Fix the formatting of function parameters whose types are functions w…

…ith modifier lists. These were not treated properly as blocks before, resulting in line breaks being inserted incorrectly and without proper indentation.
hovinen · Mar 18, 2021 · 2c2cf35 · 2c2cf35
1 parent 837f1c7
commit 2c2cf35
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Showing 4 changed files with 74 additions and 2 deletions.
diff --git a/formatter/src/main/kotlin/org/kotlin/formatter/scanning/NodeScanner.kt b/formatter/src/main/kotlin/org/kotlin/formatter/scanning/NodeScanner.kt
@@ -64,6 +64,7 @@ internal class NodeScannerProvider(
     private val parenthesizedScanner = lazy { ParenthesizedScanner(kotlinScanner) }
     private val labeledExpressionScanner = lazy { LabeledExpressionScanner(kotlinScanner) }
     private val annotatedExpressionScanner = lazy { AnnotatedExpressionScanner(kotlinScanner) }
+    private val typeReferenceScanner = lazy { TypeReferenceScanner(kotlinScanner) }
     private val simpleScannerForBlock = lazy { SimpleScanner(kotlinScanner, ScannerState.BLOCK) }
     private val simpleBlockScanner =
         lazy { SimpleBlockScanner(kotlinScanner, ScannerState.STATEMENT, State.CODE) }
@@ -122,6 +123,7 @@ internal class NodeScannerProvider(
             KtFileElementType.INSTANCE -> kotlinFileScanner.value
             KtFileElementType.INSTANCE, is KtScriptElementType,
                 KtNodeTypes.LITERAL_STRING_TEMPLATE_ENTRY -> simpleScannerForBlock.value
+            KtNodeTypes.TYPE_REFERENCE -> typeReferenceScanner.value
             KtNodeTypes.WHEN_ENTRY, KtNodeTypes.ANNOTATION_ENTRY, KtNodeTypes.PREFIX_EXPRESSION,
                 KtNodeTypes.VALUE_PARAMETER, KtNodeTypes.SUPER_TYPE_ENTRY,
                 KtNodeTypes.SUPER_TYPE_CALL_ENTRY, KtNodeTypes.USER_TYPE,

diff --git a/formatter/src/main/kotlin/org/kotlin/formatter/scanning/ParameterListScanner.kt b/formatter/src/main/kotlin/org/kotlin/formatter/scanning/ParameterListScanner.kt
@@ -9,9 +9,11 @@ import org.kotlin.formatter.ClosingSynchronizedBreakToken
 import org.kotlin.formatter.ForcedBreakToken
 import org.kotlin.formatter.LeafNodeToken
 import org.kotlin.formatter.MarkerToken
+import org.kotlin.formatter.State
 import org.kotlin.formatter.SynchronizedBreakToken
 import org.kotlin.formatter.Token
 import org.kotlin.formatter.WhitespaceToken
+import org.kotlin.formatter.inBeginEndBlock
 import org.kotlin.formatter.scanning.nodepattern.NodePatternBuilder
 import org.kotlin.formatter.scanning.nodepattern.nodePattern
 
@@ -130,8 +132,26 @@ internal class ParameterListScanner(private val kotlinScanner: KotlinScanner) :
                     tokens
                 }
             }
-            oneOrMore { anyNode() } thenMapToTokens { nodes ->
-                kotlinScanner.scanNodes(nodes, ScannerState.STATEMENT).plus(BlockFromMarkerToken)
+            either {
+                nodeOfType(KtTokens.IDENTIFIER) thenMapToTokens { nodes ->
+                    kotlinScanner.scanNodes(nodes, ScannerState.STATEMENT)
+                }
+                possibleWhitespace()
+                nodeOfType(KtTokens.COLON) thenMapToTokens { listOf(LeafNodeToken(":")) }
+                possibleWhitespace() thenMapToTokens { nodes ->
+                    listOf(WhitespaceToken(nodes.map { it.text }.firstOrNull() ?: " "))
+                }
+                nodeOfType(KtNodeTypes.TYPE_REFERENCE) thenMapToTokens { nodes ->
+                    inBeginEndBlock(
+                        kotlinScanner.scanNodes(nodes, ScannerState.STATEMENT),
+                        State.CODE
+                    ).plus(BlockFromMarkerToken)
+                }
+            } or {
+                oneOrMore { anyNode() } thenMapToTokens { nodes ->
+                    kotlinScanner.scanNodes(nodes, ScannerState.STATEMENT)
+                        .plus(BlockFromMarkerToken)
+                }
             }
             end()
         }

diff --git a/formatter/src/main/kotlin/org/kotlin/formatter/scanning/TypeReferenceScanner.kt b/formatter/src/main/kotlin/org/kotlin/formatter/scanning/TypeReferenceScanner.kt
@@ -0,0 +1,27 @@
+package org.kotlin.formatter.scanning
+
+import org.jetbrains.kotlin.KtNodeTypes
+import org.jetbrains.kotlin.com.intellij.lang.ASTNode
+import org.jetbrains.kotlin.psi.psiUtil.children
+import org.kotlin.formatter.Token
+import org.kotlin.formatter.scanning.nodepattern.nodePattern
+
+/** A [NodeScanner] for references to types. */
+internal class TypeReferenceScanner(private val kotlinScanner: KotlinScanner) : NodeScanner {
+    private val nodePattern =
+        nodePattern {
+            zeroOrOne {
+                nodeOfType(KtNodeTypes.MODIFIER_LIST) thenMapToTokens { nodes ->
+                    kotlinScanner.scanNodes(nodes, ScannerState.STATEMENT)
+                }
+            }
+            possibleWhitespace()
+            oneOrMore { anyNode() } thenMapToTokens { nodes ->
+                kotlinScanner.scanNodes(nodes, ScannerState.STATEMENT)
+            }
+            end()
+        }
+
+    override fun scan(node: ASTNode, scannerState: ScannerState): List<Token> =
+        nodePattern.matchSequence(node.children().asIterable())
+}
diff --git a/formatter/src/test/kotlin/org/kotlin/formatter/KotlinFormatterTest.kt b/formatter/src/test/kotlin/org/kotlin/formatter/KotlinFormatterTest.kt
@@ -404,6 +404,29 @@ class KotlinFormatterTest {
             )
     }
 
+    @Test
+    fun `correctly indents parameter list when parameter is a suspend function`() {
+        val result =
+            KotlinFormatter(maxLineLength = 31)
+                .format("""fun aFunction(aParameter: suspend () -> T)""".trimIndent())
+
+        assertThat(result)
+            .isEqualTo(
+                """
+                    fun aFunction(
+                        aParameter: suspend () -> T
+                    )
+                """.trimIndent()
+            )
+    }
+
+    @Test
+    fun `fixes spacing around function parameter`() {
+        val result = KotlinFormatter().format("""fun aFunction(aParameter :T)""".trimIndent())
+
+        assertThat(result).isEqualTo("""fun aFunction(aParameter: T)""".trimIndent())
+    }
+
     @Test
     fun `does not break empty parameter list`() {
         val result =