move fuzz-invariants to the library

crates/libsyntax2/fuzz/fuzz_targets/parser.rs

@@ -4,9 +4,6 @@ extern crate libsyntax2;
 
 fuzz_target!(|data: &[u8]| {
     if let Ok(text) = std::str::from_utf8(data) {
-        let x = libsyntax2::File::parse(text);
-        let _ = x.ast();
-        let _ = x.syntax();
-        let _ = x.errors();
+        libsyntax2::utils::check_fuzz_invariants(text)
     }
 });

crates/libsyntax2/src/lib.rs

@@ -66,7 +66,9 @@ impl File {
     fn new(green: GreenNode, errors: Vec<SyntaxError>) -> File {
         let root = SyntaxRoot::new(green, errors);
         let root = SyntaxNode::new_owned(root);
-        validate_block_structure(root.borrowed());
+        if cfg!(debug_assertions) {
+            utils::validate_block_structure(root.borrowed());
+        }
         File { root }
     }
     pub fn parse(text: &str) -> File {
@@ -112,40 +114,6 @@ impl File {
     }
 }
 
-#[cfg(not(debug_assertions))]
-fn validate_block_structure(_: SyntaxNodeRef) {}
-
-#[cfg(debug_assertions)]
-fn validate_block_structure(root: SyntaxNodeRef) {
-    let mut stack = Vec::new();
-    for node in algo::walk::preorder(root) {
-        match node.kind() {
-            SyntaxKind::L_CURLY => {
-                stack.push(node)
-            }
-            SyntaxKind::R_CURLY => {
-                if let Some(pair) = stack.pop() {
-                    assert_eq!(
-                        node.parent(),
-                        pair.parent(),
-                        "\nunpaired curleys:\n{}\n{}\n",
-                        root.text(),
-                        utils::dump_tree(root),
-                    );
-                    assert!(
-                        node.next_sibling().is_none() && pair.prev_sibling().is_none(),
-                        "\nfloating curlys at {:?}\nfile:\n{}\nerror:\n{}\n",
-                        node,
-                        root.text(),
-                        node.text(),
-                    );
-                }
-            }
-            _ => (),
-        }
-    }
-}
-
 #[derive(Debug, Clone)]
 pub struct AtomEdit {
     pub delete: TextRange,

crates/libsyntax2/src/utils.rs

@@ -1,7 +1,7 @@
 use std::fmt::Write;
 use {
-    algo::walk::{walk, WalkEvent},
-    SyntaxNodeRef, TreeRoot,
+    algo::walk::{preorder, walk, WalkEvent},
+    SyntaxKind, File, SyntaxNodeRef, TreeRoot,
 };
 
 /// Parse a file and create a string representation of the resulting parse tree.
@@ -45,3 +45,41 @@ pub fn dump_tree(syntax: SyntaxNodeRef) -> String {
 
     return buf;
 }
+
+pub fn check_fuzz_invariants(text: &str) {
+    let file = File::parse(text);
+    let root = file.syntax();
+    validate_block_structure(root);
+    let _ = file.ast();
+    let _ = file.errors();
+}
+
+pub(crate) fn validate_block_structure(root: SyntaxNodeRef) {
+    let mut stack = Vec::new();
+    for node in preorder(root) {
+        match node.kind() {
+            SyntaxKind::L_CURLY => {
+                stack.push(node)
+            }
+            SyntaxKind::R_CURLY => {
+                if let Some(pair) = stack.pop() {
+                    assert_eq!(
+                        node.parent(),
+                        pair.parent(),
+                        "\nunpaired curleys:\n{}\n{}\n",
+                        root.text(),
+                        dump_tree(root),
+                    );
+                    assert!(
+                        node.next_sibling().is_none() && pair.prev_sibling().is_none(),
+                        "\nfloating curlys at {:?}\nfile:\n{}\nerror:\n{}\n",
+                        node,
+                        root.text(),
+                        node.text(),
+                    );
+                }
+            }
+            _ => (),
+        }
+    }
+}