From 227d095f2e7eb4dd732d7c215c444c1c10ccdef8 Mon Sep 17 00:00:00 2001
From: Riley Wilburn <riley@inngest.com>
Date: Thu, 22 Jan 2026 14:43:58 -0500
Subject: [PATCH] Fix CASE statement WHEN spacing

---
 parser/ast.go                                 |   5 +-
 .../format/select_case_multiple_when.sql      |  14 ++
 .../select_case_multiple_when.sql.golden.json | 153 ++++++++++++++++++
 .../query/select_case_multiple_when.sql       |   9 ++
 4 files changed, 180 insertions(+), 1 deletion(-)
 create mode 100644 parser/testdata/query/format/select_case_multiple_when.sql
 create mode 100644 parser/testdata/query/output/select_case_multiple_when.sql.golden.json
 create mode 100644 parser/testdata/query/select_case_multiple_when.sql

diff --git a/parser/ast.go b/parser/ast.go
index f2f63a3..7b76337 100644
--- a/parser/ast.go
+++ b/parser/ast.go
@@ -5444,7 +5444,10 @@ func (c *CaseExpr) String() string {
 	if c.Expr != nil {
 		builder.WriteString(c.Expr.String())
 	}
-	for _, when := range c.Whens {
+	for i, when := range c.Whens {
+		if i > 0 {
+			builder.WriteByte(' ')
+		}
 		builder.WriteString(when.String())
 	}
 	if c.Else != nil {
diff --git a/parser/testdata/query/format/select_case_multiple_when.sql b/parser/testdata/query/format/select_case_multiple_when.sql
new file mode 100644
index 0000000..c00c721
--- /dev/null
+++ b/parser/testdata/query/format/select_case_multiple_when.sql
@@ -0,0 +1,14 @@
+-- Origin SQL:
+SELECT
+    *,
+    CASE
+        WHEN col2 = 'value1' THEN 'when1'
+        WHEN col3 = 'value2' THEN 'when2'
+        ELSE 'else'
+    END as check_result
+FROM table_name
+WHERE col1 = '123456789'
+
+
+-- Format SQL:
+SELECT *, CASE WHEN col2 = 'value1' THEN 'when1' WHEN col3 = 'value2' THEN 'when2' ELSE 'else' END AS check_result FROM table_name WHERE col1 = '123456789';
diff --git a/parser/testdata/query/output/select_case_multiple_when.sql.golden.json b/parser/testdata/query/output/select_case_multiple_when.sql.golden.json
new file mode 100644
index 0000000..54fff72
--- /dev/null
+++ b/parser/testdata/query/output/select_case_multiple_when.sql.golden.json
@@ -0,0 +1,153 @@
+[
+  {
+    "SelectPos": 0,
+    "StatementEnd": 190,
+    "With": null,
+    "Top": null,
+    "HasDistinct": false,
+    "DistinctOn": null,
+    "SelectItems": [
+      {
+        "Expr": {
+          "Name": "*",
+          "QuoteType": 0,
+          "NamePos": 11,
+          "NameEnd": 11
+        },
+        "Modifiers": [],
+        "Alias": null
+      },
+      {
+        "Expr": {
+          "CasePos": 18,
+          "EndPos": 0,
+          "Expr": null,
+          "Whens": [
+            {
+              "WhenPos": 31,
+              "ThenPos": 52,
+              "When": {
+                "LeftExpr": {
+                  "Name": "col2",
+                  "QuoteType": 1,
+                  "NamePos": 36,
+                  "NameEnd": 40
+                },
+                "Operation": "=",
+                "RightExpr": {
+                  "LiteralPos": 44,
+                  "LiteralEnd": 50,
+                  "Literal": "value1"
+                },
+                "HasGlobal": false,
+                "HasNot": false
+              },
+              "Then": {
+                "LiteralPos": 58,
+                "LiteralEnd": 63,
+                "Literal": "when1"
+              },
+              "ElsePos": 0,
+              "Else": null
+            },
+            {
+              "WhenPos": 73,
+              "ThenPos": 94,
+              "When": {
+                "LeftExpr": {
+                  "Name": "col3",
+                  "QuoteType": 1,
+                  "NamePos": 78,
+                  "NameEnd": 82
+                },
+                "Operation": "=",
+                "RightExpr": {
+                  "LiteralPos": 86,
+                  "LiteralEnd": 92,
+                  "Literal": "value2"
+                },
+                "HasGlobal": false,
+                "HasNot": false
+              },
+              "Then": {
+                "LiteralPos": 100,
+                "LiteralEnd": 105,
+                "Literal": "when2"
+              },
+              "ElsePos": 0,
+              "Else": null
+            }
+          ],
+          "ElsePos": 115,
+          "Else": {
+            "LiteralPos": 121,
+            "LiteralEnd": 125,
+            "Literal": "else"
+          }
+        },
+        "Modifiers": [],
+        "Alias": {
+          "Name": "check_result",
+          "QuoteType": 1,
+          "NamePos": 138,
+          "NameEnd": 150
+        }
+      }
+    ],
+    "From": {
+      "FromPos": 151,
+      "Expr": {
+        "Table": {
+          "TablePos": 156,
+          "TableEnd": 166,
+          "Alias": null,
+          "Expr": {
+            "Database": null,
+            "Table": {
+              "Name": "table_name",
+              "QuoteType": 1,
+              "NamePos": 156,
+              "NameEnd": 166
+            }
+          },
+          "HasFinal": false
+        },
+        "StatementEnd": 166,
+        "SampleRatio": null,
+        "HasFinal": false
+      }
+    },
+    "Window": null,
+    "Prewhere": null,
+    "Where": {
+      "WherePos": 167,
+      "Expr": {
+        "LeftExpr": {
+          "Name": "col1",
+          "QuoteType": 1,
+          "NamePos": 173,
+          "NameEnd": 177
+        },
+        "Operation": "=",
+        "RightExpr": {
+          "LiteralPos": 181,
+          "LiteralEnd": 190,
+          "Literal": "123456789"
+        },
+        "HasGlobal": false,
+        "HasNot": false
+      }
+    },
+    "GroupBy": null,
+    "WithTotal": false,
+    "Having": null,
+    "OrderBy": null,
+    "LimitBy": null,
+    "Limit": null,
+    "Settings": null,
+    "Format": null,
+    "UnionAll": null,
+    "UnionDistinct": null,
+    "Except": null
+  }
+]
\ No newline at end of file
diff --git a/parser/testdata/query/select_case_multiple_when.sql b/parser/testdata/query/select_case_multiple_when.sql
new file mode 100644
index 0000000..f745b4a
--- /dev/null
+++ b/parser/testdata/query/select_case_multiple_when.sql
@@ -0,0 +1,9 @@
+SELECT
+    *,
+    CASE
+        WHEN col2 = 'value1' THEN 'when1'
+        WHEN col3 = 'value2' THEN 'when2'
+        ELSE 'else'
+    END as check_result
+FROM table_name
+WHERE col1 = '123456789'