Add an auto-fix or auto-correct feature

Is your feature request related to a problem? Please describe. It’s nice that Bandit flags lines of code that require attention, but it would be even more valuable to suggest fixes for problem lines. Other linters such as ESLint provide a --fix command line option to automatically fix problems it finds.

See https://eslint.org/docs/user-guide/command-line-interface#options

Describe the solution you’d like A start might be that Bandit includes another field in the output data called suggested fix or something. It would include the modified line of code it found to be wrong with the proposed solution.

For example, if the yaml_load plugin found a case of yaml.load(), it would replace with yaml.load(Loader=yaml.SafeLoader).

Each plugin would need to handle fixes it could address.

Describe alternatives you’ve considered n/a

Additional context https://developer.ibm.com/articles/auto-fix-and-format-your-javascript-with-eslint/

[ericwb]

@lukehinds Yeah, I was thinking Bandit would output a new field of the suggested fix. But it could also have a command line option to actually make the changes in the file automatically. Similar to what ESLint offers.

[ericwb]

Here’s a short example using libcst to auto-correct a problem in code, all while preserving the comments.

import libcst as cst

code = '''
from paramiko import client

class foo:
    def test(self):
        if True:
            ssh_client = client.SSHClient()
            # test test test
            ssh_client.set_missing_host_key_policy(client.AutoAddPolicy) # comment test
'''

class PolicyFix(cst.CSTTransformer):
    def leave_Call(self, original_node: cst.Call, updated_node: cst.Call) -> cst.Call:
        if (cst.ensure_type(original_node.func, cst.Attribute)
            and original_node.func.attr.value == "set_missing_host_key_policy"
            and original_node.args[0].value.attr.value == "AutoAddPolicy"
        ):
            return updated_node.with_deep_changes(
                old_node=updated_node.args[0].value,
                attr=cst.Name("RejectPolicy")
            )
        else:
            return original_node


tree = cst.parse_module(code)
new_tree = tree.visit(PolicyFix())
print(new_tree.code)