Add test cases on SubqueryTableContextEngine (#33208)

infra/binder/src/test/java/org/apache/shardingsphere/infra/binder/context/segment/select/subquery/engine/SubqueryTableContextEngineTest.java

@@ -0,0 +1,100 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.infra.binder.context.segment.select.subquery.engine;
+
+import org.apache.shardingsphere.infra.binder.context.segment.select.projection.Projection;
+import org.apache.shardingsphere.infra.binder.context.segment.select.projection.impl.ColumnProjection;
+import org.apache.shardingsphere.infra.binder.context.segment.select.subquery.SubqueryTableContext;
+import org.apache.shardingsphere.infra.binder.context.statement.dml.SelectStatementContext;
+import org.apache.shardingsphere.infra.database.core.type.DatabaseType;
+import org.apache.shardingsphere.infra.spi.type.typed.TypedSPILoader;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.generic.table.JoinTableSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.generic.table.SimpleTableSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.generic.table.TableNameSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.value.identifier.IdentifierValue;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class SubqueryTableContextEngineTest {
+
+    private final DatabaseType databaseType = TypedSPILoader.getService(DatabaseType.class, "FIXTURE");
+
+    @Test
+    void assertCreateSubqueryTableContextsWithSimpleTableSegment() {
+        SelectStatementContext subqueryContext = mock(SelectStatementContext.class, RETURNS_DEEP_STUBS);
+        when(subqueryContext.getSqlStatement().getFrom()).thenReturn(Optional.of(new SimpleTableSegment(new TableNameSegment(0, 0, new IdentifierValue("foo_tbl")))));
+        ColumnProjection columnProjection = new ColumnProjection("o", "foo_col", "a", databaseType);
+        List<Projection> projections = Arrays.asList(mock(Projection.class), columnProjection);
+        when(subqueryContext.getProjectionsContext().getExpandProjections()).thenReturn(projections);
+        Map<String, SubqueryTableContext> actual = new SubqueryTableContextEngine().createSubqueryTableContexts(subqueryContext, "alias");
+        assertThat(actual.size(), is(1));
+        assertThat(actual.get("foo_tbl").getTableName(), is("foo_tbl"));
+        assertThat(actual.get("foo_tbl").getAliasName(), is("alias"));
+        assertThat(actual.get("foo_tbl").getColumnNames(), is(Collections.singletonList("foo_col")));
+    }
+
+    @Test
+    void assertCreateSubqueryTableContextsWithJoinTableSegmentAndPresentColumnOwner() {
+        SelectStatementContext subqueryContext = mock(SelectStatementContext.class, RETURNS_DEEP_STUBS);
+        when(subqueryContext.getTablesContext().getSimpleTables()).thenReturn(Collections.singleton(new SimpleTableSegment(new TableNameSegment(0, 0, new IdentifierValue("foo_tbl")))));
+        when(subqueryContext.getSqlStatement().getFrom()).thenReturn(Optional.of(mock(JoinTableSegment.class)));
+        ColumnProjection columnProjection = new ColumnProjection("foo_tbl", "foo_col", "a", databaseType);
+        List<Projection> projections = Arrays.asList(mock(Projection.class), columnProjection);
+        when(subqueryContext.getProjectionsContext().getExpandProjections()).thenReturn(projections);
+        Map<String, SubqueryTableContext> actual = new SubqueryTableContextEngine().createSubqueryTableContexts(subqueryContext, "alias");
+        assertThat(actual.size(), is(1));
+        assertThat(actual.get("foo_tbl").getTableName(), is("foo_tbl"));
+        assertThat(actual.get("foo_tbl").getAliasName(), is("alias"));
+        assertThat(actual.get("foo_tbl").getColumnNames(), is(Collections.singletonList("foo_col")));
+    }
+
+    @Test
+    void assertCreateSubqueryTableContextsWithJoinTableSegmentAndMisMatchedColumnOwner() {
+        SelectStatementContext subqueryContext = mock(SelectStatementContext.class, RETURNS_DEEP_STUBS);
+        when(subqueryContext.getTablesContext().getSimpleTables()).thenReturn(Collections.singleton(new SimpleTableSegment(new TableNameSegment(0, 0, new IdentifierValue("foo_tbl")))));
+        when(subqueryContext.getSqlStatement().getFrom()).thenReturn(Optional.of(mock(JoinTableSegment.class)));
+        ColumnProjection columnProjection = new ColumnProjection("o", "foo_col", "a", databaseType);
+        List<Projection> projections = Arrays.asList(mock(Projection.class), columnProjection);
+        when(subqueryContext.getProjectionsContext().getExpandProjections()).thenReturn(projections);
+        Map<String, SubqueryTableContext> actual = new SubqueryTableContextEngine().createSubqueryTableContexts(subqueryContext, "alias");
+        assertTrue(actual.isEmpty());
+    }
+
+    @Test
+    void assertCreateSubqueryTableContextsWithJoinTableSegmentAndAbsentColumnOwner() {
+        SelectStatementContext subqueryContext = mock(SelectStatementContext.class, RETURNS_DEEP_STUBS);
+        when(subqueryContext.getSqlStatement().getFrom()).thenReturn(Optional.of(mock(JoinTableSegment.class)));
+        ColumnProjection columnProjection = new ColumnProjection(null, "foo_col", "a", databaseType);
+        List<Projection> projections = Arrays.asList(mock(Projection.class), columnProjection);
+        when(subqueryContext.getProjectionsContext().getExpandProjections()).thenReturn(projections);
+        Map<String, SubqueryTableContext> actual = new SubqueryTableContextEngine().createSubqueryTableContexts(subqueryContext, "alias");
+        assertTrue(actual.isEmpty());
+    }
+}