Don't insert trailing commas over the max width

Closes facebook#472
nreid260 · Jun 4, 2024 · 388118a · 388118a
1 parent 9a916b7
commit 388118a
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Showing 2 changed files with 38 additions and 5 deletions.
diff --git a/core/src/main/java/com/facebook/ktfmt/format/RedundantElementManager.kt b/core/src/main/java/com/facebook/ktfmt/format/RedundantElementManager.kt
@@ -107,15 +107,24 @@ object RedundantElementManager {
         })
 
     val result = StringBuilder(code)
-    val suggestionElements = trailingCommaSuggestor.getTrailingCommaSuggestions()
-
-    for (element in suggestionElements.sortedByDescending(PsiElement::endOffset)) {
-      result.insert(element.endOffset, ',')
-    }
+    trailingCommaSuggestor.getTrailingCommaSuggestions()
+        .asSequence()
+        .sortedByDescending(PsiElement::endOffset)
+        .filter {
+          // https://github.com/facebook/ktfmt/issues/472
+          it.endColumnZero() < options.maxWidth
+        }
+        .forEach { result.insert(it.endOffset, ',') }
 
     return result.toString()
   }
 
+  private fun PsiElement.endColumnZero(): Int {
+    val document = this.containingFile.viewProvider.document!!
+    val zeroLineNumber = document.getLineNumber(this.endOffset)
+    return this.endOffset - document.getLineStartOffset(zeroLineNumber)
+  }
+
   private fun PsiElement?.containsNewline(): Boolean {
     if (this !is PsiWhiteSpace) return false
     return this.text.contains('\n')

diff --git a/core/src/test/java/com/facebook/ktfmt/format/GoogleStyleFormatterKtTest.kt b/core/src/test/java/com/facebook/ktfmt/format/GoogleStyleFormatterKtTest.kt
@@ -1832,6 +1832,30 @@ class GoogleStyleFormatterKtTest {
     assertThatFormatting(code).withOptions(Formatter.GOOGLE_FORMAT).isEqualTo(expected)
   }
 
+  @Test
+  fun `trailing commas are not inserted over the max width`() =
+      assertFormatted(
+          """
+      |//////////////////
+      |fun foo() {
+      |  bar(
+      |    someArg,
+      |    justBeforeMax,
+      |  )
+      |  bar(
+      |    someArg,
+      |    exactlyAtMaaax
+      |  )
+      |  bar(
+      |    someArg,
+      |    justAfterMaaaax
+      |  )
+      |}
+      |"""
+              .trimMargin(),
+          formattingOptions = Formatter.GOOGLE_FORMAT,
+          deduceMaxWidth = true)
+
   companion object {
     /** Triple quotes, useful to use within triple-quoted strings. */
     private const val TQ = "\"\"\""