Refactor LibraryBackendTest to make it easier to write tests.

tests/librarybackend_test.cpp

@@ -11,6 +11,7 @@
 #include <QThread>
 
 using ::testing::_;
+using ::testing::AtMost;
 using ::testing::Invoke;
 using ::testing::Return;
 
@@ -22,10 +23,12 @@ void PrintTo(const ::QString& str, std::ostream& os) {
 
 class LibraryBackendTest : public ::testing::Test {
  protected:
-  LibraryBackendTest() {
+  LibraryBackendTest()
+      : current_result_(0) {
   }
 
   virtual void SetUp() {
+    // Owned by QSqlDatabase.
     driver_ = new MockSqlDriver;
     // DB connect calls.
     EXPECT_CALL(*driver_, open(_, _, _, _, _, _)).WillOnce(Return(true));
@@ -60,17 +63,73 @@ class LibraryBackendTest : public ::testing::Test {
         reinterpret_cast<quint64>(QThread::currentThread())));
   }
 
+  // Call this to mock a single query with one row of results.
+  void ExpectQuery(const QString& query,
+                   const QList<QVariant>& bind_values,
+                   const QMap<QString, QVariant>& named_bind_values,
+                   const QList<QVariant>& columns) {
+    // Owned by QSqlDatabase.
+    current_result_ = new MockSqlResult(driver_);
+    EXPECT_CALL(*driver_, createResult()).
+        WillOnce(Return(current_result_));
+
+    // Query string is set.
+    EXPECT_CALL(*current_result_, reset(QString(query))).WillOnce(
+        DoAll(
+            Invoke(current_result_, &MockSqlResult::hackSetActive),
+            Return(true)));
+    // Query is executed.
+    EXPECT_CALL(*current_result_, exec()).WillOnce(Return(true));
+
+    // Values are bound.
+    for (int i = 0; i < bind_values.size(); ++i) {
+      ExpectBind(i, bind_values[i]);
+    }
+    for (QMap<QString, QVariant>::const_iterator it = named_bind_values.begin();
+         it != named_bind_values.end(); ++it) {
+      ExpectBind(it.key(), it.value());
+    }
+
+    // One row is fetched.
+    EXPECT_CALL(*current_result_, fetch(1)).WillOnce(
+        DoAll(
+            Invoke(current_result_, &MockSqlResult::setAt),
+            Return(true)));
+    // Tries to fetch second row but we say we do not have any more rows.
+    // Can be called 0-1 times. This catches the case where a query is only expected
+    // to have one row so QSqlQuery::next() is only called once.
+    EXPECT_CALL(*current_result_, fetch(2)).Times(AtMost(1)).WillOnce(Return(false));
+
+    // Expect data() calls for each column.
+    ExpectData(columns);
+  }
+
+  void ExpectBind(int index, const QVariant& value) {
+    EXPECT_CALL(*current_result_, bindValue(index, value, _));
+  }
+
+  void ExpectBind(const QString& bind, const QVariant& value) {
+    EXPECT_CALL(*current_result_, bindValue(bind, value, _));
+  }
+
+  void ExpectData(const QList<QVariant>& columns) {
+    for (int i = 0; i < columns.size(); ++i) {
+      EXPECT_CALL(*current_result_, data(i)).WillRepeatedly(
+          Return(columns[i])).RetiresOnSaturation();
+    }
+  }
+
   MockSqlDriver* driver_;
   scoped_ptr<LibraryBackend> backend_;
-};
 
-MATCHER(Printer, "") { qDebug() << arg; return true; }
+  MockSqlResult* current_result_;
+};
 
 TEST_F(LibraryBackendTest, DatabaseInitialises) {
 
 }
 
-TEST_F(LibraryBackendTest, GetSongs) {
+TEST_F(LibraryBackendTest, GetSongsSuccessfully) {
   const char* query =
       "SELECT ROWID, title, album, artist, albumartist, composer, "
       "track, disc, bpm, year, genre, comment, compilation, "
@@ -79,32 +138,44 @@ TEST_F(LibraryBackendTest, GetSongs) {
       " FROM songs "
       "WHERE (compilation = 0 AND sampler = 0) AND artist = ?"
       " AND album = ?";
-  MockSqlResult* result = new MockSqlResult(driver_);
-  EXPECT_CALL(*driver_, createResult()).
-      WillOnce(Return(result));
-  EXPECT_CALL(*result, reset(QString(query))).WillOnce(
-      DoAll(
-          Invoke(result, &MockSqlResult::hackSetActive),
-          Return(true)));
-
-  EXPECT_CALL(*result, bindValue(0, QVariant("foo"), _));
-  EXPECT_CALL(*result, bindValue(1, QVariant("bar"), _));
-
-  EXPECT_CALL(*result, exec()).WillOnce(Return(true));
-  EXPECT_CALL(*result, fetch(1)).WillOnce(
-      DoAll(
-          Invoke(result, &MockSqlResult::setAt),
-          Return(true)));
-  EXPECT_CALL(*result, fetch(2)).WillOnce(Return(false));
+  QList<QVariant> bind_values;
+  bind_values << "foo";
+  bind_values << "bar";
 
+  QList<QVariant> columns;
   for (int i = 0; i < 24; ++i) {
     // Fill every column with 42.
-    EXPECT_CALL(*result, data(i)).WillRepeatedly(
-        Return(QVariant(42))).RetiresOnSaturation();
+    columns << 42;
   }
 
+  ExpectQuery(query, bind_values, QMap<QString, QVariant>(), columns);
+
   SongList songs = backend_->GetSongs("foo", "bar");
   ASSERT_EQ(1, songs.length());
   EXPECT_EQ(42, songs[0].length());
   EXPECT_EQ(42, songs[0].id());
 }
+
+TEST_F(LibraryBackendTest, GetSongByIdSuccessfully) {
+  const char* query =
+      "SELECT ROWID, title, album, artist, albumartist, composer, "
+      "track, disc, bpm, year, genre, comment, compilation, "
+      "length, bitrate, samplerate, directory, filename, "
+      "mtime, ctime, filesize, sampler, art_automatic, art_manual"
+      " FROM songs "
+      "WHERE ROWID = :id";
+  QMap<QString, QVariant> bind_values;
+  bind_values[":id"] = 42;
+
+  QList<QVariant> columns;
+  for (int i = 0; i < 24; ++i) {
+    // Fill every column with 42.
+    columns << 42;
+  }
+
+  ExpectQuery(query, QList<QVariant>(), bind_values, columns);
+
+  Song song = backend_->GetSongById(42);
+  EXPECT_EQ(42, song.length());
+  EXPECT_EQ(42, song.id());
+}