From b4e90a723a53389f5d57760414fbd7c7dd226639 Mon Sep 17 00:00:00 2001
From: Cameron <cameron.clark@hey.com>
Date: Fri, 1 Dec 2023 12:52:26 +0000
Subject: [PATCH] feat(prettier): implement `has_comment`, improve blank lines
 when printing arrays (#1601)

---
 crates/oxc_prettier/src/comments/mod.rs   | 10 +++++++
 crates/oxc_prettier/src/comments/print.rs | 34 +++++++++++++++++++++--
 crates/oxc_prettier/src/format/array.rs   |  8 +++++-
 3 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/crates/oxc_prettier/src/comments/mod.rs b/crates/oxc_prettier/src/comments/mod.rs
index 47358c1d4..9f303d6a3 100644
--- a/crates/oxc_prettier/src/comments/mod.rs
+++ b/crates/oxc_prettier/src/comments/mod.rs
@@ -26,6 +26,16 @@ impl Comment {
         self.has_line_suffix = yes;
         self
     }
+
+    pub fn matches_flags(self, flags: CommentFlags) -> bool {
+        if flags.contains(CommentFlags::Block) && !self.is_block {
+            return false;
+        }
+        if flags.contains(CommentFlags::Line) && self.is_block {
+            return false;
+        }
+        true
+    }
 }
 
 #[derive(Default)]
diff --git a/crates/oxc_prettier/src/comments/print.rs b/crates/oxc_prettier/src/comments/print.rs
index dea8917e8..1c674e645 100644
--- a/crates/oxc_prettier/src/comments/print.rs
+++ b/crates/oxc_prettier/src/comments/print.rs
@@ -31,8 +31,38 @@ impl<'a> Prettier<'a> {
         doc
     }
 
-    #[allow(unused)]
-    pub(crate) fn has_comment(_span: Span, _flags: CommentFlags) -> bool {
+    pub(crate) fn has_comment(&mut self, range: Span, flags: CommentFlags) -> bool {
+        let mut peekable_trivias = self.trivias.clone();
+
+        while let Some(&(start, end, kind)) = peekable_trivias.peek() {
+            let mut should_break = true;
+            let comment = Comment::new(start, end, kind);
+
+            if range.end < comment.start
+                && self.source_text[range.end as usize..comment.start as usize]
+                    .chars()
+                    .all(|c| c == ' ')
+            {
+                if flags.contains(CommentFlags::Trailing) && comment.matches_flags(flags) {
+                    return true;
+                }
+
+                should_break = false;
+            }
+
+            if comment.end <= range.end {
+                if flags.contains(CommentFlags::Dangling) && comment.matches_flags(flags) {
+                    return true;
+                }
+                should_break = false;
+            }
+
+            if should_break {
+                break;
+            }
+            peekable_trivias.next();
+        }
+
         false
     }
 
diff --git a/crates/oxc_prettier/src/format/array.rs b/crates/oxc_prettier/src/format/array.rs
index 4d677f51f..fd7013875 100644
--- a/crates/oxc_prettier/src/format/array.rs
+++ b/crates/oxc_prettier/src/format/array.rs
@@ -4,7 +4,7 @@ use oxc_syntax::operator::UnaryOperator;
 
 use crate::{
     array,
-    comments::DanglingCommentsPrintOptions,
+    comments::{CommentFlags, DanglingCommentsPrintOptions},
     doc::{Doc, DocBuilder, Fill, Group},
     group, hardline, if_break, indent, line, softline, ss, Prettier,
 };
@@ -217,6 +217,12 @@ where
                         space_parts.extend(hardline!());
                         space_parts.extend(hardline!());
                         parts.push(Doc::Array(space_parts));
+                    } else if array.elements.get(i + 1).is_some_and(|next| {
+                        p.has_comment(next.span(), CommentFlags::Leading | CommentFlags::Line)
+                    }) {
+                        let mut space_parts = p.vec();
+                        space_parts.extend(hardline!());
+                        parts.push(Doc::Array(space_parts));
                     } else {
                         parts.push(line!());
                     }