feat: Add the update command

README.md

@@ -139,3 +139,11 @@ The **verify** command takes a binary file and compares it to the contents of th
 eeprom verify binary_file.bin
 $ 005A expected 2A found 3F
 ```
+
+## update
+
+The **update** command updates the contents of the EEPROM where it differs from the contents of a passed binary file. If they are similar this is much faster than writing the entire EEPROM, however it does add an extra read operation so if the contents differ greatly it can take longer.
+
+```bash
+eeprom update binary_file.bin
+```

eeprom/cli.py

@@ -93,9 +93,32 @@ def verify(binary_file):
         exit(1)
 
 
+@click.command()
+@click.argument("binary_file", type=click.File("rb"))
+def update(binary_file):
+    """
+    Update the contents of the EEPROM with the contents of a binary file.
+
+    This will read the EEPROM and overwrite any data that does not match the provided
+    file. This is done in blocks of 16 addresses. When the existing contents are similar
+    to the contents of the file this is much quicker than write command, however when
+    they differ greatly the extra time taken to read the EEPROM should be taken into
+    account.
+    """
+    programmer = Programmer()
+    new_data = list(binary_file.read())
+    existing_data = programmer.read()
+    for address in range(0, len(new_data), 16):
+        new_block = new_data[address : address + 16]
+        existing_block = existing_data[address : address + 16]
+        if new_block != existing_block:
+            programmer.write_block(address, new_block)
+
+
 cli.add_command(version)
 cli.add_command(read_byte)
 cli.add_command(write_byte)
 cli.add_command(write)
 cli.add_command(read)
 cli.add_command(verify)
+cli.add_command(update)

tests/conftest.py

@@ -159,3 +159,10 @@ def _read_serial_responses(data):
         return messages
 
     return _read_serial_responses
+
+
+@pytest.fixture
+def altered_binary_file_contents(binary_file_contents):
+    altered_binary_file_contents = list(binary_file_contents)
+    altered_binary_file_contents[0x0050] = 0xFF
+    return altered_binary_file_contents

tests/test_cli/test_update.py

@@ -0,0 +1,73 @@
+import pytest
+
+from eeprom import cli
+
+
+@pytest.fixture
+def altered_binary_file_contents(binary_file_contents):
+    altered_binary_file_contents = list(binary_file_contents)
+    altered_binary_file_contents[0x0050] = 0xFF
+    return altered_binary_file_contents
+
+
+@pytest.fixture
+def matching_update_result(
+    default_programmer,
+    runner,
+    read_serial_responses,
+    binary_file_path,
+    binary_file_contents,
+):
+    default_programmer.arduino.serial_connection.readline.side_effect = read_serial_responses(
+        binary_file_contents
+    )
+    return runner.invoke(cli, f"update {binary_file_path}")
+
+
+@pytest.fixture
+def non_matching_update_result(
+    default_programmer,
+    runner,
+    read_serial_responses,
+    binary_file_path,
+    altered_binary_file_contents,
+    serial_ack,
+):
+    default_programmer.arduino.serial_connection.readline.side_effect = read_serial_responses(
+        altered_binary_file_contents
+    ) + [
+        serial_ack
+    ]
+    return runner.invoke(cli, f"update {binary_file_path}")
+
+
+def test_matching_exit_code(matching_update_result):
+    assert matching_update_result.exit_code == 0
+
+
+def test_non_matching_exit_code(non_matching_update_result):
+    assert non_matching_update_result.exit_code == 0
+
+
+def test_matching_serial_message_sent(
+    default_programmer,
+    matching_update_result,
+    assert_messages_sent,
+    read_serial_requests,
+    binary_file_contents,
+):
+    assert_messages_sent(default_programmer, read_serial_requests(binary_file_contents))
+
+
+def test_non_matching_serial_message_sent(
+    default_programmer,
+    non_matching_update_result,
+    assert_messages_sent,
+    read_serial_requests,
+    binary_file_contents,
+):
+    block = "".join([f"{_:02X}" for _ in binary_file_contents[0x50 : 0x50 + 16]])
+    write_messages = [f"S0050{block}\n".encode()]
+    assert_messages_sent(
+        default_programmer, read_serial_requests(binary_file_contents) + write_messages
+    )

tests/test_cli/test_verify.py

@@ -3,13 +3,6 @@
 from eeprom import cli
 
 
-@pytest.fixture
-def altered_binary_file_contents(binary_file_contents):
-    altered_binary_file_contents = list(binary_file_contents)
-    altered_binary_file_contents[0x0050] = 0xFF
-    return altered_binary_file_contents
-
-
 @pytest.fixture
 def matching_verify_result(
     default_programmer,