fix: skip attrsets in patterns

src/main.rs

@@ -264,8 +264,13 @@ fn collect_entries(root: rnix::Root, prefix: &str, category: &str) -> Vec<Manual
     // we only need a single level of scope for this.
     // since only the body can export a function we don't need to implement
     // mutually recursive resolution.
-    for ev in root.syntax().preorder() {
+    let mut preorder = root.syntax().preorder();
+    while let Some(ev) = preorder.next() {
         match ev {
+            // Skip patterns. See test/patterns.nix for the reason why.
+            WalkEvent::Enter(n) if n.kind() == SyntaxKind::NODE_PATTERN => {
+                preorder.skip_subtree();
+            }
             WalkEvent::Enter(n) if n.kind() == SyntaxKind::NODE_LET_IN => {
                 return collect_bindings(
                     LetIn::cast(n.clone()).unwrap().body().unwrap().syntax(),

src/snapshots/nixdoc__test__patterns.snap

@@ -0,0 +1,7 @@
+---
+source: src/test.rs
+expression: output
+---
+## `lib.debug.iAmTopLevel` {#function-library-lib.debug.iAmTopLevel}
+
+This binding is in the top-level attrset

src/test.rs

@@ -227,3 +227,22 @@ fn test_empty_prefix() {
     assert_eq!(ident, "test.mapSimple-prime");
     assert_eq!(title, "test.mapSimple'");
 }
+
+#[test]
+fn test_patterns() {
+    let mut output = Vec::new();
+    let src = fs::read_to_string("test/patterns.nix").unwrap();
+    let nix = rnix::Root::parse(&src).ok().expect("failed to parse input");
+    let prefix = "lib";
+    let category = "debug";
+
+    for entry in collect_entries(nix, prefix, category) {
+        entry
+            .write_section(&Default::default(), &mut output)
+            .expect("Failed to write section")
+    }
+
+    let output = String::from_utf8(output).expect("not utf8");
+
+    insta::assert_snapshot!(output);
+}

test/patterns.nix

@@ -0,0 +1,13 @@
+{ 
+  pkgs ? import <nixpkgs>
+    # | This attrset must be skipped -- it is not the top-level attrset
+    # ↓ even though it comes first!
+    {   }
+}:
+
+{
+  /** 
+    This binding is in the top-level attrset
+  */
+  iAmTopLevel = null;
+}