parttool: added tests to check the external interface (parsing) of the parttool commands

The existing tests detect errors in the internal interface (eg. parttool read-write functions) and did not check for any possible breakages in the args parsing of the parttool commands.

examples/storage/parttool/partitions_example.csv

@@ -3,4 +3,5 @@
 nvs,      data, nvs,     0x9000,  0x6000,
 phy_init, data, phy,     0xf000,  0x1000,
 factory,  app,  factory, 0x10000, 1M,
+custom,   data, nvs,     ,        0x1000,
 storage,  data, spiffs,  ,        0x10000,

examples/storage/parttool/pytest_parttool_example.py

@@ -26,3 +26,22 @@ def test_examples_parttool(dut: Dut) -> None:
     script_path = os.path.join(idf_path, 'examples', 'storage', 'parttool', 'parttool_example.py')
     binary_path = os.path.join(dut.app.binary_path, 'parttool.bin')
     subprocess.check_call([sys.executable, script_path, '--binary', binary_path, '--port', dut.serial.port])
+
+    # following tests check the external interface (parsing) of the parttool commands
+    with open('custom.bin', 'wb') as f:
+        f.write(b'0' * 1024 * 4)
+
+    PARTTOOL = os.path.join(idf_path, 'components', 'partition_table', 'parttool.py')
+    BASE_CMD = [sys.executable, PARTTOOL, '--port', dut.serial.port]
+
+    cmds = ['read_partition --partition-type=data --partition-subtype=nvs --output custom1.bin',
+            'erase_partition --partition-name=custom',
+            'write_partition --partition-name=custom --input custom.bin',
+            'get_partition_info --partition-boot-default --info size']
+
+    for cmd in cmds:
+        subprocess.check_call(BASE_CMD + cmd.split())
+
+    clean_files = ['custom.bin', 'custom1.bin']
+    for clean_file in clean_files:
+        os.unlink(clean_file)