contrib/pylintrc

wireproto: define human output side channel frame

Currently, the SSH protocol delivers output tailored for people over
the stderr file descriptor. The HTTP protocol doesn't have this
file descriptor (because it only has an input and output pipe). So
it encodes textual output intended for humans within the protocol
responses. So response types have a facility for capturing output
to be printed to users. Some don't. And sometimes the implementation
of how that output is conveyed is super hacky.

On top of that, bundle2 has an "output" part that is used to store
output that should be printed when this part is encountered.
bundle2 also has the concept of "interrupt" chunks, which can be
used to signal that the regular bundle2 stream is to be
preempted by an out-of-band part that should be processed immediately.
This "interrupt" part can be an "output" part and can be used to
print data on the receiver.

The status quo is inconsistent and insane. We can do better.

This commit introduces a dedicated frame type on the frame-based
protocol for denoting textual data that should be printed on the
receiver. This frame type effectively constitutes a side-channel
by which textual data can be printed on the receiver without
interfering with other in-progress transmissions, such as the
transmission of command responses.

But wait - there's more! Previous implementations that transferred
textual data basically instructed the client to "print these bytes."
This suffered from a few problems.

First, the text data that was transmitted and eventually printed
originated from a server with a specic i18n configuration. This
meant that clients would see text using whatever the i18n settings
were on the server. Someone in France could connect to a server in
Japan and see unlegible Japanese glyphs - or maybe even mojibake.

Second, the normalization of all text data originated on servers
resulted in the loss of the ability to apply formatting to that
data. Local Mercurial clients can apply specific formatting
settings to individual atoms of text. For example, a revision can
be colored differently from a commit message. With data over the
wire, the potential for this rich formatting was lost. The best you
could do (without parsing the text to be printed), was apply a
universal label to it and e.g. color it specially.

The new mechanism for instructing the peer to print data does
not have these limitations.

Frames instructing the peer to print text are composed of a
formatting string plus arguments. In other words, receivers can
plug the formatting string into the i18n database to see if a local
translation is available. In addition, each atom being instructed
to print has a series of "labels" associated with it. These labels
can be mapped to the Mercurial UI's labels so locally configured
coloring, styling, etc settings can be applied.

What this all means is that textual messages originating on servers
can be localized on the client and richly formatted, all while
respecting the client's settings. This is slightly more complicated
than "print these bytes." But it is vastly more user friendly.

FWIW, I'm not aware of other protocols that attempt to encode
i18n and textual styling in this manner. You could lobby the
claim that this feature is over-engineered. However, if I were to
sit in the shoes of a non-English speaker learning how to use
version control, I think I would *love* this feature because
it would enable me to see richly formatted text in my chosen
locale.

Anyway, we only implement support for encoding frames of this
type and basic tests for that encoding. We'll still need to
hook up the server and its ui instance to emit these frames.
I recognize this feature may be a bit more controversial than
other aspects of the wire protocol because it is a bit
"radical." So I'd figured I'd start small to test the waters and
see if others feel this feature is worthwhile.

Differential Revision: https://phab.mercurial-scm.org/D2872

# lint Python modules using external checkers.
#
# This is the main checker controlling the other ones and the reports
# generation. It is itself both a raw checker and an astng checker in order
# to:
# * handle message activation / deactivation at the module level
# * handle some basic but necessary stats'data (number of classes, methods...)
#
[MASTER]

# Specify a configuration file.
#rcfile=

# Python code to execute, usually for sys.path manipulation such as
# pygtk.require().
#init-hook=

# Profiled execution.
profile=no

# Add <file or directory> to the black list. It should be a base name, not a
# path. You may set this option multiple times.
ignore=CVS

# Pickle collected data for later comparisons.
persistent=yes

# Set the cache size for astng objects.
cache-size=500

# List of plugins (as comma separated values of python modules names) to load,
# usually to register additional checkers.
load-plugins=


[MESSAGES CONTROL]

# Enable only checker(s) with the given id(s). This option conflicts with the
# disable-checker option
#enable-checker=

# Enable all checker(s) except those with the given id(s). This option
# conflicts with the enable-checker option
#disable-checker=

# Enable all messages in the listed categories (IRCWEF).
#enable-msg-cat=

# Disable all messages in the listed categories (IRCWEF).
disable-msg-cat=I

# Enable the message(s) with the given id(s).
#enable-msg=

# Disable the message(s) with the given id(s).
# W0704: except: pass
# C0111: missing docstring
# W0403: for the time being absolute imports don't play nice with demandimport
disable-msg=W0704,C0111,W0403


[REPORTS]

# Set the output format. Available formats are text, parseable, colorized, msvs
# (visual studio) and html
output-format=text

# Include message's id in output
include-ids=yes

# Put messages in a separate file for each module / package specified on the
# command line instead of printing them on stdout. Reports (if any) will be
# written in a file name "pylint_global.[txt|html]".
files-output=no

# Tells whether to display a full report or only the messages
reports=yes

# Python expression which should return a note less than 10 (10 is the highest
# note). You have access to the variables errors warning, statement which
# respectively contain the number of errors / warnings messages and the total
# number of statements analyzed. This is used by the global evaluation report
# (R0004).
evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)

# Add a comment according to your evaluation note. This is used by the global
# evaluation report (R0004).
comment=no

# Enable the report(s) with the given id(s).
#enable-report=

# Disable the report(s) with the given id(s).
#disable-report=


# try to find bugs in the code using type inference
#
[TYPECHECK]

# Tells whether missing members accessed in mixin class should be ignored. A
# mixin class is detected if its name ends with "mixin" (case insensitive).
ignore-mixin-members=yes

# List of classes names for which member attributes should not be checked
# (useful for classes with attributes dynamically set).
ignored-classes=SQLObject

# When zope mode is activated, add a predefined set of Zope acquired attributes
# to generated-members.
zope=no

# List of members which are set dynamically and missed by pylint inference
# system, and so shouldn't trigger E0201 when accessed.
generated-members=REQUEST,acl_users,aq_parent


# checks for
# * unused variables / imports
# * undefined variables
# * redefinition of variable from builtins or from an outer scope
# * use of variable before assignment
#
[VARIABLES]

# Tells whether we should check for unused import in __init__ files.
init-import=yes

# A regular expression matching names used for dummy variables (i.e. not used).
dummy-variables-rgx=dummy

# List of additional names supposed to be defined in builtins. Remember that
# you should avoid to define new builtins when possible.
additional-builtins=


# checks for :
# * doc strings
# * modules / classes / functions / methods / arguments / variables name
# * number of arguments, local variables, branches, returns and statements in
# functions, methods
# * required module attributes
# * dangerous default values as arguments
# * redefinition of function / method / class
# * uses of the global statement
#
[BASIC]

# Required attributes for module, separated by a comma
required-attributes=

# Regular expression which should only match functions or classes name which do
# not require a docstring
no-docstring-rgx=__.*__

# Regular expression which should only match correct module names
module-rgx=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$

# Regular expression which should only match correct module level names
const-rgx=(([a-zA-Z_][a-zA-Z0-9_]*)|(__.*__))$

# Regular expression which should only match correct class names
class-rgx=[a-zA-Z_][a-zA-Z0-9]+$

# Regular expression which should only match correct function names
function-rgx=[a-z_][a-z0-9_]{2,30}$

# Regular expression which should only match correct method names
method-rgx=[a-z_][a-z0-9_]{2,30}$

# Regular expression which should only match correct instance attribute names
attr-rgx=[a-z_][a-z0-9_]{1,30}$

# Regular expression which should only match correct argument names
argument-rgx=[a-z_][a-z0-9_]{0,30}$

# Regular expression which should only match correct variable names
variable-rgx=[a-z_][a-z0-9_]{0,30}$

# Regular expression which should only match correct list comprehension /
# generator expression variable names
inlinevar-rgx=[A-Za-z_][A-Za-z0-9_]*$

# Good variable names which should always be accepted, separated by a comma
good-names=i,j,k,ex,Run,_,ui,c,fn,f,fd,l

# Bad variable names which should always be refused, separated by a comma
bad-names=foo,bar,baz,toto,tutu,tata

# List of builtins function names that should not be used, separated by a comma
#bad-functions=map,filter,apply,input
bad-functions=map,filter,apply,input


# checks for
# * external modules dependencies
# * relative / wildcard imports
# * cyclic imports
# * uses of deprecated modules
#
[IMPORTS]

# Deprecated modules which should not be used, separated by a comma
deprecated-modules=regsub,TERMIOS,Bastion,rexec

# Create a graph of every (i.e. internal and external) dependencies in the
# given file (report R0402 must not be disabled)
import-graph=

# Create a graph of external dependencies in the given file (report R0402 must
# not be disabled)
ext-import-graph=

# Create a graph of internal dependencies in the given file (report R0402 must
# not be disabled)
int-import-graph=


# checks for sign of poor/misdesign:
# * number of methods, attributes, local variables...
# * size, complexity of functions, methods
#
[DESIGN]

# Maximum number of arguments for function / method
max-args=5

# Maximum number of locals for function / method body
max-locals=15

# Maximum number of return / yield for function / method body
max-returns=6

# Maximum number of branch for function / method body
max-branchs=12

# Maximum number of statements in function / method body
max-statements=50

# Maximum number of parents for a class (see R0901).
max-parents=7

# Maximum number of attributes for a class (see R0902).
max-attributes=7

# Minimum number of public methods for a class (see R0903).
min-public-methods=2

# Maximum number of public methods for a class (see R0904).
max-public-methods=20


# checks for :
# * methods without self as first argument
# * overridden methods signature
# * access only to existent members via self
# * attributes not defined in the __init__ method
# * supported interfaces implementation
# * unreachable code
#
[CLASSES]

# List of interface methods to ignore, separated by a comma. This is used for
# instance to not check methods defines in Zope's Interface base class.
ignore-iface-methods=isImplementedBy,deferred,extends,names,namesAndDescriptions,queryDescriptionFor,getBases,getDescriptionFor,getDoc,getName,getTaggedValue,getTaggedValueTags,isEqualOrExtendedBy,setTaggedValue,isImplementedByInstancesOf,adaptWith,is_implemented_by

# List of method names used to declare (i.e. assign) instance attributes.
defining-attr-methods=__init__,__new__,setUp


# checks for :
# * unauthorized constructions
# * strict indentation
# * line length
# * use of <> instead of !=
#
[FORMAT]

# Maximum number of characters on a single line.
max-line-length=80

# Maximum number of lines in a module
max-module-lines=1000

# String used as indentation unit. This is usually " " (4 spaces) or "\t" (1
# tab).
indent-string='    '


# checks for:
# * warning notes in the code like FIXME, XXX
# * PEP 263: source code with non ascii character but no encoding declaration
#
[MISCELLANEOUS]

# List of note tags to take in consideration, separated by a comma.
notes=FIXME,XXX,TODO


# checks for similarities and duplicated code. This computation may be
# memory / CPU intensive, so you should disable it if you experiments some
# problems.
#
[SIMILARITIES]

# Minimum lines number of a similarity.
min-similarity-lines=4

# Ignore comments when computing similarities.
ignore-comments=yes

# Ignore docstrings when computing similarities.
ignore-docstrings=yes