Function check_argument_for_valid_config_file_name

pub(crate) fn check_argument_for_valid_config_file_name(
    user_selected_config_file_name: &str,
) -> Result<String, ConfigFileDefinitionError>

Checks if the provided string is a valid path to a .toml configuration file.

This function validates a user-selected configuration file path by ensuring that:

• The path exists on the file system.
• It points to a regular file (not a directory).
• The file has an extension.
• The file’s extension is .toml.

Arguments

• user_selected_config_file_name - A string slice representing the potential path to the configuration file.

Returns

A Result containing the validated and owned file path as a String on success.

Errors

Returns a ConfigFileDefinitionError if any validation check fails:

• ConfigFileDefinitionError::PathDoesNotExist: If no file or directory exists at the given path.
• ConfigFileDefinitionError::IsNotAFile: If the path points to a directory, not a regular file.
• ConfigFileDefinitionError::FileNameHasNoSuffix: If the path does not have a file extension.
• ConfigFileDefinitionError::SuffixIsNotToml: If the file’s extension is not .toml.