Add --depth option

src/cli.rs

@@ -1,4 +1,4 @@
-use clap::{Arg, ArgAction, Command};
+use clap::{value_parser, Arg, ArgAction, Command};
 
 pub(crate) struct Config {
     pub build_deps: bool,
@@ -10,8 +10,8 @@ pub(crate) struct Config {
     pub include: Vec<String>,
     pub root: Vec<String>,
     pub workspace_only: bool,
-    pub direct_dependencies_only: bool,
     pub focus: Vec<String>,
+    pub depth: Option<u32>,
 
     pub features: Vec<String>,
     pub all_features: bool,
@@ -109,12 +109,6 @@ pub(crate) fn parse_options() -> Config {
                         .action(ArgAction::SetTrue)
                         .help("Exclude all packages outside of the workspace"),
                 )
-                .arg(
-                    Arg::new("direct_dependencies_only")
-                        .long("direct-dependencies-only")
-                        .action(ArgAction::SetTrue)
-                        .help("Only list direct dependencies of workspace crates"),
-                )
                 .arg(
                     Arg::new("focus")
                         .long("focus")
@@ -127,6 +121,13 @@ pub(crate) fn parse_options() -> Config {
                              list or as multiple arguments",
                         ),
                 )
+                .arg(
+                    Arg::new("depth")
+                        .long("depth")
+                        .value_parser(value_parser!(u32))
+                        .action(ArgAction::Set)
+                        .help("Limit the depth of the dependency graph")
+                )
                 // Options to pass through to `cargo metadata`
                 .arg(
                     Arg::new("features")
@@ -205,8 +206,8 @@ pub(crate) fn parse_options() -> Config {
     let include = matches.get_many("include").map_or_else(Vec::new, collect_owned);
     let root = matches.get_many("root").map_or_else(Vec::new, collect_owned);
     let workspace_only = matches.get_flag("workspace_only");
-    let direct_dependencies_only = matches.get_flag("direct_dependencies_only");
     let focus = matches.get_many("focus").map_or_else(Vec::new, collect_owned);
+    let depth = matches.get_one("depth").cloned();
 
     let features = matches.get_many("features").map_or_else(Vec::new, collect_owned);
     let all_features = matches.get_flag("all_features");
@@ -228,8 +229,8 @@ pub(crate) fn parse_options() -> Config {
         include,
         root,
         workspace_only,
-        direct_dependencies_only,
         focus,
+        depth,
         features,
         all_features,
         no_default_features,

src/graph/build.rs

@@ -44,13 +44,13 @@ pub(crate) fn get_dep_graph(metadata: Metadata, config: &Config) -> anyhow::Resu
         }
 
         let node_idx = graph.add_node(Package::new(pkg, true));
-        deps_add_queue.push_back(pkg_id.clone());
+        deps_add_queue.push_back((pkg_id.clone(), 0u32));
         let old_val = node_indices.insert(pkg_id.clone(), node_idx);
         assert!(old_val.is_none());
     }
 
     // Add dependencies of the roots
-    while let Some(pkg_id) = deps_add_queue.pop_front() {
+    while let Some((pkg_id, depth)) = deps_add_queue.pop_front() {
         let pkg = get_package(&metadata.packages, &pkg_id);
 
         let parent_idx = *node_indices
@@ -88,6 +88,11 @@ pub(crate) fn get_dep_graph(metadata: Metadata, config: &Config) -> anyhow::Resu
                         continue;
                     }
 
+                    // Don't add dependencies of dependencies if we're at the depth limit
+                    if config.depth.is_some_and(|max_depth| depth >= max_depth) {
+                        continue;
+                    }
+
                     let dep_pkg = &get_package(&metadata.packages, &dep.pkg);
                     let dep_pkg = Package::new(dep_pkg, is_workspace_member);
 
@@ -99,10 +104,7 @@ pub(crate) fn get_dep_graph(metadata: Metadata, config: &Config) -> anyhow::Resu
 
                     let idx = graph.add_node(dep_pkg);
 
-                    // Don't add any more dependencies to the queue if we only want direct dependencies
-                    if !config.direct_dependencies_only {
-                        deps_add_queue.push_back(dep.pkg.clone());
-                    }
+                    deps_add_queue.push_back((dep.pkg.clone(), depth + 1));
 
                     v.insert(idx);
                     idx