Fix 'get_code' method if issue is generated from dict

[e0ne]

If issue is generated from dict 'get_code' method doesn't return
code source. This patch fixes this by returning self.code property.

[lukehinds]

Is there a related issue to this to help us get some insight into what this fixes or how to test the change?

[e0ne]

@lukehinds It was an issue with serialization-deserialization of bandit issues. We do some automation on top of bandit and to_dict/from_dict are regular operations. I can provide an example of how to reproduce the issue if needed.

[lukehinds]

yes please @e0ne

[e0ne]

here is a code to reproduce the bug:

from bandit import core

d = {'filename': 'horizon/forms/fields.py',
 'test_name': 'django_mark_safe',
 'test_id': 'B703',
 'issue_severity': 'MEDIUM',
 'issue_confidence': 'HIGH',
 'issue_text': 'Potential XSS on mark_safe function.',
 'line_number': 236,
 'line_range': [236],
 'code': "235         output.append('</select>')\n236         return mark_safe('\\n'.join(output))\n237 \n"}

i = core.issue_from_dict(d)
print(i.code)
print(i.as_dict())

Output:

235         output.append('</select>')
236         return mark_safe('\n'.join(output))
237

{'filename': 'horizon/forms/fields.py', 'test_name': 'django_mark_safe', 'test_id': 'B703', 'issue_severity': 'MEDIUM', 'issue_confidence': 'HIGH', 'issue_text': 'Potential XSS on mark_safe function.', 'line_number': 236, 'line_range': [236], 'code': ''}

As I understood, it's reproducible only when linecache can't load the file.

[e0ne]

@lukehinds as you can see, as_dict method dumps the issue without code

[ericwb]

Please add a unit test

[ericwb]

The get_code() and issue_from_dict() functions are really there for internal calls of Bandit itself and not designed to be external interfaces to use more generally. We do have some interfaces for 3rd parties to create formatters and plugins, but the example given would not be a generally be necessary I would think.