Merge pull request #53 from aureocarneiro/append_command

add Append command

pandablocks/commands.py

@@ -45,6 +45,7 @@
     "GetLine",
     "GetMultiline",
     "Put",
+    "Append",
     "Arm",
     "Disarm",
     "GetBlockInfo",
@@ -293,6 +294,29 @@ def execute(self) -> ExchangeGenerator[None]:
         assert ex.line == "OK"
 
 
+@dataclass
+class Append(Command[None]):
+    """Append the value of a table field.
+
+    Args:
+        field: The field, attribute, or star command to append
+        value: The value, list of strings, to append
+
+    For example::
+
+        Append("SEQ1.TABLE", ["1048576", "0", "1000", "1000"])
+    """
+
+    field: str
+    value: List[str]
+
+    def execute(self) -> ExchangeGenerator[None]:
+        # Multiline table with blank line to terminate
+        ex = Exchange([f"{self.field}<<"] + self.value + [""])
+        yield ex
+        assert ex.line == "OK"
+
+
 class Arm(Command[None]):
     """Arm PCAP for an acquisition by sending ``*PCAP.ARM=``"""
 

tests/test_pandablocks.py

@@ -3,6 +3,7 @@
 import pytest
 
 from pandablocks.commands import (
+    Append,
     ChangeGroup,
     CommandException,
     Get,
@@ -188,6 +189,21 @@ def test_connect_put_no_value():
     assert get_responses(conn, b"OK\n") == [(cmd, None)]
 
 
+def test_connect_append():
+    conn = ControlConnection()
+    cmd = Append("SEQ1.TABLE", ["1048576", "0", "1000", "1000"])
+    assert conn.send(cmd) == b"SEQ1.TABLE<<\n1048576\n0\n1000\n1000\n\n"
+    assert get_responses(conn, b"OK\n") == [(cmd, None)]
+
+
+def test_connect_append_multi_bad_list_format():
+    """Confirm that an invalid data format raises the expected exception"""
+    conn = ControlConnection()
+    cmd = Append("SEQ1.TABLE", [1, 2, 3])
+    with pytest.raises(TypeError):
+        assert conn.send(cmd) == b""
+
+
 def test_get_block_info():
     conn = ControlConnection()
     cmd = GetBlockInfo()