porting query tests

datastore/sql/sqliteds.nim

@@ -163,58 +163,62 @@ proc query*(
     if not (v == SQLITE_OK):
       return failure newException(DatastoreError, $sqlite3_errstr(v))
 
-  let handle = DbQueryHandle()
-  let iter = iterator(): ?!DbQueryResponse {.closure.} =
-
-    try:
-      if handle.cancel:
-        return
-
-      let v = sqlite3_step(s)
-
-      case v
-      of SQLITE_ROW:
-        let
-          key = KeyId.new(sqlite3_column_text_not_null(s, QueryStmtIdCol))
-
-          blob: ?pointer =
-            if query.value: sqlite3_column_blob(s, QueryStmtDataCol).some
-            else: pointer.none
-
-        # detect out-of-memory error
-        # see the conversion table and final paragraph of:
-        # https://www.sqlite.org/c3ref/column_blob.html
-        # see also https://www.sqlite.org/rescode.html
-
-        # the "data" column can be NULL so in order to detect an out-of-memory
-        # error it is necessary to check that the result is a null pointer and
-        # that the result code is an error code
-        if blob.isSome and blob.get().isNil:
-          let v = sqlite3_errcode(sqlite3_db_handle(s))
-
-          if not (v in [SQLITE_OK, SQLITE_ROW, SQLITE_DONE]):
-            return failure newException(DatastoreError, $sqlite3_errstr(v))
-
-        let
-          dataLen = sqlite3_column_bytes(s, QueryStmtDataCol)
-          data =
-            if blob.isSome: DataBuffer.new(blob.get(), 0, dataLen - 1)
-            else: DataBuffer.new(0)
-
-        yield success (key.some, data)
-      of SQLITE_DONE:
-        return
-      else:
-        return failure newException(DatastoreError, $sqlite3_errstr(v))
-
-    finally:
+  proc doClose() =
       echo "sqlite backend: query: finally close"
       discard sqlite3_reset(s)
       discard sqlite3_clear_bindings(s)
       s.dispose()
       return
-  
-  success (handle, iter)
+
+  let handle = DbQueryHandle()
+  let iter = iterator(): ?!DbQueryResponse {.closure.} =
+
+    if handle.cancel:
+      doClose()
+      return
+
+    let v = sqlite3_step(s)
+
+    case v
+    of SQLITE_ROW:
+      echo "SQLITE ROW"
+      let
+        key = KeyId.new(sqlite3_column_text_not_null(s, QueryStmtIdCol))
+
+        blob: ?pointer =
+          if query.value: sqlite3_column_blob(s, QueryStmtDataCol).some
+          else: pointer.none
+
+      # detect out-of-memory error
+      # see the conversion table and final paragraph of:
+      # https://www.sqlite.org/c3ref/column_blob.html
+      # see also https://www.sqlite.org/rescode.html
+
+      # the "data" column can be NULL so in order to detect an out-of-memory
+      # error it is necessary to check that the result is a null pointer and
+      # that the result code is an error code
+      if blob.isSome and blob.get().isNil:
+        let v = sqlite3_errcode(sqlite3_db_handle(s))
+
+        if not (v in [SQLITE_OK, SQLITE_ROW, SQLITE_DONE]):
+          return failure newException(DatastoreError, $sqlite3_errstr(v))
+
+      let
+        dataLen = sqlite3_column_bytes(s, QueryStmtDataCol)
+        data =
+          if blob.isSome: DataBuffer.new(blob.get(), 0, dataLen - 1)
+          else: DataBuffer.new(0)
+
+      echo "SQLITE ROW: yield"
+      yield success (key.some, data)
+    of SQLITE_DONE:
+      echo "SQLITE DONE: return"
+      doClose()
+      return
+    else:
+      echo "SQLITE ERROR: return"
+      doClose()
+      return failure newException(DatastoreError, $sqlite3_errstr(v))
 
 
 proc contains*(self: SQLiteBackend, key: DbKey): bool =