error when add type hint in class without value

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#795 4 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
javascript, python
Domain
compilers

Research direction

Start by reproducing the class example with the reported Python and Transcrypt versions, then inspect compiler.py at line 2028 where the traceback occurs. Confirm that translating the annotation-only class no longer raises the NoneType error and that the generated JavaScript reflects the intended handling of the uninitialized attribute.

Written by the indexing model from the issue text.

Description

this project is awesome! but i have some problem when use it.

Env

  • python 3.9.5 & 3.8.10
  • transcrypt 3.9.0

code

python


class a:
    b: str

js


export var a =  __class__ ('a', [object], {
	__module__: __name__,
	b: 
});

error output

Transcrypt (TM) Python to JavaScript Small Sane Subset Transpiler Version 3.9.0
Copyright (C) Geatec Engineering. License: Apache 2.0


Saving target code in: /home/kaiyo/vscode/addon.py/__target__/org.transcrypt.__runtime__.js
Traceback (most recent call last):
  File "/home/kaiyo/.local/lib/python3.9/site-packages/transcrypt/modules/org/transcrypt/compiler.py", line 2028, in visit_ClassDef
    self.visit (statement.value)
  File "/home/kaiyo/.local/lib/python3.9/site-packages/transcrypt/modules/org/transcrypt/compiler.py", line 985, in visit
    super () .visit (node)
  File "/usr/lib/python3.9/ast.py", line 407, in visit
    return visitor(node)
  File "/usr/lib/python3.9/ast.py", line 411, in generic_visit
    for field, value in iter_fields(node):
  File "/usr/lib/python3.9/ast.py", line 249, in iter_fields
    for field in node._fields:
AttributeError: 'NoneType' object has no attribute '_fields'

Saving target code in: /home/kaiyo/vscode/addon.py/__target__/test.js

Ready

i have no idea what value b should has. in python print(b) will throw an error, but in js except a is null , use a.b never throw an error

Dominant language
Python
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