Indent when doing line breaks

[qubitron]

Feedback from twitter here: https://twitter.com/amuellerml/status/1060895092230291457

Actual behavior

a = 1 + \
<--- indent is here

Expected behavior

a = 1 + \
    <--- indent is here

[cbrnr]

#481 is certainly related because it also concerns proper PEP8-style indentation.

[DonJayamanne]

This issue was moved to microsoft/python-language-server#385

[jakebailey]

I'm pretty sure this isn't a language server problem. The extension tells the editor what to do on enter here:

https://github.com/Microsoft/vscode-python/blob/d0c239fcc78fee9a05713ced15b08e6806affc24/src/client/extension.ts#L121-L140

This is distinct from textDocument/onTypeFormatting.

[jakebailey]

Adding this seems to work (handling comments and ignoring all-whitespace prefixes):

{
    beforeText: /^(?!\s+\\)[^#\n]+\\\s*/,
    action: { indentAction: IndentAction.Indent }
},

Tests: https://regex101.com/r/kfNBtR/1

[jakebailey]

Though, commented out line continuations are syntax errors, so that regex is probably overkill:

  File ".\continuation.py", line 2
    a = 1+  # \
              ^
SyntaxError: invalid syntax

[kevindavenport]

Would expecting indents after breaking a line of inputs be in the same issue?

subprocess.run(termqry,
shell=True, 
heck=True)

vs

subprocess.run(termqry,
               shell=True,
               check=True)

or is this a simple preference setting?

[cbrnr]

The latter is strongly preferred in the Python community since it is standardized in PEP8. This is also much more important than indentation after a backslash (as in the top example), which almost never happens in Python code. Adding to your example, this would also be the expected behavior:

x = [1, 2, 3,
     4, 5, 6]

and not

x = [1, 2, 3,
4, 5, 6]

So basically it's about how to indent after breaking inside of all kinds of brackets.

[kevindavenport]

Thank you Clemens, that is helpful. You are right about the brackets, I hope the change goes through.
Do you know how to get the right indenting in what I described via config changes?

[cbrnr]

Currently this is not possible. You can manually indent the second line, which will then correctly indent all subsequent lines. But this is very cumbersome, hence this issue.

[DonJayamanne]

Will be addressed as part of #481

[jakebailey]

Reopening to PR in my line continuation rule.

[ericsnowcurrently]

Prescribed Solution:

• Modify src/client/extension.ts
• Modify the beforeText setting to use the below regex:
• Add tests

There may be a more correct regex to use:

/^(?!\s+\\)[^#\n]+\\$/

See #5821 (comment).

[karrtikr]

Closing as fix for #4241 will cover it.