inputs: support removal of deeply nested follows

Handle `rm disko.nixpkgs` when the follows uses the attrset form:

  inputs = {
    nixpkgs = {
      follows = "nixpkgs";
    };
  };

Author: a-kenji

src/walk/inputs.rs

@@ -991,12 +991,49 @@ fn handle_input_attr_set(
 
             if leaf.to_string().starts_with("inputs") {
                 let id = child.prev_sibling().unwrap();
-                let context = id.to_string().into();
-                if let Some(replacement) =
-                    walk_inputs(inputs, child.clone(), &Some(context), change)
-                {
+                let context: Context = id.to_string().into();
+                let ctx_some = Some(context);
+                if let Some(replacement) = walk_inputs(inputs, child.clone(), &ctx_some, change) {
                     return Some(substitute_child(node, child.index(), &replacement));
                 }
+
+                // Handle deeply nested inputs attrset removal:
+                // `inputs = { nixpkgs = { follows = "nixpkgs"; }; }`
+                if leaf.to_string() == "inputs"
+                    && change.is_remove()
+                    && let Some(inputs_attrset) =
+                        attr.children().find(|c| c.kind() == SyntaxKind::NODE_ATTR_SET)
+                {
+                    for nested_entry in inputs_attrset.children() {
+                        if nested_entry.kind() != SyntaxKind::NODE_ATTRPATH_VALUE {
+                            continue;
+                        }
+                        let Some(nested_path) = nested_entry.first_child() else {
+                            continue;
+                        };
+                        let Some(nested_id) = nested_path.first_child() else {
+                            continue;
+                        };
+                        if should_remove_nested_input(
+                            change,
+                            &ctx_some,
+                            &nested_id.to_string(),
+                        ) {
+                            let new_inputs_attrset = remove_child_with_whitespace(
+                                &inputs_attrset,
+                                &nested_entry,
+                                nested_entry.index(),
+                            );
+                            let new_attr = substitute_child(
+                                &attr,
+                                inputs_attrset.index(),
+                                &new_inputs_attrset,
+                            );
+                            let new_child = substitute_child(child, attr.index(), &new_attr);
+                            return Some(substitute_child(node, child.index(), &new_child));
+                        }
+                    }
+                }
             }
         }
     }

tests/edit.rs

@@ -185,6 +185,7 @@ fn test_remove_input_walker(#[case] fixture: &str, #[case] input_id: &str) {
 #[case("root", "rust-overlay.flake-utils")]
 #[case("completely_flat_toplevel", "crane.rust-overlay")]
 #[case("one_level_nesting_flat", "rust-overlay.flake-utils")]
+#[case("deeply_nested_inputs", "disko.nixpkgs")]
 fn test_remove_nested_input(#[case] fixture: &str, #[case] input_id: &str) {
     let content = load_flake(fixture);
     let mut flake_edit = FlakeEdit::from_text(&content).unwrap();

tests/snapshots/cli__remove@deeply_nested_inputs_nixpkgs.snap

@@ -16,13 +16,20 @@ exit_code: 0
 ----- stdout -----
 --- original
 +++ modified
-@@ -2,7 +2,6 @@
+@@ -2,14 +2,10 @@
    description = "Deeply nested inputs attrset";
 
    inputs = {
 -    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
 
      disko = {
        url = "github:nix-community/disko";
+       inputs = {
+-        nixpkgs = {
+-          follows = "nixpkgs";
+-        };
+       };
+     };
+   };
 
 ----- stderr -----

tests/snapshots/cli__remove@root_alt_nixpkgs.snap

@@ -24,5 +24,21 @@ exit_code: 0
 
      flake-utelinos.url = "github:numtide/flake-utils";
 
+@@ -9,7 +8,6 @@
+     rust-overlay = {
+       url = "github:oxalica/rust-overlay";
+       inputs = {
+-        nixpkgs.follows = "nixpkgs";
+         flake-utils.follows = "flake-utils";
+       };
+     };
+@@ -16,7 +14,6 @@
+     crane = {
+       url = "github:ipetkov/crane";
+       inputs = {
+-        nixpkgs.follows = "nixpkgs";
+         rust-overlay.follows = "rust-overlay";
+         flake-utils.follows = "flake-utils";
+       };
 
 ----- stderr -----

tests/snapshots/edit__remove_nested_input@deeply_nested_inputs_disko_nixpkgs.snap

@@ -0,0 +1,25 @@
+---
+source: tests/edit.rs
+expression: result
+info:
+  flake_nix: ""
+  changes:
+    - Remove:
+        ids:
+          - disko.nixpkgs
+---
+{
+  description = "Deeply nested inputs attrset";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+
+    disko = {
+      url = "github:nix-community/disko";
+      inputs = {
+      };
+    };
+  };
+
+  outputs = _: { };
+}