From 149f11ad5cd56e61076077f2e08062e9a8f3ffc6 Mon Sep 17 00:00:00 2001
From: - <->
Date: Wed, 20 Oct 2021 18:08:31 +0200
Subject: [PATCH] 0.9: - Lib passes a SmlFrameSnippet to the builder

---
 src/smllib/__version__.py       |   2 +-
 src/smllib/builder/_builder.py  |   5 +-
 src/smllib/builder/message.py   |   5 +-
 src/smllib/sml/sml_choice.py    |   7 +-
 src/smllib/sml/sml_time.py      |  12 +-
 src/smllib/sml_frame.py         |  74 ++++++-----
 src/smllib/sml_frame_snippet.py |  17 +++
 tests/builder/test_build.py     |  14 +-
 tests/conftest.py               |   2 +-
 tests/helper.py                 |  13 ++
 tests/sml/test_format.py        |  18 +--
 tests/sml/test_time.py          |  13 +-
 tests/test_sml_data_types.py    | 218 ++++++++++++++++++++++++++++++++
 tests/test_sml_fields.py        |  14 +-
 tests/test_sml_frame.py         | 142 ---------------------
 15 files changed, 338 insertions(+), 218 deletions(-)
 create mode 100644 src/smllib/sml_frame_snippet.py
 create mode 100644 tests/helper.py
 create mode 100644 tests/test_sml_data_types.py
 delete mode 100644 tests/test_sml_frame.py

diff --git a/src/smllib/__version__.py b/src/smllib/__version__.py
index 376df7c..e46aee1 100644
--- a/src/smllib/__version__.py
+++ b/src/smllib/__version__.py
@@ -1 +1 @@
-__version__ = '0.8'
+__version__ = '0.9'
diff --git a/src/smllib/builder/_builder.py b/src/smllib/builder/_builder.py
index f644600..8343b69 100644
--- a/src/smllib/builder/_builder.py
+++ b/src/smllib/builder/_builder.py
@@ -13,13 +13,14 @@ def __init__(self):
 
     def build(self, obj: list, classes: Dict[Type[SmlBaseObj], 'SmlObjBuilder']) -> T_SML_OBJ:
         # check length
-        if len(self.fields) != len(obj):
+        lst = obj.value
+        if len(self.fields) != len(lst):
             raise WrongArgCount()
 
         out = self.BUILDS()
         for i, a in enumerate(self.fields.items()):   # type: int, Tuple[str, SmlObjFieldInfo]
             name, field = a
-            value = obj[i]
+            value = lst[i].value
 
             # rebuild with choice
             if field.choice is not None:
diff --git a/src/smllib/builder/message.py b/src/smllib/builder/message.py
index cce2e31..3e1e1c0 100644
--- a/src/smllib/builder/message.py
+++ b/src/smllib/builder/message.py
@@ -11,8 +11,9 @@ class SmlMessageBuilder(SmlObjBuilder):
     BUILDS = smllib.sml.SmlMessage
 
     def build(self, obj: list, classes: Dict[Type[SmlBaseObj], SmlObjBuilder]) -> smllib.sml.SmlMessage:
-        if obj[5] is not EndOfSmlMsg:
+        lst = obj.value
+        if lst[5].value is not EndOfSmlMsg:
             raise EndOfSmlMsgExpected()
-        obj.pop(5)
+        lst.pop(5)
 
         return super().build(obj, classes)
diff --git a/src/smllib/sml/sml_choice.py b/src/smllib/sml/sml_choice.py
index 8c252e4..609b9a7 100644
--- a/src/smllib/sml/sml_choice.py
+++ b/src/smllib/sml/sml_choice.py
@@ -2,20 +2,21 @@
 
 from smllib.errors import UnsupportedType, WrongArgCount
 from smllib.sml import SmlBaseObj
+from smllib.sml_frame_snippet import SmlFrameSnippet
 
 
 class SmlChoice:
     def __init__(self, choices: Dict[int, Union[Type[SmlBaseObj], Callable[[List[Any]], Any]]]):
         self.choices = choices
 
-    def get(self, obj) -> Union[Tuple[None, Any], Tuple[Type[SmlBaseObj], Any]]:
+    def get(self, obj: List[SmlFrameSnippet]) -> Union[Tuple[None, Any], Tuple[Type[SmlBaseObj], Any]]:
         if len(obj) != 2:
             raise WrongArgCount()
 
         _type, _value = obj
-        ret = self.choices.get(_type)
+        ret = self.choices.get(_type.value)
         if ret is None:
-            raise UnsupportedType(_type)
+            raise UnsupportedType(_type.value)
 
         if issubclass(ret, SmlBaseObj):
             return ret, _value
diff --git a/src/smllib/sml/sml_time.py b/src/smllib/sml/sml_time.py
index d4adebf..880505c 100644
--- a/src/smllib/sml/sml_time.py
+++ b/src/smllib/sml/sml_time.py
@@ -12,17 +12,17 @@ def build_time(_in):
 
     # This is a workaround for times that are not reported according to specification
     # Instead of a choice list these devices report just the timestamp - however I am unsure about it.
-    # todo: remove it and see what happens
     if isinstance(_in, int):
         return _in
 
-    _type, _value = _in
+    type_s, value_s = _in
+    _type = type_s.value
     if _type == 1:
-        return _value
+        return value_s.value
     if _type == 2:
-        return datetime.utcfromtimestamp(_value)
+        return datetime.utcfromtimestamp(value_s.value)
     if _type == 3:
-        ts, offset1, offset2 = _value
-        return datetime.utcfromtimestamp(ts) + timedelta(minutes=offset1) + timedelta(minutes=offset2)
+        ts, offset1, offset2 = value_s.value
+        return datetime.utcfromtimestamp(ts.value) + timedelta(minutes=offset1.value) + timedelta(minutes=offset2.value)
 
     raise UnsupportedType(_type)
diff --git a/src/smllib/sml_frame.py b/src/smllib/sml_frame.py
index 062929d..8c733cc 100644
--- a/src/smllib/sml_frame.py
+++ b/src/smllib/sml_frame.py
@@ -3,6 +3,7 @@
 from smllib.builder import create_context, CTX_HINT
 from smllib.errors import InvalidBufferPos
 from smllib.sml import EndOfSmlMsg, SmlListEntry, SmlMessage
+from smllib.sml_frame_snippet import SmlFrameSnippet
 
 
 class SmlFrame:
@@ -13,65 +14,74 @@ def __init__(self, buffer: bytes, build_ctx: CTX_HINT = None, msg_ctx: Optional[
 
         self.next_pos = 0
 
-        self.msg_ctx = msg_ctx
+        self.msg_ctx = msg_ctx  # This is the whole sml message
         self.build_ctx: CTX_HINT = build_ctx if build_ctx is not None else create_context()
 
-    def get_value(self, pos: Optional[int] = None):
+    def get_value(self, pos: Optional[int] = None) -> SmlFrameSnippet:
         if pos is None:
             pos = self.next_pos
+        snip_start = pos
 
         # check start pos
         if pos >= self.buf_len:
             raise InvalidBufferPos(f'Start pos bigger than buffer: {pos} > {self.buf_len}')
 
+        # advance
         v = self.buffer[pos]
+        start = pos + 1
+
+        # ----------------------------------------
+        # types with fixed size
+        # ----------------------------------------
 
         # No value
         if v == 0x01:
-            self.next_pos = pos + 1
-            return None
-
-        # Bool
-        if v == 0x42:
-            self.next_pos = pos + 2
-            return bool(self.buffer[pos + 1])
+            self.next_pos = start
+            return SmlFrameSnippet(None, snip_start, start, self.buffer)
 
         # End of a SmlMSg
         if v == 0x00:
-            self.next_pos = pos + 1
-            return EndOfSmlMsg
+            self.next_pos = start
+            return SmlFrameSnippet(EndOfSmlMsg, snip_start, start, self.buffer)
+
+        # Bool
+        if v == 0x42:
+            self.next_pos = start + 1
+            return SmlFrameSnippet(bool(self.buffer[start]), snip_start, self.next_pos, self.buffer)
 
+        # ----------------------------------------
         # types with dynamic size
-        s_pos = pos
+        # ----------------------------------------
         is_long = bool(v & 0x80)
         _type = v & 0x70  # type
         _size = v & 0x0F  # size including the 1-byte tag
         while is_long:
-            s_pos += 1
-            v = self.buffer[s_pos]
+            v = self.buffer[start]
             _size = _size << 4 | v & 0x0F
             is_long = bool(v & 0x80)
+            start += 1
 
         # type is a list
         if _type == 0x70:
-            self.next_pos = s_pos + 1   # Must be s_pos because we can have lists with a long length
-            return [None for _ in range(_size)]
+            self.next_pos = start   # Must be s_pos because we can have lists with a long length
+            return SmlFrameSnippet([None for _ in range(_size)], snip_start)
 
         # End position
-        e_pos = pos + _size
-        if e_pos > self.buf_len:
-            raise InvalidBufferPos(f'Pos bigger than buffer: {e_pos} > {self.buf_len}')
-        self.next_pos = e_pos
+        end = pos + _size
+        if end > self.buf_len:
+            raise InvalidBufferPos(f'Pos bigger than buffer: {end} > {self.buf_len}')
+        self.next_pos = end
 
         # 0x50: signed integer, 0x60 unsigned integer
-        if _type in (0x50, 0x60):
-            return int.from_bytes(
-                self.buffer[s_pos + 1:e_pos], byteorder='big', signed=True if _type == 0x50 else False
+        if _type == 0x50 or _type == 0x60:
+            return SmlFrameSnippet(
+                int.from_bytes(self.buffer[start:end], byteorder='big', signed=_type == 0x50),
+                snip_start, end, self.buffer
             )
 
         # 0x00: octet str
         if _type == 0x00:
-            return self.buffer[s_pos + 1:e_pos].hex()
+            return SmlFrameSnippet(self.buffer[start:end].hex(), snip_start, end, self.buffer)
 
         raise ValueError(f'Unknown data type: {_type:02x}!')
 
@@ -87,17 +97,19 @@ def parse_frame(self) -> List[SmlMessage]:
                 )
 
             # This will always return a list
-            val = self.get_value()
-            self._parse_msg(val)
+            val = self._parse_msg(self.get_value())
             ret.append(self.build_ctx[SmlMessage].build(val, self.build_ctx))
         return ret
 
-    def _parse_msg(self, parent_obj=None):
+    def _parse_msg(self, parent_obj: SmlFrameSnippet) -> SmlFrameSnippet:
         # it's always a list now
-        for i, _ in enumerate(parent_obj):
-            parent_obj[i] = v = self.get_value()
-            if isinstance(v, list):
+        _lst = parent_obj.value
+        for i, _ in enumerate(_lst):
+            _lst[i] = v = self.get_value()
+            if isinstance(v.value, list):
                 self._parse_msg(v)
+        parent_obj.stop_pos(self.next_pos, self.buffer)
+        return parent_obj
 
     def get_obis(self) -> List[SmlListEntry]:
         """Returns all obis values in the frame without parsing the frame"""
@@ -105,7 +117,7 @@ def get_obis(self) -> List[SmlListEntry]:
         start = -1
         while (start := self.bytes.find(b'\x77\x07\x01', start + 1)) != -1:
             data = self.get_value(start)
-            if not isinstance(data, list):
+            if not isinstance(data.value, list):
                 continue
 
             self._parse_msg(data)
diff --git a/src/smllib/sml_frame_snippet.py b/src/smllib/sml_frame_snippet.py
new file mode 100644
index 0000000..f43e863
--- /dev/null
+++ b/src/smllib/sml_frame_snippet.py
@@ -0,0 +1,17 @@
+from typing import Optional, Union
+
+
+class SmlFrameSnippet:
+    __slots__ = ('pos', 'value', 'msg')
+
+    def __init__(self, value: Union[None, bool, int, str, float, list], start: int,
+                 stop: Optional[int] = None, buf: Optional[memoryview] = None):
+        self.value = value
+
+        self.pos = start
+        self.msg: Optional[memoryview] = None if stop is None else buf[start: stop]
+
+    def stop_pos(self, pos: int, buf: memoryview) -> 'SmlFrameSnippet':
+        assert self.msg is None
+        self.msg = buf[self.pos: pos]
+        return self
diff --git a/tests/builder/test_build.py b/tests/builder/test_build.py
index cba8bec..e9158cd 100644
--- a/tests/builder/test_build.py
+++ b/tests/builder/test_build.py
@@ -1,21 +1,22 @@
 from smllib.builder import SmlCloseResponseBuilder, SmlGetListResponseBuilder, \
     SmlListEntryBuilder, SmlMessageBuilder, SmlObjBuilder
 from smllib.sml import EndOfSmlMsg, SmlCloseResponse, SmlGetListResponse, SmlListEntry
+from tests.helper import in_snip
 
 
 def test_build_entry():
     builder = SmlListEntryBuilder()
-    obj = builder.build(['obis', None, None, None, None, '76616c', None], {SmlListEntry: builder})
+    obj = builder.build(in_snip(['obis', None, None, None, None, '76616c', None]), {SmlListEntry: builder})
     assert obj.obis == 'obis'
     assert obj.value == 'val'
 
 
 def test_build_entry_list():
-    data = [
+    data = in_snip([
         None, 'server', None, None,
         [['obis1', None, None, None, None, '76616c31', None], ['obis2', None, None, None, None, '76616c32', None]],
         None, None
-    ]
+    ])
 
     builder = SmlGetListResponseBuilder()
 
@@ -43,9 +44,9 @@ def build(self, obj: list, classes):
 
 
 def test_build_choice():
+    data = in_snip(['t1', 1, 0, [0x0201, ['sig']], 1111, EndOfSmlMsg])
     builder = SmlMessageBuilder()
-    obj = builder.build(['t1', 1, 0, [0x0201, ['sig']], 1111, EndOfSmlMsg],
-                        {SmlCloseResponse: SmlCloseResponseBuilder()})
+    obj = builder.build(data, {SmlCloseResponse: SmlCloseResponseBuilder()})
     assert obj.transaction_id == 't1'
     assert obj.group_no == 1
     assert obj.abort_on_error == 0
@@ -61,7 +62,8 @@ def build(self, obj: list, classes):
             ret.global_signature += '_patched'
             return ret
 
-    obj = builder.build(['t1', 1, 0, [0x0201, ['sig']], 1111, EndOfSmlMsg], {SmlCloseResponse: PatchedBuilder()})
+    data = in_snip(['t1', 1, 0, [0x0201, ['sig']], 1111, EndOfSmlMsg])
+    obj = builder.build(data, {SmlCloseResponse: PatchedBuilder()})
     assert obj.transaction_id == 't1'
     assert obj.group_no == 1
     assert obj.abort_on_error == 0
diff --git a/tests/conftest.py b/tests/conftest.py
index e13dec1..bbd8045 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,7 +1,7 @@
 import sys
 from pathlib import Path
 
-# add src dir so tests  work
+# add src dir so tests work
 src = Path(__file__).parent.with_name('src')
 assert src.is_dir(), src
 if str(src) not in sys.path:
diff --git a/tests/helper.py b/tests/helper.py
new file mode 100644
index 0000000..3c4a53e
--- /dev/null
+++ b/tests/helper.py
@@ -0,0 +1,13 @@
+from smllib.sml_frame import SmlFrameSnippet
+
+
+def in_snip(obj, pack_top = True) -> SmlFrameSnippet:
+    if not isinstance(obj, (list, tuple)):
+        return SmlFrameSnippet(obj, 'from in_snip')
+
+    for i, k in enumerate(obj):
+        obj[i] = in_snip(k)
+
+    if pack_top:
+        return SmlFrameSnippet(obj, 'from in_snip')
+    return obj
diff --git a/tests/sml/test_format.py b/tests/sml/test_format.py
index 5d537cc..a1a47ca 100644
--- a/tests/sml/test_format.py
+++ b/tests/sml/test_format.py
@@ -1,9 +1,11 @@
-from smllib.sml import SmlOpenResponse, SmlCloseResponse, SmlGetListResponse, SmlListEntry, SmlMessage
-from smllib.builder import SmlOpenResponseBuilder, SmlCloseResponseBuilder, SmlGetListResponseBuilder, SmlListEntryBuilder, SmlMessageBuilder
+from smllib.builder import SmlCloseResponseBuilder, \
+    SmlGetListResponseBuilder, SmlListEntryBuilder, SmlOpenResponseBuilder
+from smllib.sml import SmlListEntry
+from tests.helper import in_snip
 
 
 def test_open_response():
-    r = SmlOpenResponseBuilder().build([None, None, 'ab', 'cd', None, 1], {})
+    r = SmlOpenResponseBuilder().build(in_snip([None, None, 'ab', 'cd', None, 1]), {})
     assert r.format_msg() == '<SmlOpenResponse>\n' \
                              '  codepage   : None\n' \
                              '  client_id  : None\n' \
@@ -14,21 +16,21 @@ def test_open_response():
 
 
 def test_close_response():
-    r = SmlCloseResponseBuilder().build(['my_sig'], {})
+    r = SmlCloseResponseBuilder().build(in_snip(['my_sig']), {})
     assert r.format_msg() == '<SmlCloseResponse>\n' \
                              '  global_signature: my_sig\n'
 
 
 def test_list_entry():
-    data = [
+    data = in_snip([
         None, 'server', None, None,
         [['obis1', None, None, None, None, '76616c31', None], ['obis2', None, None, None, None, '76616c32', None]],
         None, None
-    ]
-    
+    ])
+
     builder = SmlGetListResponseBuilder()
     obj = builder.build(data, {SmlListEntry: SmlListEntryBuilder()})
-    
+
     assert obj.format_msg() == '<SmlGetListResponse>\n' \
                                '  client_id       : None\n' \
                                '  sever_id        : server\n' \
diff --git a/tests/sml/test_time.py b/tests/sml/test_time.py
index cb626f8..be5051d 100644
--- a/tests/sml/test_time.py
+++ b/tests/sml/test_time.py
@@ -4,20 +4,21 @@
 
 from smllib.errors import UnsupportedType
 from smllib.sml.sml_time import build_time
+from tests.helper import in_snip
 
 
 def test_sml_time():
     assert build_time(None) is None
-    assert build_time([1, 253]) == 253
-    assert build_time([2, 1609466461]) == datetime(2021, 1, 1, 2, 1, 1)
+    assert build_time(in_snip([1, 253], pack_top=False)) == 253
+    assert build_time(in_snip([2, 1609466461], pack_top=False)) == datetime(2021, 1, 1, 2, 1, 1)
 
-    assert build_time([3, [1609466461, 120,  0]]) == datetime(2021, 1, 1, 4, 1, 1)
-    assert build_time([3, [1622509261, 120, 60]]) == datetime(2021, 6, 1, 4, 1, 1)
-    assert build_time([3, [1622509261, 120, 30]]) == datetime(2021, 6, 1, 3, 31, 1)
+    assert build_time(in_snip([3, [1609466461, 120,  0]], pack_top=False)) == datetime(2021, 1, 1, 4, 1, 1)
+    assert build_time(in_snip([3, [1622509261, 120, 60]], pack_top=False)) == datetime(2021, 6, 1, 4, 1, 1)
+    assert build_time(in_snip([3, [1622509261, 120, 30]], pack_top=False)) == datetime(2021, 6, 1, 3, 31, 1)
 
 
 def test_exception():
     with pytest.raises(UnsupportedType) as e:
-        build_time([5, 55])
+        build_time([in_snip(5), in_snip(55)])
     assert e.value.type == 5
     assert str(e.value) == 'Unsupported type 0x05'
diff --git a/tests/test_sml_data_types.py b/tests/test_sml_data_types.py
new file mode 100644
index 0000000..a45aea3
--- /dev/null
+++ b/tests/test_sml_data_types.py
@@ -0,0 +1,218 @@
+from binascii import a2b_hex
+
+from smllib.sml_frame import EndOfSmlMsg, SmlFrame, SmlFrameSnippet
+
+
+def check(f: SmlFrameSnippet, value, msg: str):
+    if value is True or value is False or value is None or value is EndOfSmlMsg:
+        assert f.value is value
+    else:
+        if isinstance(value, (tuple, list)):
+            for i, _value in enumerate(value):
+                assert f.value[i].value == _value
+        else:
+            assert f.value == value
+    assert f.msg.hex() == msg
+
+
+def test_get_int8():
+    f = SmlFrame(b'\x52\xff')
+    check(f.get_value(0), -1, '52ff')
+    assert f.next_pos == 2
+
+    f = SmlFrame(b'\x52\x03')
+    check(f.get_value(0), 3, '5203')
+    assert f.next_pos == 2
+
+    f = SmlFrame(b'\x00\x52\x03')
+    f.next_pos = 9999
+    check(f.get_value(1), 3, '5203')
+    assert f.next_pos == 3
+
+
+def test_get_uint8():
+    f = SmlFrame(b'\x62\xff')
+    check(f.get_value(0), 255, '62ff')
+    assert f.next_pos == 2
+
+    f = SmlFrame(b'\x62\x03')
+    check(f.get_value(0), 3, '6203')
+    assert f.next_pos == 2
+
+    f = SmlFrame(b'\x00\x62\xff')
+    f.next_pos = 9999
+    check(f.get_value(1), 255, '62ff')
+    assert f.next_pos == 3
+
+
+def test_get_int16():
+    f = SmlFrame(b'\x53\xff\x00')
+    check(f.get_value(0), -256, '53ff00')
+    assert f.next_pos == 3
+
+    f = SmlFrame(b'\x53\x00\x03')
+    check(f.get_value(0), 3, '530003')
+    assert f.next_pos == 3
+
+    f = SmlFrame(b'\x00\x53\xff\x01')
+    f.next_pos = 9999
+    check(f.get_value(1), -255, '53ff01')
+    assert f.next_pos == 4
+
+
+def test_get_uint16():
+    f = SmlFrame(b'\x63\xff\x00')
+    check(f.get_value(0), 65280, '63ff00')
+    assert f.next_pos == 3
+
+    f = SmlFrame(b'\x63\x00\x03')
+    check(f.get_value(0), 3, '630003')
+    assert f.next_pos == 3
+
+    f = SmlFrame(b'\x00\x63\xff\x01')
+    f.next_pos = 9999
+    check(f.get_value(1), 65281, '63ff01')
+    assert f.next_pos == 4
+
+
+def test_get_int32():
+    f = SmlFrame(b'\x55\x00\x00\x0a\x8c')
+    check(f.get_value(0), 2700, '5500000a8c')
+    assert f.next_pos == 5
+
+    f = SmlFrame(b'\x01\x01\x55\x00\x00\x0a\x8c')
+    f.next_pos = 9999
+    check(f.get_value(2), 2700, '5500000a8c')
+    assert f.next_pos == 7
+
+
+def test_get_uint32():
+    f = SmlFrame(b'\x55\x00\x00\x0a\x8c')
+    check(f.get_value(0), 2700, '5500000a8c')
+    assert f.next_pos == 5
+
+
+# def test_int():
+#
+#     f = SmlFrame(b'\x65\x0c\x6a\x50\xb5')
+#     assert f.get_value(0) == 208294069
+#
+#     # too short stuff
+#     with pytest.raises(InvalidBufferPos):
+#         f = SmlFrame(b'\x56\x00\x04\xeb\x09')
+#         assert f.get_value(0) is None
+#     with pytest.raises(InvalidBufferPos):
+#         f = SmlFrame(b'\x65\x0c\x6a')
+#         assert f.get_value(0) is None
+#
+#     # now with indexes > 0
+#     f = SmlFrame(b'\xaa\xbb\x56\x00\x04\xeb\x09\x6c')
+#     assert f.get_value(2) == 82512236
+#     f = SmlFrame(b'\x00\x52\xff')
+#     assert f.get_value(1) == -1
+#     f = SmlFrame(b'\x01\xff\x33\x62\x1e')
+#     assert f.get_value(3) == 30
+#     f = SmlFrame(b'\xab\xcd\x87\x44\x65\x0c\x6a\x50\xb5')
+#     assert f.get_value(4) == 208294069
+#
+#     # now with stuff appended
+#     f = SmlFrame(b'\x56\x00\x04\xeb\x09\x6c\x12\x34')
+#     assert f.get_value(0) == 82512236
+#     f = SmlFrame(b'\xaa\xbb\x52\xff\xcc\xdd')
+#     assert f.get_value(2) == -1
+#     f = SmlFrame(b'\x52\x62\x1e\x99')
+#     assert f.get_value(1) == 30
+#     f = SmlFrame(b'\x65\x0c\x6a\x50\xb5\x77\x88')
+#     assert f.get_value(0) == 208294069
+#
+#     # first some values starting at index 0
+#     f = SmlFrame(b'\x56\x00\x04\xeb\x09\x6c')
+#     assert check(f.get_value(0), 82512236, '5600')
+#
+
+def test_none():
+    f = SmlFrame(b'\x01\x01\x01')
+    assert f.get_value().value is None
+    assert f.next_pos == 1
+
+    f.next_pos = 9999
+    assert f.get_value(1).value is None
+    assert f.next_pos == 2
+
+    assert f.get_value().value is None
+    assert f.next_pos == 3
+
+
+def test_get_list():
+    f = SmlFrame(b'\x71\x01')
+    f.next_pos = 9999
+    check(f._parse_msg(f.get_value(0)), [None], '7101')
+    assert f.next_pos == 2
+
+    f = SmlFrame(b'\x72\x01\x00')
+    f.next_pos = 9999
+    check(f._parse_msg(f.get_value(0)), [None, EndOfSmlMsg], '720100')
+    assert f.next_pos == 3
+
+    f = SmlFrame(b'\x72\x52\xff\x62\x1e')
+    check(f._parse_msg(f.get_value(0)), [-1, 30], '7252ff621e')
+    assert f.next_pos == 5
+
+    f = SmlFrame(a2b_hex(
+        '77070100010800ff'
+        '6500000782'
+        '01'
+        '621e'
+        '52ff'
+        '59000000000dd359d6'
+        '01'
+        'ff'))
+    check(f._parse_msg(f.get_value(0)),
+          ['0100010800ff', 1922, None, 30, -1, 231954902, None],
+          '77070100010800ff650000078201621e52ff59000000000dd359d601')
+    assert f.next_pos == 28
+
+
+def test_str():
+    f = SmlFrame(b'\x07\x01\x00\x01\x08\x00\xFF')
+    f.next_pos = 9999
+    check(f.get_value(0), '0100010800ff', '070100010800ff')
+    assert f.next_pos == 7
+
+
+def test_long_str():
+    f = SmlFrame(a2b_hex('8302010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102'))  # noqa: E501
+    check(
+        f.get_value(0),
+        '010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102',
+        '8302010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102')
+    assert f.next_pos == 50
+
+    f = SmlFrame(a2b_hex('8302010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102FF'))  # noqa: E501
+    check(
+        f.get_value(0),
+        '010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102',
+        '8302010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102')
+    assert f.next_pos == 50
+    assert f.buffer[f.next_pos] == 0xFF
+
+
+def test_bool():
+    f = SmlFrame(b'\x42\x01')
+    f.next_pos = 9999
+    check(f.get_value(0), True, '4201')
+    assert f.next_pos == 2
+
+    f = SmlFrame(b'\x42\x00')
+    check(f.get_value(0), False, '4200')
+    assert f.next_pos == 2
+
+
+def test_eom():
+    f = SmlFrame(b'\x00')
+    check(f.get_value(0), EndOfSmlMsg, '00')
+    assert f.next_pos == 1
+
+    f = SmlFrame(b'\x00\x00')
+    check(f.get_value(1), EndOfSmlMsg, '00')
+    assert f.next_pos == 2
diff --git a/tests/test_sml_fields.py b/tests/test_sml_fields.py
index 09dca6a..fb2ba4b 100644
--- a/tests/test_sml_fields.py
+++ b/tests/test_sml_fields.py
@@ -6,17 +6,13 @@
 
 def test_sml_fields():
     f = SmlFrame(a2b_hex('77078181c78203ff010101010449534b0177070100000009ff010101010b'))
-    val_list = f.get_value(0)
-    for i, _ in enumerate(val_list):
-        val_list[i] = f.get_value()
+    val_list = f._parse_msg(f.get_value(0))
     o = SmlListEntryBuilder().build(val_list, create_context())
     assert o.obis == '8181c78203ff'
     assert o.value == 'ISK'
 
     f = SmlFrame(a2b_hex('77070100010800ff650000018201621e52ff590000000001122334017707'))
-    val_list = f.get_value(0)
-    for i, _ in enumerate(val_list):
-        val_list[i] = f.get_value()
+    val_list = f._parse_msg(f.get_value(0))
     o = SmlListEntryBuilder().build(val_list, create_context())
 
     assert o.obis == '0100010800ff'
@@ -30,15 +26,13 @@ def test_sml_fields():
 def test_val_time():
     # Frame where time is None
     f = SmlFrame(a2b_hex('77070100600100ff010101010b0a01484c5902000424a001'))
-    val_list = f.get_value(0)
-    f._parse_msg(val_list)
+    val_list = f._parse_msg(f.get_value(0))
     o = SmlListEntryBuilder().build(val_list, create_context())
     assert o.val_time is None
 
     # Frame where secIndex == 1 and time == 0
     # -> 7262016200
     f = SmlFrame(a2b_hex('77070100600100ff017262016200620052000b0a01445a47000282c0b001'))
-    val_list = f.get_value(0)
-    f._parse_msg(val_list)
+    val_list = f._parse_msg(f.get_value(0))
     o = SmlListEntryBuilder().build(val_list, create_context())
     assert o.val_time == 0
diff --git a/tests/test_sml_frame.py b/tests/test_sml_frame.py
deleted file mode 100644
index 407c468..0000000
--- a/tests/test_sml_frame.py
+++ /dev/null
@@ -1,142 +0,0 @@
-from binascii import a2b_hex
-
-import pytest
-
-from smllib.sml_frame import InvalidBufferPos, SmlFrame
-
-
-def test_get_int():
-
-    # first some values starting at index 0
-    f = SmlFrame(b'\x56\x00\x04\xeb\x09\x6c')
-    assert f.get_value(0) == 82512236
-
-    f = SmlFrame(b'\x52\xff')
-    assert f.get_value(0) == -1
-
-    f = SmlFrame(b'\x52\x03')
-    assert f.get_value(0) == 3
-
-    f = SmlFrame(b'\x62\x1e')
-    assert f.get_value(0) == 30
-
-    f = SmlFrame(b'\x65\x0c\x6a\x50\xb5')
-    assert f.get_value(0) == 208294069
-
-    # too short stuff
-    with pytest.raises(InvalidBufferPos):
-        f = SmlFrame(b'\x56\x00\x04\xeb\x09')
-        assert f.get_value(0) is None
-    with pytest.raises(InvalidBufferPos):
-        f = SmlFrame(b'\x65\x0c\x6a')
-        assert f.get_value(0) is None
-
-    # now with indexes > 0
-    f = SmlFrame(b'\xaa\xbb\x56\x00\x04\xeb\x09\x6c')
-    assert f.get_value(2) == 82512236
-    f = SmlFrame(b'\x00\x52\xff')
-    assert f.get_value(1) == -1
-    f = SmlFrame(b'\x01\xff\x33\x62\x1e')
-    assert f.get_value(3) == 30
-    f = SmlFrame(b'\xab\xcd\x87\x44\x65\x0c\x6a\x50\xb5')
-    assert f.get_value(4) == 208294069
-
-    # now with stuff appended
-    f = SmlFrame(b'\x56\x00\x04\xeb\x09\x6c\x12\x34')
-    assert f.get_value(0) == 82512236
-    f = SmlFrame(b'\xaa\xbb\x52\xff\xcc\xdd')
-    assert f.get_value(2) == -1
-    f = SmlFrame(b'\x52\x62\x1e\x99')
-    assert f.get_value(1) == 30
-    f = SmlFrame(b'\x65\x0c\x6a\x50\xb5\x77\x88')
-    assert f.get_value(0) == 208294069
-
-
-def test_get_next_pos():
-    f = SmlFrame(b'\x52\xff')
-    assert f.get_value(0) == -1
-    assert f.next_pos == 2
-
-    f = SmlFrame(b'\x71\xff')
-    f.next_pos = 9999
-    assert f.get_value(0) == [None]
-    assert f.next_pos == 1
-
-
-def test_none():
-    f = SmlFrame(b'\x01\x01\x01\xff')
-    assert f.get_value() is None
-    assert f.next_pos == 1
-
-    f.next_pos = 9999
-    assert f.get_value(1) is None
-    assert f.next_pos == 2
-
-    assert f.get_value() is None
-    assert f.next_pos == 3
-
-
-def test_get_list():
-    f = SmlFrame(b'\x72\x52\xff\x62\x1e')
-
-    r = f.get_value(0)
-    assert f.next_pos == 1
-    assert r == [None, None]
-
-    f.next_pos = 9999
-    assert f.get_value(1) == -1
-    assert f.next_pos == 3
-
-    assert f.get_value() == 30
-    assert f.next_pos == 5
-
-    f = SmlFrame(a2b_hex(
-        '77070100010800ff'
-        '6500000782'
-        '01'
-        '621e'
-        '52ff'
-        '59000000000dd359d6'
-        '01'
-        'ff'))
-    r = f.get_value(0)
-    assert f.next_pos == 1
-    assert r == [None, None, None, None, None, None, None]
-
-    assert f.get_value() == '0100010800ff'
-    assert f.get_value() == 1922
-    assert f.get_value() is None
-    assert f.get_value() == 30
-    assert f.get_value() == -1
-
-    assert f.get_value() == 231954902
-    assert f.get_value() is None
-
-    v_list = f.get_value(0)
-    for i, _ in enumerate(v_list):
-        v_list[i] = f.get_value()
-    assert v_list == ['0100010800ff', 1922, None, 30, -1, 231954902, None]
-
-
-def test_str():
-    f = SmlFrame(b'\x07\x01\x00\x01\x08\x00\xFF')
-    f.next_pos = 9999
-    assert f.get_value(0) == '0100010800ff'
-    assert f.next_pos == 7
-
-
-def test_bool():
-    f = SmlFrame(b'\x42\x01')
-    f.next_pos = 9999
-    assert f.get_value(0) is True
-    assert f.next_pos == 2
-
-    f = SmlFrame(b'\x42\x00')
-    assert f.get_value(0) is False
-
-
-def test_long_str():
-    f = SmlFrame(a2b_hex('8302010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102FF'))  # noqa: E501
-    assert f.get_value(0) == '010203040101010101010101010101010101010101010101010101010101010101010101010101010101010101010102'    # noqa: E501
-    assert f.next_pos == 50
-    assert f.buffer[50] == 0xFF