Test eval if function with equal as condition

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalcitePPLConditionBuiltinFunctionIT.java

@@ -194,6 +194,19 @@ public void testIfWithLike() throws IOException {
         actual, rows(0.0, "John"), rows(0.0, "Jane"), rows(0.0, "Jake"), rows(1.0, "Hello"));
   }
 
+  @Test
+  public void testIfWithEquals() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval jake = if(name='Jake', 1, 0) | fields name, jake",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("jake", "int"));
+
+    verifyDataRows(actual, rows("Jake", 1), rows("Hello", 0), rows("John", 0), rows("Jane", 0));
+  }
+
   @Test
   public void testIsPresent() throws IOException {
     JSONObject actual =