fix: correct formatting comment after tailing comma on single line with "trailingCommas": "always" (#449)

Author: dsherret

Cargo.lock

@@ -34,5 +34,5 @@ serde_json = { version = "1.0", optional = true }
 
 [dev-dependencies]
 debug-here = "0.2"
-dprint-development = "0.9.1"
+dprint-development = "0.9.2"
 serde_json = { version = "1.0" }

Cargo.toml

@@ -7050,6 +7050,7 @@ where
           Signal::NewLine.into(),
         ));
       } else {
+        let last_comma_token = nodes.last().and_then(|n| context.token_finder.get_next_token_if_comma(n));
         items.extend(gen_separated_values(
           GenSeparatedValuesParams {
             nodes: nodes.into_iter().map(NodeOrSeparator::Node).collect(),
@@ -7066,6 +7067,10 @@ where
           },
           context,
         ));
+        // the comma may disappear, so generate any trailing comments on the same line
+        if let Some(last_comma_token) = last_comma_token {
+          items.extend(gen_trailing_comments_same_line(&last_comma_token.range(), context));
+        }
       }
 
       items

src/generation/generate.rs

@@ -70,3 +70,27 @@ export async function acceptWebSocket(req = {
     other: 7,
 }): Promise<WebSocket> {
 }
+
+== should keep comment and remove trailing comma on single line ==
+function test(test, /* test */) {
+}
+
+[expect]
+function test(test /* test */) {
+}
+
+== should handle comments on next line ==
+function test(
+    test, /* test */
+    /* test */
+    // test
+) {
+}
+
+[expect]
+function test(
+    test, /* test */
+    /* test */
+    // test
+) {
+}

tests/specs/general/Parameters_All.txt

@@ -0,0 +1,14 @@
+~~ indentWidth: 2, quoteStyle: alwaysSingle, semiColons: always, trailingCommas: always ~~
+== should handle comment in place of parameter ==
+function hasDeepProp(target /* , param1, param2, ... */) {
+}
+
+function hasDeepProp(target, /* , param1, param2, ... */) {
+}
+
+[expect]
+function hasDeepProp(target, /* , param1, param2, ... */) {
+}
+
+function hasDeepProp(target, /* , param1, param2, ... */) {
+}