in 5.4s build + 25.1s test
• taskchampion/src/task/task.rs:252:9: replace Task::get_modified -> Option with Some(Default::default()) in 5.3s build + 24.9s test
• taskchampion/src/server/sync/mod.rs:168:9: replace ::add_snapshot -> Result<()> with Ok(()) in 5.3s build + 29.0s test
• taskchampion/src/taskdb/sync.rs:121:46: replace == with != in sync in 5.2s build + 24.1s test
• taskchampion/src/server/cloud/gcp.rs:21:70: replace == with != in is_http_error in 5.2s build + 24.6s test
• taskchampion/src/task/tag.rs:28:9: replace Tag::is_synthetic -> bool with false in 5.3s build + 24.3s test
• taskchampion/src/task/task.rs:244:9: replace Task::get_legacy_udas -> impl Iterator<Item =(&str, &str)>+'_ with ::std::iter::once(("xyzzy", "")) in 8.7s build + 29.2s test
• taskchampion/src/storage/mod.rs:135:23: replace && with || in StorageTxn::is_empty in 4.7s build + 24.5s test
• taskchampion/src/server/sync/mod.rs:85:36: replace == with != in sealed_from_resp in 5.1s build + 24.3s test
• taskchampion/src/server/cloud/gcp.rs:88:12: delete ! in ::del in 4.5s build + 24.2s test
• taskchampion/src/storage/mod.rs:133:9: replace StorageTxn::is_empty -> Result with Ok(true) in 5.5s build + 24.1s test
• taskchampion/src/server/encryption.rs:164:44: replace + with * in Envelope<'a>::to_bytes in 5.2s build + 24.7s test
• taskchampion/src/server/cloud/server.rs:194:14: replace < with == in CloudServer::snapshot_urgency in 5.9s build + 24.6s test
• taskchampion/src/server/cloud/gcp.rs:63:9: replace ::get -> Result<Option<Vec>> with Ok(Some(vec![0])) in 4.8s build + 24.2s test
• taskchampion/src/server/cloud/gcp.rs:142:27: replace != with == in ::compare_and_swap in 5.1s build + 33.6s test
• taskchampion/src/server/cloud/gcp.rs:23:72: replace == with != in is_http_error in 5.8s build + 25.1s test
• taskchampion/src/server/encryption.rs:145:27: replace + with * in Envelope<'a>::from_bytes in 4.5s build + 24.0s test
• taskchampion/src/taskdb/mod.rs:157:9: replace TaskDb::commit_reversed_operations -> Result with Ok(false) in 5.8s build + 24.9s test
• taskchampion/src/utils.rs:37:9: replace ::as_ref -> &[u8] with Vec::leak(Vec::new()) in 5.3s build + 24.4s test
• taskchampion/src/server/cloud/gcp.rs:110:9: replace ::compare_and_swap -> Result with Ok(false) in 6.3s build + 24.6s test
• taskchampion/src/task/tag.rs:33:9: replace Tag::is_user -> bool with false in 5.4s build + 24.1s test
• taskchampion/src/task/task.rs:40:9: replace ::eq -> bool with true in 5.8s build + 24.0s test
• taskchampion/src/server/cloud/gcp.rs:19:5: replace is_http_error -> bool with false in 6.4s build + 24.3s test
• taskchampion/src/replica.rs:106:9: replace Replica::all_task_uuids -> Result<Vec> with Ok(vec![]) in 5.1s build + 24.5s test
• taskchampion/src/task/task.rs:321:9: replace Task::set_wait -> Result<()> with Ok(()) in 5.2s build + 24.3s test
• taskchampion/src/server/cloud/gcp.rs:214:37: replace += with *= in <impl Iterator for ObjectIterator<'a>>::next in 5.5s build + 24.5s test
• taskchampion/src/task/task.rs:244:9: replace Task::get_legacy_udas -> impl Iterator<Item =(&str, &str)>+'_ with ::std::iter::once(("", "xyzzy")) in 5.4s build + 24.8s test
• taskchampion/src/replica.rs:106:9: replace Replica::all_task_uuids -> Result<Vec> with Ok(vec![Default::default()]) in 5.3s build + 24.7s test
• taskchampion/src/server/cloud/gcp.rs:131:23: replace > with < in ::compare_and_swap in 5.5s build + 24.8s test
• taskchampion/src/server/cloud/gcp.rs:63:9: replace ::get -> Result<Option<Vec>> with Ok(None) in 4.7s build + 24.4s test
• taskchampion/src/server/cloud/gcp.rs:110:9: replace ::compare_and_swap -> Result with Ok(true) in 5.4s build + 24.7s test
• taskchampion/src/task/task.rs:40:9: replace ::eq -> bool with false in 5.5s build + 24.2s test
• taskchampion/src/server/cloud/gcp.rs:204:9: replace <impl Iterator for ObjectIterator<'a>>::next -> OptionSelf::Item with None in 6.5s build + 24.4s test
• taskchampion/src/replica.rs:446:9: replace Replica::num_undo_points -> Result with Ok(1) in 5.1s build + 24.8s test
• taskchampion/src/utils.rs:37:9: replace ::as_ref -> &[u8] with Vec::leak(vec![0]) in 5.2s build + 24.6s test
• taskchampion/src/task/task.rs:244:9: replace Task::get_legacy_udas -> impl Iterator<Item =(&str, &str)>+'_ with ::std::iter::once(("", "")) in 6.2s build + 24.5s test
• taskchampion/src/replica.rs:355:12: delete ! in Replica::commit_reversed_operations in 5.3s build + 24.5s test
• taskchampion/src/server/cloud/server.rs:205:9: replace CloudServer::maybe_cleanup -> Result<()> with Ok(()) in 6.0s build + 24.4s test

[djmitche]

Looking through the rest of these, none are especially interesting or worth the time to investigate.