feat: support const type parameters (#491)

Author: dsherret

Cargo.lock

@@ -26,7 +26,7 @@ tracing = ["dprint-core/tracing"]
 
 [dependencies]
 anyhow = "1.0.64"
-deno_ast = { version = "0.23.2", features = ["view"] }
+deno_ast = { version = "0.24.0", features = ["view"] }
 dprint-core = { version = "0.60.0", features = ["formatting"] }
 rustc-hash = "1.1.0"
 serde = { version = "1.0.144", features = ["derive"] }

Cargo.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.66.0"
+channel = "1.67.0"
 components = ["clippy"]

rust-toolchain.toml

@@ -170,7 +170,7 @@ impl<'a> Context<'a> {
   pub fn assert_text(&self, range: SourceRange, expected_text: &str) {
     let actual_text = range.text_fast(self.program);
     if actual_text != expected_text {
-      panic!("Debug Panic Expected text `{}`, but found `{}`", expected_text, actual_text)
+      panic!("Debug Panic Expected text `{expected_text}`, but found `{actual_text}`")
     }
   }
 }

src/generation/context.rs

@@ -5830,6 +5830,9 @@ fn gen_type_ann<'a>(node: &'a TsTypeAnn, context: &mut Context<'a>) -> PrintItem
 fn gen_type_param<'a>(node: &'a TsTypeParam, context: &mut Context<'a>) -> PrintItems {
   let mut items = PrintItems::new();
 
+  if node.is_const() {
+    items.push_str("const ");
+  }
   if node.is_in() {
     items.push_str("in ");
   }
@@ -8856,7 +8859,7 @@ fn gen_assignment_like_with_token<'a>(expr: Node<'a>, op: &'static str, op_token
   if op == ":" {
     items.push_str(op)
   } else {
-    items.push_string(format!(" {}", op))
+    items.push_string(format!(" {op}"))
   }
 
   let op_end = op_token
@@ -9131,11 +9134,11 @@ fn gen_surrounded_by_tokens<'a>(
 }
 
 #[cfg(debug_assertions)]
-fn assert_has_op<'a>(op: &str, op_token: Option<&TokenAndSpan>, context: &mut Context<'a>) {
+fn assert_has_op(op: &str, op_token: Option<&TokenAndSpan>, context: &mut Context) {
   if let Some(op_token) = op_token {
     context.assert_text(SourceRange::new(op_token.start(), op_token.end()), op);
   } else {
-    panic!("Debug panic! Expected to have op token: {}", op);
+    panic!("Debug panic! Expected to have op token: {op}");
   }
 }
 

src/generation/generate.rs

@@ -4,6 +4,7 @@
 #![allow(clippy::if_same_then_else)]
 #![allow(clippy::vec_init_then_push)]
 #![allow(clippy::type_complexity)]
+#![allow(clippy::needless_lifetimes)] // todo: enable this in the future
 #![deny(clippy::disallowed_methods)]
 #![deny(clippy::disallowed_types)]
 

src/lib.rs

@@ -88,7 +88,7 @@ pub fn ensure_no_specific_syntax_errors(parsed_source: &ParsedSource) -> Result<
       if !final_message.is_empty() {
         final_message.push_str("\n\n");
       }
-      final_message.push_str(&format!("{}", diagnostic));
+      final_message.push_str(&format!("{diagnostic}"));
     }
     bail!("{}", final_message)
   }

src/swc.rs

@@ -1,11 +1,12 @@
 ~~ lineWidth: 40 ~~
 == should put type parameters on multiple lines when they extend beyond the line width ==
-class Test<T, TestingThisOut extends number> {
+class Test<T, const U, TestingThisOut extends number> {
 }
 
 [expect]
 class Test<
     T,
+    const U,
     TestingThisOut extends number,
 > {
 }

tests/specs/types/TypeParameter/TypeParameter_All.txt

@@ -39,8 +39,11 @@ fn test_performance() {
 #[test]
 fn test_specs() {
   //debug_here!();
-  let mut global_config = GlobalConfiguration::default();
-  global_config.indent_width = Some(4); // for the tests only because a higher indent width increases the likelihood of problems
+  let mut global_config = GlobalConfiguration {
+    // for the tests only because a higher indent width increases the likelihood of problems
+    indent_width: Some(4),
+    ..Default::default()
+  };
 
   run_specs(
     &PathBuf::from("./tests/specs"),
@@ -50,7 +53,7 @@ fn test_specs() {
       format_twice: true,
     },
     {
-      let global_config = global_config.clone();
+      let global_config = global_config;
       move |file_name, file_text, spec_config| {
         let config_result = resolve_config(parse_config_key_map(spec_config), &global_config);
         ensure_no_diagnostics(&config_result.diagnostics);