(Unify workspace and package fuzzy dependency lookup)

src/cargo/ops/cargo_add/mod.rs

@@ -364,23 +364,8 @@ fn resolve_dependency(
     };
     selected_dep = populate_dependency(selected_dep, arg);
 
-    let mut old_dep = get_existing_dependency(manifest, selected_dep.toml_key(), section)?;
-    if old_dep.is_none() && selected_dep.source().is_none() && selected_dep.rename().is_none() {
-        for name_permutation in [
-            selected_dep.name.replace('-', "_"),
-            selected_dep.name.replace('_', "-"),
-        ] {
-            old_dep = get_existing_dependency(manifest, &name_permutation, section)?;
-            if old_dep.is_some() {
-                gctx.shell().warn(format!(
-                    "translating `{}` to `{}`",
-                    selected_dep.name, &name_permutation,
-                ))?;
-                selected_dep.name = name_permutation;
-                break;
-            }
-        }
-    }
+    let lookup = |dep_key: &_| get_existing_dependency(manifest, dep_key, section);
+    let old_dep = fuzzy_lookup(&mut selected_dep, lookup, gctx)?;
 
     let mut dependency = if let Some(mut old_dep) = old_dep.clone() {
         if old_dep.name != selected_dep.name {
@@ -488,6 +473,40 @@ fn resolve_dependency(
     Ok(dependency)
 }
 
+fn fuzzy_lookup(
+    dependency: &mut Dependency,
+    lookup: impl Fn(&str) -> CargoResult<Option<Dependency>>,
+    gctx: &GlobalContext,
+) -> CargoResult<Option<Dependency>> {
+    if let Some(rename) = dependency.rename() {
+        return lookup(rename);
+    }
+
+    for name_permutation in [
+        dependency.name.clone(),
+        dependency.name.replace('-', "_"),
+        dependency.name.replace('_', "-"),
+    ] {
+        let Some(dep) = lookup(&name_permutation)? else {
+            continue;
+        };
+
+        if dependency.name != name_permutation {
+            if !matches!(dep.source, Some(Source::Registry(_))) {
+                continue;
+            }
+            gctx.shell().warn(format!(
+                "translating `{}` to `{}`",
+                dependency.name, &name_permutation,
+            ))?;
+            dependency.name = name_permutation;
+        }
+        return Ok(Some(dep));
+    }
+
+    Ok(None)
+}
+
 /// When { workspace = true } you cannot define other keys that configure
 /// the source of the dependency such as `version`, `registry`, `registry-index`,
 /// `path`, `git`, `branch`, `tag`, `rev`, or `package`. You can also not define