From db67ff7f05a1b7d3fa60fff90fe199fc201230c0 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Wed, 8 Dec 2021 10:59:34 -0800
Subject: [PATCH] FormatWriter: format `@usecase` tag on one line

Apparently, scaladoc doesn't allow newlines for this specific tag.
---
 .../scala/org/scalafmt/internal/FormatWriter.scala    | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala
index 4552ef0975..4802bb676b 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala
@@ -771,9 +771,14 @@ class FormatWriter(formatOps: FormatOps) {
                   t.label.foreach(x => sb.append(' ').append(x.syntax))
                   t.desc.foreach { x =>
                     val words = x.part.iterator.map(_.syntax)
-                    val tagMargin = getIndentation(2 + margin.length)
-                    // use maxLength to force a newline
-                    iterWords(words, appendBreak, maxLength, tagMargin)
+                    if (t.tag.tag == "@usecase")
+                      // scaladoc parser doesn't allow newlines in @usecase
+                      words.foreach(sb.append(' ').append(_))
+                    else {
+                      val tagMargin = getIndentation(2 + margin.length)
+                      // use maxLength to force a newline
+                      iterWords(words, appendBreak, maxLength, tagMargin)
+                    }
                   }
                   appendBreak()
                 case t: Scaladoc.ListBlock =>