From c3726a66334633856473dc6bc96edefd0c8c533a Mon Sep 17 00:00:00 2001
From: Pijus Kamandulis <pikami@users.noreply.github.com>
Date: Sat, 30 May 2026 17:43:05 +0300
Subject: [PATCH] Fix ARRAY_CONTAINS panic when optional partial-match argument
 is omitted (#14)

* Fix ARRAY_CONTAINS panic when partial match arg is omitted

The NoSQL parser always emits a third (nil) argument for the optional
partial-match flag of ARRAY_CONTAINS. The executor checked only
len(arguments) > 2 before type-asserting arguments[2] to
parsers.SelectItem, which panicked on the nil value whenever the query
omitted the partial-match argument (e.g. ARRAY_CONTAINS(c.arr, 2)).

Guard the type assertion with a nil check and add an API test covering
ARRAY_CONTAINS with and without the optional partial-match argument.

Co-authored-by: Pijus Kamandulis <pikami@users.noreply.github.com>

* Remove comments from ARRAY_CONTAINS API test

Co-authored-by: Pijus Kamandulis <pikami@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
---
 api/tests/documents_array_functions_test.go   | 47 +++++++++++++++++++
 .../memory_executor/array_functions.go        |  2 +-
 2 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 api/tests/documents_array_functions_test.go

diff --git a/api/tests/documents_array_functions_test.go b/api/tests/documents_array_functions_test.go
new file mode 100644
index 0000000..dd7c60a
--- /dev/null
+++ b/api/tests/documents_array_functions_test.go
@@ -0,0 +1,47 @@
+package tests_test
+
+import (
+	"testing"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/data/azcosmos"
+)
+
+func Test_Documents_ArrayContains(t *testing.T) {
+	presets := []testPreset{PresetJsonStore, PresetBadgerStore}
+
+	runTestsWithPresets(t, "Test_Documents_ArrayContains", presets, func(t *testing.T, ts *TestServer, client *azcosmos.Client) {
+		collectionClient := documents_InitializeDb(t, ts)
+
+		t.Run("Should execute ARRAY_CONTAINS() without partial match argument", func(t *testing.T) {
+			testCosmosQuery(t, collectionClient,
+				`SELECT VALUE ARRAY_CONTAINS(["apple", "banana", "cherry"], "banana") FROM c ORDER BY c.id`,
+				nil,
+				[]interface{}{true, true},
+			)
+		})
+
+		t.Run("Should execute ARRAY_CONTAINS() returning false for missing item", func(t *testing.T) {
+			testCosmosQuery(t, collectionClient,
+				`SELECT VALUE ARRAY_CONTAINS(["apple", "banana", "cherry"], "grape") FROM c ORDER BY c.id`,
+				nil,
+				[]interface{}{false, false},
+			)
+		})
+
+		t.Run("Should execute ARRAY_CONTAINS() with object full match", func(t *testing.T) {
+			testCosmosQuery(t, collectionClient,
+				`SELECT VALUE ARRAY_CONTAINS([{"name": "apple", "color": "red"}], {"name": "apple"}) FROM c ORDER BY c.id`,
+				nil,
+				[]interface{}{false, false},
+			)
+		})
+
+		t.Run("Should execute ARRAY_CONTAINS() with object partial match", func(t *testing.T) {
+			testCosmosQuery(t, collectionClient,
+				`SELECT VALUE ARRAY_CONTAINS([{"name": "apple", "color": "red"}], {"name": "apple"}, true) FROM c ORDER BY c.id`,
+				nil,
+				[]interface{}{true, true},
+			)
+		})
+	})
+}
diff --git a/query_executors/memory_executor/array_functions.go b/query_executors/memory_executor/array_functions.go
index 6d60517..48b18bf 100644
--- a/query_executors/memory_executor/array_functions.go
+++ b/query_executors/memory_executor/array_functions.go
@@ -25,7 +25,7 @@ func (r rowContext) array_Contains(arguments []interface{}) bool {
 	exprToSearch := r.resolveSelectItem(arguments[1].(parsers.SelectItem))
 
 	partialSearch := false
-	if len(arguments) > 2 {
+	if len(arguments) > 2 && arguments[2] != nil {
 		boolExpr := r.resolveSelectItem(arguments[2].(parsers.SelectItem))
 		if boolValue, ok := boolExpr.(bool); ok {
 			partialSearch = boolValue