[CALCITE-6014] Create a SqlOperatorFixture that parses, unparses, and…

… then parses again before executing

Signed-off-by: Mihai Budiu <[email protected]>

core/src/test/java/org/apache/calcite/test/SqlOperatorUnparseTest.java

@@ -0,0 +1,116 @@
+/*
+ * 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.calcite.test;
+
+import org.apache.calcite.sql.SqlNode;
+import org.apache.calcite.sql.parser.SqlParseException;
+import org.apache.calcite.sql.parser.SqlParser;
+import org.apache.calcite.sql.test.SqlOperatorFixture;
+import org.apache.calcite.sql.test.SqlTestFactory;
+
+import org.junit.jupiter.api.Disabled;
+
+import java.util.function.Consumer;
+import java.util.function.UnaryOperator;
+
+/**
+ * Version of a SqlOperatorTest which first parses and unparses
+ * the test program before executing it. Although similar to
+ * {@link org.apache.calcite.sql.parser.SqlUnParserTest},
+ * this test also validates the code after unparsing.
+ */
+@SuppressWarnings("JavadocReference")
+public class SqlOperatorUnparseTest extends CalciteSqlOperatorTest {
+  /** Fixture that runs an operator test after parsing and unparsing a query. */
+  static class SqlOperatorFixtureUnparseImpl extends SqlOperatorFixtureImpl {
+    SqlOperatorFixtureUnparseImpl(SqlTestFactory factory) {
+      super(factory, new UnparseTester(factory), false);
+    }
+
+    /**
+     * Retrieve the tester as an UnparseTester.  A downcast is needed because
+     * our tester implements a richer API than a regular SqlTester -- for example,
+     * it has a method withFactory.
+     */
+    UnparseTester getUnparseTester() {
+      return (UnparseTester) this.getTester();
+    }
+
+    public static final SqlOperatorFixtureImpl DEFAULT =
+        new SqlOperatorFixtureUnparseImpl(SqlTestFactory.INSTANCE);
+
+    @Override public SqlOperatorFixture withFactory(UnaryOperator<SqlTestFactory> transform) {
+      return super
+          .withFactory(transform)
+          // Pass the transform to the tester
+          .withTester(t -> this.getUnparseTester().withFactory(transform));
+    }
+  }
+
+  @Override protected SqlOperatorFixture fixture() {
+    return SqlOperatorFixtureUnparseImpl.DEFAULT;
+  }
+
+  /** A tester which parses, unparses, and then tests a query. */
+  static class UnparseTester extends TesterImpl {
+    public final SqlTestFactory factory;
+
+    UnparseTester(SqlTestFactory factory) {
+      this.factory = factory;
+    }
+
+    TesterImpl withFactory(UnaryOperator<SqlTestFactory> transform) {
+      return new UnparseTester(transform.apply(this.factory));
+    }
+
+    String rewrite(String sql) throws SqlParseException {
+      final SqlParser parser = factory.createParser(sql);
+      final SqlNode sqlNode = parser.parseStmt();
+      return sqlNode.toSqlString(c -> c).getSql();
+    }
+
+    @Override public void forEachQuery(
+        SqlTestFactory factory, String expression, Consumer<String> consumer) {
+      consumer.accept(buildQuery2(factory, expression));
+    }
+
+    @Override public void check(SqlTestFactory factory, String sql, TypeChecker typeChecker,
+        ParameterChecker parameterChecker, ResultChecker resultChecker) {
+      try {
+        String optQuery = this.rewrite(sql);
+        super.check(factory, optQuery, typeChecker, parameterChecker, resultChecker);
+      } catch (SqlParseException e) {
+        throw new RuntimeException(e);
+      }
+    }
+  }
+
+  // Every test that is Disabled below corresponds to a bug.
+  // These tests should just be deleted when the corresponding bugs are fixed.
+
+  @Override @Disabled("https://issues.apache.org/jira/browse/CALCITE-5998 "
+      + "The SAFE_OFFSET operator can cause an index out of bounds exception")
+  void testSafeOffsetOperator() {
+    super.testSafeOffsetOperator();
+  }
+
+  @Override @Disabled("https://issues.apache.org/jira/browse/CALCITE-6002 "
+      + "CONTAINS_SUBSTR does not unparse correctly")
+  void testContainsSubstrFunc() {
+    super.testContainsSubstrFunc();
+  }
+}

testkit/src/main/java/org/apache/calcite/test/SqlOperatorFixtureImpl.java

@@ -76,7 +76,7 @@ class SqlOperatorFixtureImpl implements SqlOperatorFixture {
     return tester;
   }
 
-  @Override public SqlOperatorFixtureImpl withFactory(
+  @Override public SqlOperatorFixture withFactory(
       UnaryOperator<SqlTestFactory> transform) {
     final SqlTestFactory factory = transform.apply(this.factory);
     if (factory == this.factory) {