Preserve a trailing space when lambda has only block comments

This fixes facebook#408
fredyw · Oct 5, 2023 · 27af02f · 27af02f
1 parent 102c89d
commit 27af02f
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/core/src/main/java/com/facebook/ktfmt/format/KotlinInputAstVisitor.kt b/core/src/main/java/com/facebook/ktfmt/format/KotlinInputAstVisitor.kt
@@ -889,6 +889,7 @@ class KotlinInputAstVisitor(
     val valueParams = lambdaExpression.valueParameters
     val hasParams = valueParams.isNotEmpty()
     val statements = (lambdaExpression.bodyExpression ?: fail()).children
+    val hasComments = lambdaExpression.bodyExpression?.children()?.any { it is PsiComment } ?: false
     val hasStatements = statements.isNotEmpty()
     val hasArrow = lambdaExpression.functionLiteral.arrow != null
 
@@ -944,7 +945,7 @@ class KotlinInputAstVisitor(
       }
     }
 
-    if (hasParams || hasArrow || hasStatements) {
+    if (hasParams || hasArrow || hasStatements || hasComments) {
       // If we had to break in the body, ensure there is a break before the closing brace
       builder.breakOp(Doc.FillMode.UNIFIED, " ", bracePlusZeroIndent)
     }

diff --git a/core/src/test/java/com/facebook/ktfmt/format/FormatterTest.kt b/core/src/test/java/com/facebook/ktfmt/format/FormatterTest.kt
@@ -5808,6 +5808,15 @@ class FormatterTest {
       |"""
               .trimMargin())
 
+  @Test
+  fun `lambda with only comments`() =
+      assertFormatted(
+          """
+      |val a = { /* do nothing */ }
+      |val b = { /* do nothing */ /* also do nothing */ }
+      |"""
+              .trimMargin())
+
   @Test
   fun `chaining - many dereferences`() =
       assertFormatted(