Support reading options from a config file, default mypy.ini. #2148
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Also support reading command line flags using `mypy @flagsfile`. Addresses #1249 (but does not completely fix it). The mypy.ini file has the format: ``` [mypy] silent_imports = True python_version = 2.7 ``` Errors in this config file are non-fatal. Comments and blank lines are supported. The `@flagsfile` option reads additional argparse-style flags, including filenames, from `flagsfile`, one per line. This is typically used for passing in a list of files, but it can also be used for passing flags: ``` --silent-imports --py2 mypy ``` This format does not allow comments or blank lines. Each option must appear on a line by itself. Errors are fatal. The mypy.ini file serves as a set of defaults that can be overridden (or in some cases extended) by command line flags. An alternate config file may be specified using a command line flag: `--config-file anywhere.ini`. (There's a trick involved in making this work, read the source. :-)
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Why not add a |
To solve what problem? Where have you seen this pattern before? |
This is to make `strict_optional = True` in mypy.ini work.
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@gvanrossum For the other options mypy has. Putting them directly in the config file is easier than a separate flags file. Even pytest supports this. |
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Well pytest supports everything. :-) I think there are currently three types of flags you cannot put in mypy.ini:
I think the first category definitely doesn't belong in mypy.ini, and the second category also not really. (My use case requires a complex and carefully optimized shell pipeline starting with I'll think of something for the reports category. (UPDATE: See commit below.) |
This fixes the second bullet of #2126 but not the others. It depends on the changes in this branch (in master options.strict_optional does not exist).
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I have one thing I'd like to add to this yet: an explicit list of options that can be per-file, so that if you try to put a global flag in e.g. the |
- Validate per-file options. - Move set of cache-affecting options to options.py. - Use reporter_classes to validate report names.
| return f(a) | ||
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| z.py:1: error: Function is missing a type annotation | ||
| z.py:4: error: call to untyped function "f" in typed context |
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Can you rename the error message to start with a capital c for consistency (though it's unrelated to this PR)?
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| mypy.ini: [mypy]: silent_imports: Not a boolean: nah | ||
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| [case testConfigErrorNotPerFile] |
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What about testing a case where multiple glob rules match the same file?
| options.report_dirs.update(report_dirs) | ||
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| for name, section in parser.items(): | ||
| if name.startswith('mypy-'): |
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Now sections are a little limited. I'd like to be able to specify multiple globs per section to avoid repetition. Here is a potential syntax:
[mypy dir/*.py, dir2/*.py]
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(Not sure if configparser supports this syntax.)
Also, it's unclear if a directory is a valid glob. I think that it should be -- I'd expect [mypy dir] to apply to all files under dir/ if it's a directory.
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Done the first, but without spaces in the syntax -- you have to write `[mypy-dir/.py,dir2/.py].
For the second, that would be more complicated (the fnmatch function doesn't treat slashes special) so for now you have to use dir/*.
| options.per_file_options[glob] = updates | ||
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| def parse_section(prefix: str, template: Options, |
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It could be useful to be able to specify MYPYPATH in the config file, maybe as path = dir.
What about excludes? If we had exclude globs, it would be possible to do simple blacklisting of some files/directories and then just run mypy ..
(No need to implement the above suggestions in this PR even if you think that they would be useful.)
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Agreed on MYPYPATH, I'll do that in a separate PR. Not sure about the blacklisting, that seems useful but potentially complex.
| options.report_dirs.update(report_dirs) | ||
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| for name, section in parser.items(): | ||
| if name.startswith('mypy-'): |
There was a problem hiding this comment.
Done the first, but without spaces in the syntax -- you have to write `[mypy-dir/.py,dir2/.py].
For the second, that would be more complicated (the fnmatch function doesn't treat slashes special) so for now you have to use dir/*.
| options.per_file_options[glob] = updates | ||
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| def parse_section(prefix: str, template: Options, |
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Agreed on MYPYPATH, I'll do that in a separate PR. Not sure about the blacklisting, that seems useful but potentially complex.
| return f(a) | ||
| [out] | ||
| z.py:1: error: Function is missing a type annotation | ||
| z.py:4: error: call to untyped function "f" in typed context |
| [out] | ||
| mypy.ini: [mypy]: silent_imports: Not a boolean: nah | ||
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| [case testConfigErrorNotPerFile] |
Also support reading command line flags using
mypy @flagsfile.Addresses #1249 (but does not completely fix it).
The mypy.ini file has the format:
Errors in this config file are non-fatal. Comments and blank lines
are supported.
The
@flagsfileoption reads additional argparse-style flags,including filenames, from
flagsfile, one per line. This istypically used for passing in a list of files, but it can also be used
for passing flags:
This format does not allow comments or blank lines. Each option must
appear on a line by itself. Errors are fatal.
The mypy.ini file serves as a set of defaults that can be overridden
(or in some cases extended) by command line flags. An alternate
config file may be specified using a command line flag:
--config-file anywhere.ini. (There's a trick involved in makingthis work, read the source. :-)