Fix NPE in QueryAssertions

Before this change, NullPointerException was thrown in QueryAssertions when formatting error message for mismatched query results. If either the expected or the actual result contained a MaterializedRow having a null field, NPE was caused by calling `toString()` on null.
txn2 · Oct 16, 2020 · 36d2ab3 · 36d2ab3
1 parent e87933e
commit 36d2ab3
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Showing 2 changed files with 28 additions and 1 deletion.
diff --git a/presto-main/src/test/java/io/prestosql/sql/query/QueryAssertions.java b/presto-main/src/test/java/io/prestosql/sql/query/QueryAssertions.java
@@ -223,7 +223,7 @@ public String toStringOf(Object object)
                     MaterializedRow row = (MaterializedRow) object;
 
                     return row.getFields().stream()
-                            .map(Object::toString)
+                            .map(String::valueOf)
                             .collect(Collectors.joining(", ", "(", ")"));
                 }
                 else {

diff --git a/presto-tests/src/test/java/io/prestosql/tests/TestLocalQueryAssertions.java b/presto-tests/src/test/java/io/prestosql/tests/TestLocalQueryAssertions.java
@@ -16,6 +16,7 @@
 import io.prestosql.Session;
 import io.prestosql.testing.LocalQueryRunner;
 import io.prestosql.testing.QueryRunner;
+import org.testng.annotations.Test;
 
 import static io.airlift.testing.Closeables.closeAllSuppress;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -62,4 +63,30 @@ public void testIsFullyPushedDownWithSession()
                 .isInstanceOf(IllegalStateException.class)
                 .hasMessage("testIsFullyPushedDown() currently does not work with LocalQueryRunner");
     }
+
+    @Test
+    public void testNullInErrorMessage()
+    {
+        assertThatThrownBy(() -> assertThat(query("SELECT CAST(null AS integer)")).matches("SELECT 1"))
+                .hasMessage("[Rows] \n" +
+                        "Expecting:\n" +
+                        "  <(null)>\n" +
+                        "to contain exactly in any order:\n" +
+                        "  <[(1)]>\n" +
+                        "elements not found:\n" +
+                        "  <(1)>\n" +
+                        "and elements not expected:\n" +
+                        "  <(null)>\n");
+
+        assertThatThrownBy(() -> assertThat(query("SELECT 1")).matches("SELECT CAST(null AS integer)"))
+                .hasMessage("[Rows] \n" +
+                        "Expecting:\n" +
+                        "  <(1)>\n" +
+                        "to contain exactly in any order:\n" +
+                        "  <[(null)]>\n" +
+                        "elements not found:\n" +
+                        "  <(null)>\n" +
+                        "and elements not expected:\n" +
+                        "  <(1)>\n");
+    }
 }