From f6d3fb1228d8b80d8326c3fe7a05d1fac9d22cef Mon Sep 17 00:00:00 2001
From: Islon Scherer <i_desouzascherer@apple.com>
Date: Tue, 21 Oct 2025 09:45:27 +0200
Subject: [PATCH] Fix let formatting (#1246)

---
 .../src/main/kotlin/org/pkl/formatter/Builder.kt    |  2 +-
 .../files/FormatterSnippetTests/input/expr-let.pkl  |  6 ++++++
 .../test/files/FormatterSnippetTests/input/when.pkl |  9 +++++++++
 .../files/FormatterSnippetTests/output/expr-let.pkl | 13 +++++++++++--
 .../files/FormatterSnippetTests/output/when.pkl     | 11 +++++++++++
 .../src/main/java/org/pkl/parser/GenericParser.java |  2 +-
 6 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/pkl-formatter/src/main/kotlin/org/pkl/formatter/Builder.kt b/pkl-formatter/src/main/kotlin/org/pkl/formatter/Builder.kt
index 02e6f0dd..9b627412 100644
--- a/pkl-formatter/src/main/kotlin/org/pkl/formatter/Builder.kt
+++ b/pkl-formatter/src/main/kotlin/org/pkl/formatter/Builder.kt
@@ -791,7 +791,7 @@ internal class Builder(sourceText: String) {
   private fun formatLetParameterDefinition(node: Node): FormatNode {
     val nodes =
       formatGeneric(node.children) { prev, next ->
-        if (prev.isTerminal("(")) null else if (next.isTerminal(")")) Line else SpaceOrLine
+        if (prev.isTerminal("(") || next.isTerminal(")")) Line else SpaceOrLine
       }
     return Group(newId(), nodes)
   }
diff --git a/pkl-formatter/src/test/files/FormatterSnippetTests/input/expr-let.pkl b/pkl-formatter/src/test/files/FormatterSnippetTests/input/expr-let.pkl
index 1cd0af5c..474c869c 100644
--- a/pkl-formatter/src/test/files/FormatterSnippetTests/input/expr-let.pkl
+++ b/pkl-formatter/src/test/files/FormatterSnippetTests/input/expr-let.pkl
@@ -9,3 +9,9 @@ baz =
   let (someVariable = 10000000)
     let (someOtherVariable = 2000000)
       let (someAnotherVariable = 3000000) someVariable + someOtherVariable + someAnotherVariable
+
+qux = let ( // some comment
+    // another comment
+    bar = 5
+  )
+    bar
diff --git a/pkl-formatter/src/test/files/FormatterSnippetTests/input/when.pkl b/pkl-formatter/src/test/files/FormatterSnippetTests/input/when.pkl
index 910fc445..f0a37ce4 100644
--- a/pkl-formatter/src/test/files/FormatterSnippetTests/input/when.pkl
+++ b/pkl-formatter/src/test/files/FormatterSnippetTests/input/when.pkl
@@ -7,3 +7,12 @@ foo {
     bar = 2
   }
 }
+
+bar {
+  when (new Listing {
+    1
+    2
+  }.contains(1)) {
+    "1"
+  }
+}
diff --git a/pkl-formatter/src/test/files/FormatterSnippetTests/output/expr-let.pkl b/pkl-formatter/src/test/files/FormatterSnippetTests/output/expr-let.pkl
index 838154a4..496477a9 100644
--- a/pkl-formatter/src/test/files/FormatterSnippetTests/output/expr-let.pkl
+++ b/pkl-formatter/src/test/files/FormatterSnippetTests/output/expr-let.pkl
@@ -1,11 +1,13 @@
 foo =
-  let (vaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaariable =
+  let (
+    vaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaariable =
       10
   )
     1 * 1
 
 bar =
-  let (someVariable = new Listing {
+  let (
+    someVariable = new Listing {
       1
     }
   )
@@ -16,3 +18,10 @@ baz =
   let (someOtherVariable = 2000000)
   let (someAnotherVariable = 3000000)
     someVariable + someOtherVariable + someAnotherVariable
+
+qux =
+  let ( // some comment
+    // another comment
+    bar = 5
+  )
+    bar
diff --git a/pkl-formatter/src/test/files/FormatterSnippetTests/output/when.pkl b/pkl-formatter/src/test/files/FormatterSnippetTests/output/when.pkl
index 2f0f6fd3..ce8b5ab9 100644
--- a/pkl-formatter/src/test/files/FormatterSnippetTests/output/when.pkl
+++ b/pkl-formatter/src/test/files/FormatterSnippetTests/output/when.pkl
@@ -5,3 +5,14 @@ foo {
     bar = 2
   }
 }
+
+bar {
+  when (
+    new Listing {
+      1
+      2
+    }.contains(1)
+  ) {
+    "1"
+  }
+}
diff --git a/pkl-parser/src/main/java/org/pkl/parser/GenericParser.java b/pkl-parser/src/main/java/org/pkl/parser/GenericParser.java
index 161024c4..2dec2210 100644
--- a/pkl-parser/src/main/java/org/pkl/parser/GenericParser.java
+++ b/pkl-parser/src/main/java/org/pkl/parser/GenericParser.java
@@ -864,8 +864,8 @@ public class GenericParser {
             ff(children);
             var paramDef = new ArrayList<Node>();
             expect(Token.LPAREN, paramDef, "unexpectedToken", "(");
-            ff(paramDef);
             var param = new ArrayList<Node>();
+            ff(param);
             param.add(parseParameter());
             ff(param);
             expect(Token.ASSIGN, param, "unexpectedToken", "=");