Add workspace ignore list (#57)

* include ignored list from workspace

* used but workspace ignored should NOT give a warning

* remove unused default impl

* fix clippy warnings

Co-authored-by: Benjamin Bouvier <public@benj.me>

integration-tests/ignored-dep-workspace/Cargo.toml

@@ -0,0 +1,13 @@
+[workspace]
+members = ["./inner"]
+
+[workspace.dependencies]
+log = "0.4.14"
+serde = "1"
+
+[workspace.metadata.cargo-machete]
+ignored = [
+    "lazy_static",
+    "serde",
+    "futures", # actually used but in workspace ignored, should NOT cause a warning
+]

integration-tests/ignored-dep-workspace/inner/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "ignored-dep"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+log-once = "0.3.1"
+rand = "0.8.5"
+rand_core = "0.6.3"
+lazy_static = "1.4.0"
+serde.workspace = true
+futures = "0.3"
+
+[package.metadata.cargo-machete]
+ignored = [
+    "log",
+    "rand_core" # actually used, should cause a warning
+]

integration-tests/ignored-dep-workspace/inner/src/main.rs

@@ -0,0 +1,9 @@
+#[allow(unused_imports)]
+use rand_core::Error as _;
+
+#[allow(unused_imports)]
+use futures::Future as _;
+
+fn main() {
+    log_once::warn_once!("Hello, world!");
+}

src/main.rs

@@ -84,7 +84,7 @@ fn collect_paths(path: &Path, skip_target_dir: bool) -> Vec<PathBuf> {
         .filter_map(|entry| match entry {
             Ok(entry) if entry.file_name() == "Cargo.toml" => Some(entry.into_path()),
             Err(err) => {
-                eprintln!("error when walking over subdirectories: {}", err);
+                eprintln!("error when walking over subdirectories: {err}");
                 None
             }
             _ => None,
@@ -181,7 +181,7 @@ fn run_machete() -> anyhow::Result<bool> {
         for (analysis, path) in results {
             println!("{} -- {}:", analysis.package_name, path.to_string_lossy());
             for dep in &analysis.unused {
-                println!("\t{}", dep);
+                println!("\t{dep}");
                 has_unused_dependencies = true; // any unused dependency is enough to set flag to true
             }
 
@@ -214,7 +214,7 @@ fn remove_dependencies(manifest: &str, dependencies_list: &[String]) -> anyhow::
     for k in dependencies_list {
         dependencies
             .remove(k)
-            .with_context(|| format!("Dependency {} not found", k))?;
+            .with_context(|| format!("Dependency {k} not found"))?;
     }
 
     let serialized = manifest.to_string();