Ansible Inventory plugins: the verify_file method of InventoryModule base class receives the input string modified with a path-like prefix - ansible

Question

I have implemented an Inventory plugin according to the guide on developing dynamic inventory.
On invoking my plugin via the CLI, I am experiencing an issue with the way the inventory source is handled from the command line to the verify_file() method. In particular, I am passing a simple string to the command line but the verify_file() method is observed to receive not just that string itself, but actually a concatenation of the string plus my user home path (i.e. the path that is equivalent to "~"). For example, an input of "input_string" from the command line will provide "/home/{user}/input_string" to the verify_file() method.
This behaviour is unexpected since the built-in host_list inventory plugin, like my custom plugin, expects a simple string (not a path) and, also, does seem to omit any logic to handle any expectation of receiving such a path-like input.
Clearly I could make my plugin work by adding some additional logic to handle what is occurring. But I would like to understand if/how I can actually avoid the modification of the input from happening at all - like it seems to be working already for the built-in host_list plugin.
Here is the command I am issuing to the CLI:
ansible-inventory -i 'myUniqueInputString' --list --output ansible-inventory -vvvv
Here is an excerpt of a minimal repro:
class InventoryModule(BaseInventoryPlugin):
NAME = 'my_plugin'
def __init__(self):
super(InventoryModule, self).__init__()
self.foo_stuff = {}
def verify_file(self, input_string):
"""check the input value is same as was passed via the CLI."""
valid = False
b_path = to_bytes(input_string, errors='surrogate_or_strict')
if not os.path.exists(b_path) and ',' not in input_string:
try:
assert input_string == "myUniqueInputString"
valid = True
except AssertionError:
print(f"Received this: {input_string} but was expecting this: myUniqueInputString")
return valid
These is the relevant line from the stdout:
Received this: /home/testuser/myUniqueInputString but was expecting this: myUniqueInputString
The key evidence is the input string of "myUniqueInputString" providing "/home/testuser/myUniqueInputString" to the function. How to stop this modification of the input?