add formatting for doc-comments

src/alejandra/src/children.rs

@@ -193,14 +193,26 @@ fn dedent_comment(pos: &crate::position::Position, text: &str) -> String {
     if text.starts_with('#') {
         text.to_string()
     } else {
-        let mut lines: Vec<String> = text[2..text.len() - 2]
-            .lines()
-            .map(|line| line.to_string())
-            .collect();
+        let is_doc = text.starts_with("/**") && !text.starts_with("/**/");
+        let mut lines: Vec<String> = if is_doc {
+            text[3..text.len() - 2]
+                .lines()
+                .map(|line| line.to_string())
+                .collect()
+        } else {
+            text[2..text.len() - 2]
+                .lines()
+                .map(|line| line.to_string())
+                .collect()
+        };
 
         // If all lines are whitespace just return a compact comment
         if lines.iter().all(|line| line.trim().is_empty()) {
-            return "/**/".to_string();
+            if is_doc {
+                return "/***/".to_string();
+            } else {
+                return "/**/".to_string();
+            }
         }
 
         // Make sure it starts with empty line
@@ -279,7 +291,10 @@ fn dedent_comment(pos: &crate::position::Position, text: &str) -> String {
                 }
             })
             .collect();
-
-        format!("/*{}*/", lines.join("\n"))
+        if is_doc {
+            format!("/**{}*/", lines.join("\n"))
+        } else {
+            format!("/*{}*/", lines.join("\n"))
+        }
     }
 }

src/alejandra/tests/cases/comment/in.nix

@@ -17,6 +17,15 @@
     */
 
   /*@*/
+
+  /**@*/
+
+  /**@
+  @
+  @*/
+
+  /**
+   */
 
   /**
     @

src/alejandra/tests/cases/comment/out.nix

@@ -14,8 +14,19 @@
   @
   */
 
-  /*
-   *
+  /**
+  @
+  */
+
+  /**
+    @
+  @
+  @
+  */
+
+  /***/
+
+  /**
    @
   *
   */