refactor(deps): use conflate instead of merge crate (#284)

conflate (essentially merge 0.1.0-dev) lacks the blanket `impl<T> Merge
for Option<T>`, which was removed from version 0.1.0

```rust
impl<T> Merge for Option<T> {
    fn merge(&mut self, mut other: Self) {
        if !self.is_some() {
            *self = other.take();
        }
    }
}
```

Hence, I added the `overwrite_none` strategies where needed.

We could also add it back, for a future version, though I think there
was some decision involved, that strategies should be more explicit,
because it could be confusing for strategies being applied without
having an annotation. So I felt, I don't want to add that back to
`conflate` for now.

Fixes #258

---------

Signed-off-by: simonsan <[email protected]>
Co-authored-by: Alexander Weiss <[email protected]>

README.md

@@ -50,7 +50,7 @@ This crate exposes a few features for controlling dependency usage:
 - **cli** - Enables support for CLI features by enabling `merge` and `clap`
   features. *This feature is disabled by default*.
 - **merge** - Enables support for merging multiple values into one, which
-  enables the `merge` dependency. This is needed for parsing commandline
+  enables the `conflate` dependency. This is needed for parsing commandline
   arguments and merging them into one (e.g. `config`). *This feature is disabled
   by default*.
 - **clap** - Enables a dependency on the `clap` crate and enables parsing from

crates/backend/Cargo.toml

@@ -33,7 +33,7 @@ edition = "2021"
 [features]
 default = ["opendal", "rest", "rclone"]
 cli = ["merge", "clap"]
-merge = ["dep:merge"]
+merge = ["dep:conflate"]
 clap = ["dep:clap"]
 opendal = ["dep:opendal", "dep:rayon", "dep:tokio", "tokio/rt-multi-thread"]
 rest = ["dep:reqwest", "dep:backoff"]
@@ -66,7 +66,7 @@ url = "2.5.2"
 
 # cli support
 clap = { version = "4.5.16", optional = true, features = ["derive", "env", "wrap_help"] }
-merge = { version = "0.1.0", optional = true }
+conflate = { version = "0.2.0", optional = true }
 
 # local backend
 aho-corasick = { workspace = true }

crates/backend/README.md

@@ -58,7 +58,7 @@ This crate exposes a few features for controlling dependency usage:
   the commandline. *This feature is disabled by default*.
 
 - **merge** - Enables support for merging multiple values into one, which
-  enables the `merge` dependency. This is needed for parsing commandline
+  enables the `conflate` dependency. This is needed for parsing commandline
   arguments and merging them into one (e.g. `config`). *This feature is disabled
   by default*.
 

crates/backend/src/choose.rs

@@ -27,7 +27,7 @@ use clap::ValueHint;
 
 /// Options for a backend.
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
-#[cfg_attr(feature = "merge", derive(merge::Merge))]
+#[cfg_attr(feature = "merge", derive(conflate::Merge))]
 #[derive(Clone, Default, Debug, serde::Deserialize, serde::Serialize, Setters)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 #[setters(into, strip_option)]
@@ -37,13 +37,15 @@ pub struct BackendOptions {
         feature = "clap",
         clap(short, long, global = true, visible_alias = "repo", env = "RUSTIC_REPOSITORY", value_hint = ValueHint::DirPath)
     )]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub repository: Option<String>,
 
     /// Repository to use as hot storage
     #[cfg_attr(
         feature = "clap",
         clap(long, global = true, alias = "repository_hot", env = "RUSTIC_REPO_HOT")
     )]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub repo_hot: Option<String>,
 
     /// Other options for this repository (hot and cold part)

crates/core/Cargo.toml

@@ -31,7 +31,7 @@ edition = "2021"
 [features]
 default = []
 cli = ["merge", "clap"]
-merge = ["dep:merge"]
+merge = ["dep:conflate"]
 clap = ["dep:clap"]
 webdav = ["dep:dav-server", "dep:futures"]
 
@@ -87,7 +87,7 @@ dirs = "5.0.1"
 
 # cli support
 clap = { version = "4.5.16", optional = true, features = ["derive", "env", "wrap_help"] }
-merge = { version = "0.1.0", optional = true }
+conflate = { version = "0.2.0", optional = true }
 
 # vfs support
 dav-server = { version = "0.7.0", default-features = false, optional = true }

crates/core/src/backend/ignore.rs

@@ -42,82 +42,83 @@ pub struct LocalSource {
 
 #[serde_as]
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
-#[cfg_attr(feature = "merge", derive(merge::Merge))]
+#[cfg_attr(feature = "merge", derive(conflate::Merge))]
 #[derive(serde::Deserialize, serde::Serialize, Default, Clone, Copy, Debug, Setters)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 #[setters(into)]
 /// [`LocalSourceSaveOptions`] describes how entries from a local source will be saved in the repository.
 pub struct LocalSourceSaveOptions {
     /// Save access time for files and directories
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub with_atime: bool,
 
     /// Don't save device ID for files and directories
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub ignore_devid: bool,
 }
 
 #[serde_as]
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
-#[cfg_attr(feature = "merge", derive(merge::Merge))]
+#[cfg_attr(feature = "merge", derive(conflate::Merge))]
 #[derive(serde::Deserialize, serde::Serialize, Default, Clone, Debug, Setters)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 #[setters(into)]
 /// [`LocalSourceFilterOptions`] allow to filter a local source by various criteria.
 pub struct LocalSourceFilterOptions {
     /// Glob pattern to exclude/include (can be specified multiple times)
     #[cfg_attr(feature = "clap", clap(long = "glob", value_name = "GLOB"))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::vec::overwrite_empty))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::vec::overwrite_empty))]
     pub globs: Vec<String>,
 
     /// Same as --glob pattern but ignores the casing of filenames
     #[cfg_attr(feature = "clap", clap(long = "iglob", value_name = "GLOB"))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::vec::overwrite_empty))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::vec::overwrite_empty))]
     pub iglobs: Vec<String>,
 
     /// Read glob patterns to exclude/include from this file (can be specified multiple times)
     #[cfg_attr(feature = "clap", clap(long = "glob-file", value_name = "FILE"))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::vec::overwrite_empty))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::vec::overwrite_empty))]
     pub glob_files: Vec<String>,
 
     /// Same as --glob-file ignores the casing of filenames in patterns
     #[cfg_attr(feature = "clap", clap(long = "iglob-file", value_name = "FILE"))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::vec::overwrite_empty))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::vec::overwrite_empty))]
     pub iglob_files: Vec<String>,
 
     /// Ignore files based on .gitignore files
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub git_ignore: bool,
 
     /// Do not require a git repository to apply git-ignore rule
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub no_require_git: bool,
 
     /// Treat the provided filename like a .gitignore file (can be specified multiple times)
     #[cfg_attr(
         feature = "clap",
         clap(long = "custom-ignorefile", value_name = "FILE")
     )]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::vec::overwrite_empty))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::vec::overwrite_empty))]
     pub custom_ignorefiles: Vec<String>,
 
     /// Exclude contents of directories containing this filename (can be specified multiple times)
     #[cfg_attr(feature = "clap", clap(long, value_name = "FILE"))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::vec::overwrite_empty))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::vec::overwrite_empty))]
     pub exclude_if_present: Vec<String>,
 
     /// Exclude other file systems, don't cross filesystem boundaries and subvolumes
     #[cfg_attr(feature = "clap", clap(long, short = 'x'))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub one_file_system: bool,
 
     /// Maximum size of files to be backed up. Larger files will be excluded.
     #[cfg_attr(feature = "clap", clap(long, value_name = "SIZE"))]
     #[serde_as(as = "Option<DisplayFromStr>")]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub exclude_larger_than: Option<ByteSize>,
 }
 

crates/core/src/commands/backup.rs

@@ -32,7 +32,7 @@ use clap::ValueHint;
 /// `backup` subcommand
 #[serde_as]
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
-#[cfg_attr(feature = "merge", derive(merge::Merge))]
+#[cfg_attr(feature = "merge", derive(conflate::Merge))]
 #[derive(Clone, Default, Debug, Deserialize, Serialize, Setters)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 #[setters(into)]
@@ -43,33 +43,35 @@ pub struct ParentOptions {
     /// Group snapshots by any combination of host,label,paths,tags to find a suitable parent (default: host,label,paths)
     #[cfg_attr(feature = "clap", clap(long, short = 'g', value_name = "CRITERION",))]
     #[serde_as(as = "Option<DisplayFromStr>")]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub group_by: Option<SnapshotGroupCriterion>,
 
     /// Snapshot to use as parent
     #[cfg_attr(
         feature = "clap",
         clap(long, value_name = "SNAPSHOT", conflicts_with = "force",)
     )]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub parent: Option<String>,
 
     /// Skip writing of snapshot if nothing changed w.r.t. the parent snapshot.
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub skip_identical_parent: bool,
 
     /// Use no parent, read all files
     #[cfg_attr(feature = "clap", clap(long, short, conflicts_with = "parent",))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub force: bool,
 
     /// Ignore ctime changes when checking for modified files
     #[cfg_attr(feature = "clap", clap(long, conflicts_with = "force",))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub ignore_ctime: bool,
 
     /// Ignore inode number changes when checking for modified files
     #[cfg_attr(feature = "clap", clap(long, conflicts_with = "force",))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub ignore_inode: bool,
 }
 
@@ -127,7 +129,7 @@ impl ParentOptions {
 }
 
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
-#[cfg_attr(feature = "merge", derive(merge::Merge))]
+#[cfg_attr(feature = "merge", derive(conflate::Merge))]
 #[derive(Clone, Default, Debug, Deserialize, Serialize, Setters)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 #[setters(into)]
@@ -144,20 +146,22 @@ pub struct BackupOptions {
 
     /// Call the given command and use its output as stdin
     #[cfg_attr(feature = "clap", clap(long, value_name = "COMMAND"))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub stdin_command: Option<CommandInput>,
 
     /// Manually set backup path in snapshot
     #[cfg_attr(feature = "clap", clap(long, value_name = "PATH", value_hint = ValueHint::DirPath))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::option::overwrite_none))]
     pub as_path: Option<PathBuf>,
 
     /// Don't scan the backup source for its size - this disables ETA estimation for backup.
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub no_scan: bool,
 
     /// Dry-run mode: Don't write any data or snapshot
     #[cfg_attr(feature = "clap", clap(long))]
-    #[cfg_attr(feature = "merge", merge(strategy = merge::bool::overwrite_false))]
+    #[cfg_attr(feature = "merge", merge(strategy = conflate::bool::overwrite_false))]
     pub dry_run: bool,
 
     #[cfg_attr(feature = "clap", clap(flatten))]