fix some fmt issue

Author: CppCXY

crates/emmylua_formatter/src/formatter/expr.rs

@@ -2532,23 +2532,46 @@ fn try_format_simple_inline_closure_expr(
     }
 
     let mut stats = block.get_stats();
-    let LuaStat::ReturnStat(return_stat) = stats.next()? else {
-        return None;
-    };
-    if stats.next().is_some() || node_has_direct_comment_child(return_stat.syntax()) {
-        return None;
-    }
-
-    let mut returned_exprs = return_stat.get_expr_list();
-    let returned_expr = returned_exprs.next()?;
-    if returned_exprs.next().is_some() {
+    let first_stat = stats.next()?;
+    if stats.next().is_some() || node_has_direct_comment_child(first_stat.syntax()) {
         return None;
     }
 
-    let returned_docs = format_expr(ctx, plan, &returned_expr);
-    if ir::ir_has_forced_line_break(&returned_docs) {
-        return None;
-    }
+    // Format a single-statement closure inline: `function (args) stmt end`.
+    // Supports return, call, and other statement types subject to line-width constraint.
+    let body_docs: Vec<DocIR> = match &first_stat {
+        LuaStat::ReturnStat(return_stat) => {
+            let mut returned_exprs = return_stat.get_expr_list();
+            let returned_expr = returned_exprs.next()?;
+            if returned_exprs.next().is_some() {
+                return None;
+            }
+            let returned_docs = format_expr(ctx, plan, &returned_expr);
+            if ir::ir_has_forced_line_break(&returned_docs) {
+                return None;
+            }
+            let mut docs = vec![ir::syntax_token(LuaTokenKind::TkReturn)];
+            docs.push(ir::space());
+            docs.extend(returned_docs);
+            docs
+        }
+        LuaStat::CallExprStat(call_stat) => {
+            let call_expr = call_stat.get_call_expr()?;
+            let docs = format_expr(ctx, plan, &call_expr.into());
+            if ir::ir_has_forced_line_break(&docs) {
+                return None;
+            }
+            docs
+        }
+        _ => {
+            let stmt_text = first_stat.syntax().text().to_string();
+            let trimmed = stmt_text.trim();
+            if trimmed.contains('\n') {
+                return None;
+            }
+            vec![ir::source_node_trimmed(first_stat.syntax().clone())]
+        }
+    };
 
     let mut docs = vec![ir::syntax_token(LuaTokenKind::TkFunction)];
     if let Some(params) = expr.get_params_list() {
@@ -2557,9 +2580,7 @@ fn try_format_simple_inline_closure_expr(
     }
     docs.extend(shell_plan.params);
     docs.push(ir::space());
-    docs.push(ir::syntax_token(LuaTokenKind::TkReturn));
-    docs.push(ir::space());
-    docs.extend(returned_docs);
+    docs.extend(body_docs);
     docs.push(ir::space());
     docs.push(ir::syntax_token(LuaTokenKind::TkEnd));
 

crates/emmylua_formatter/src/test/config_tests.rs

@@ -528,6 +528,51 @@ end
         );
     }
 
+    #[test]
+    fn test_simple_lambda_always_collapses_non_return_closure() {
+        let config = LuaFormatConfig {
+            output: OutputConfig {
+                simple_lambda_single_line: SimpleLambdaSingleLine::Always,
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+
+        assert_format_with_config!(
+            r#"buttonRegister(self._btnClose, function()
+    self:_onBtnEventClose()
+end)
+"#,
+            r#"buttonRegister(self._btnClose, function () self:_onBtnEventClose() end)
+"#,
+            config
+        );
+    }
+
+    #[test]
+    fn test_simple_lambda_never_expands_non_return_closure() {
+        let config = LuaFormatConfig {
+            output: OutputConfig {
+                simple_lambda_single_line: SimpleLambdaSingleLine::Never,
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+
+        assert_format_with_config!(
+            r#"buttonRegister(self._btnClose, function() self:_onBtnEventClose() end)
+"#,
+            r#"buttonRegister(
+    self._btnClose,
+    function ()
+        self:_onBtnEventClose()
+    end
+)
+"#,
+            config
+        );
+    }
+
     // ========== indentation ==========
 
     #[test]

crates/emmylua_formatter/src/test/expression_tests.rs

@@ -767,6 +767,16 @@ end)
         );
     }
 
+    #[test]
+    fn test_inline_lambda_callback_no_return_stays_inline() {
+        assert_format!(
+            r#"buttonRegister(self._btnClose, function() self:_onBtnEventClose() end)
+"#,
+            r#"buttonRegister(self._btnClose, function () self:_onBtnEventClose() end)
+"#
+        );
+    }
+
     #[test]
     fn test_simple_inline_lambda_callback_stays_inline() {
         assert_format!(