Add a unit test for transactions

 + a few small minor new assert in other tests

CMakeLists.txt

@@ -120,6 +120,7 @@ set(SQLITECPP_TESTS
  tests/Database_test.cpp
  tests/Statement_test.cpp
  tests/Backup_test.cpp
+ tests/Transaction_test.cpp
  tests/VariadicBind_test.cpp
 )
 source_group(tests FILES ${SQLITECPP_TESTS})

examples/example1/main.cpp

@@ -357,7 +357,7 @@ int main ()
             nb = db.exec("INSERT INTO test ObviousError");
             std::cout << "INSERT INTO test \"error\", returned " << nb << std::endl;
 
-            return EXIT_FAILURE; // unexpected success : exit the example program
+            return EXIT_FAILURE; // we should never get there : exit the example program
 
             // Commit transaction
             transaction.commit();

include/SQLiteCpp/Database.h

@@ -100,7 +100,7 @@ class Database
     /**
      * @brief Set a busy handler that sleeps for a specified amount of time when a table is locked.
      *
-     *  This is usefull in multithreaded program to handle case where a table is locked for writting by a thread.
+     *  This is useful in multithreaded program to handle case where a table is locked for writing by a thread.
      * Any other thread cannot access the table and will receive a SQLITE_BUSY error:
      * setting a timeout will wait and retry up to the time specified before returning this SQLITE_BUSY error.
      *  Reading the value of timeout for current connection can be done with SQL query "PRAGMA busy_timeout;".

tests/Column_test.cpp

@@ -40,10 +40,11 @@ TEST(Column, basis) {
     insert.bind(1, blob, size);
     // Execute the one-step query to insert the row
     EXPECT_EQ(1, insert.exec());
-
     EXPECT_EQ(1, db.getLastInsertRowid());
     EXPECT_EQ(1, db.getTotalChanges());
 
+    EXPECT_THROW(insert.exec(), SQLite::Exception); // exec() shall throw as it needs to be reseted
+
     // Compile a SQL query
     SQLite::Statement   query(db, "SELECT * FROM test");
     EXPECT_STREQ("SELECT * FROM test", query.getQuery().c_str());
@@ -166,4 +167,4 @@ TEST(Column, getName) {
     EXPECT_EQ("id",     oname0);
     EXPECT_EQ("msg",    oname1);
 #endif
-}
+}

tests/Statement_test.cpp

@@ -72,6 +72,8 @@ TEST(Statement, invalid) {
     EXPECT_THROW(query.isColumnNull(0), SQLite::Exception);
     EXPECT_THROW(query.getColumn(0), SQLite::Exception);
 
+    EXPECT_THROW(query.exec(), SQLite::Exception); // exec() shall throw as it needs to be reseted
+
     // Add a first row
     EXPECT_EQ(1, db.exec("INSERT INTO test VALUES (NULL, \"first\")"));
     EXPECT_EQ(1, db.getLastInsertRowid());

tests/Transaction_test.cpp

@@ -0,0 +1,77 @@
+/**
+ * @file    Transaction_test.cpp
+ * @ingroup tests
+ * @brief   Test of a SQLite Transaction.
+ *
+ * Copyright (c) 2012-2016 Sebastien Rombauts (sebastien.rombauts@gmail.com)
+ *
+ * Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
+ * or copy at http://opensource.org/licenses/MIT)
+ */
+
+#include <SQLiteCpp/Transaction.h>
+#include <SQLiteCpp/Database.h>
+#include <SQLiteCpp/Statement.h>
+#include <SQLiteCpp/Exception.h>
+
+#include <gtest/gtest.h>
+
+#include <cstdio>
+
+TEST(Transaction, commitRollback) {
+    // Create a new database
+    SQLite::Database db(":memory:", SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
+    EXPECT_EQ(SQLITE_OK, db.getErrorCode());
+
+    {
+        // Begin transaction
+        SQLite::Transaction transaction(db);
+
+        EXPECT_EQ(0, db.exec("CREATE TABLE test (id INTEGER PRIMARY KEY, value TEXT)"));
+        EXPECT_EQ(SQLITE_OK, db.getErrorCode());
+
+        // Insert a first value
+        EXPECT_EQ(1, db.exec("INSERT INTO test VALUES (NULL, \"first\")"));
+        EXPECT_EQ(1, db.getLastInsertRowid());
+
+        // Commit transaction
+        transaction.commit();
+
+        // Commit again throw an exception
+        EXPECT_THROW(transaction.commit(), SQLite::Exception);
+    }
+
+    // Auto rollback of a transaction on error
+    try
+    {
+        // Begin transaction
+        SQLite::Transaction transaction(db);
+
+        // Insert a second value (that will be rollbacked)
+        EXPECT_EQ(1, db.exec("INSERT INTO test VALUES (NULL, \"second\")"));
+        EXPECT_EQ(2, db.getLastInsertRowid());
+
+        // Execute with an error to rollback
+        db.exec("Obvious syntax error to raise an exception");
+        GTEST_FATAL_FAILURE_("we should never get there");
+
+        // Commit transaction
+        transaction.commit();
+    }
+    catch (std::exception& e)
+    {
+        std::cout << "SQLite exception: " << e.what() << std::endl;
+        // expected error, see above
+    }
+
+    // Check the results (expect only one row of result, as the second one has been rollbacked by the error)
+    SQLite::Statement query(db, "SELECT * FROM test");
+    int nbRows = 0;
+    while (query.executeStep())
+    {
+        nbRows++;
+        EXPECT_EQ(1, query.getColumn(0).getInt());
+        EXPECT_STREQ("first", query.getColumn(1).getText());
+    }
+    EXPECT_EQ(1, nbRows);
+}