Add simple test for syntax_node_to_token_tree_censored

Cargo.lock

@@ -888,6 +888,7 @@ name = "mbe"
 version = "0.0.0"
 dependencies = [
  "cov-mark",
+ "expect-test",
  "log",
  "parser",
  "profile",

crates/mbe/Cargo.toml

@@ -13,6 +13,7 @@ cov-mark = "2.0.0-pre.1"
 rustc-hash = "1.1.0"
 smallvec = "1.2.0"
 log = "0.4.8"
+expect-test = "1.1"
 
 syntax = { path = "../syntax", version = "0.0.0" }
 parser = { path = "../parser", version = "0.0.0" }

crates/mbe/src/syntax_bridge.rs

@@ -15,14 +15,14 @@ use tt::buffer::{Cursor, TokenBuffer};
 use crate::{subtree_source::SubtreeTokenSource, tt_iter::TtIter};
 use crate::{ExpandError, TokenMap};
 
-/// Convert the syntax node to a `TokenTree` with the censored nodes excluded (what macro
+/// Convert the syntax node to a `TokenTree` (what macro
 /// will consume).
 pub fn syntax_node_to_token_tree(node: &SyntaxNode) -> (tt::Subtree, TokenMap) {
     syntax_node_to_token_tree_censored(node, None)
 }
 
-/// Convert the syntax node to a `TokenTree` with the censored nodes excluded (what macro
-/// will consume).
+/// Convert the syntax node to a `TokenTree` (what macro will consume)
+/// with the censored range excluded.
 pub fn syntax_node_to_token_tree_censored(
     node: &SyntaxNode,
     censor: Option<TextRange>,

crates/mbe/src/tests.rs

@@ -228,3 +228,44 @@ fn debug_dump_ignore_spaces(node: &syntax::SyntaxNode) -> String {
 
     buf
 }
+
+#[test]
+fn test_node_to_tt_censor() {
+    use syntax::ast::{AttrsOwner, ModuleItemOwner};
+
+    let source = r##"
+#[attr0]
+#[attr1]
+#[attr2]
+struct Struct {
+    field: ()
+}
+"##;
+    let source_file = ast::SourceFile::parse(&source).ok().unwrap();
+    let item = source_file.items().next().unwrap();
+    let attr = item.attrs().nth(1).unwrap();
+
+    let (tt, _) =
+        syntax_node_to_token_tree_censored(item.syntax(), Some(attr.syntax().text_range()));
+    expect_test::expect![[r##"# [attr0] # [attr2] struct Struct {field : ()}"##]]
+        .assert_eq(&tt.to_string());
+
+    let source = r##"
+#[derive(Derive0)]
+#[derive(Derive1)]
+#[derive(Derive2)]
+struct Struct {
+    field: ()
+}
+"##;
+    let source_file = ast::SourceFile::parse(&source).ok().unwrap();
+    let item = source_file.items().next().unwrap();
+    let attr = item.attrs().nth(1).unwrap();
+
+    let (tt, _) = syntax_node_to_token_tree_censored(
+        item.syntax(),
+        Some(attr.syntax().text_range().cover_offset(0.into())),
+    );
+    expect_test::expect![[r##"# [derive (Derive2)] struct Struct {field : ()}"##]]
+        .assert_eq(&tt.to_string());
+}