procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
$ cat > correct.py <<NO_CHECK_EOF
> def toto(arg1, arg2):
> del arg2
> return (5 + 6, 9)
> NO_CHECK_EOF
$ cat > wrong.py <<NO_CHECK_EOF
> def toto( arg1, arg2):
> del(arg2)
> return ( 5+6, 9)
> def badwrap():
> return 1 + \\
> 2
> NO_CHECK_EOF
$ cat > quote.py <<NO_CHECK_EOF
> # let's use quote in comments
> (''' ( 4x5 )
> but """\\''' and finally''',
> """let's fool checkpatch""", '1+2',
> '"""', 42+1, """and
> ( 4-1 ) """, "( 1+1 )\" and ")
> a, '\\\\\\\\', "\\\\\\" x-2", "c-1"
> NO_CHECK_EOF
$ cat > classstyle.py <<NO_CHECK_EOF
> class newstyle_class(object):
> pass
>
> class oldstyle_class:
> pass
>
> class empty():
> pass
>
> no_class = 1:
> pass
> NO_CHECK_EOF
$ check_code="$TESTDIR"/../contrib/check-code.py
$ "$check_code" ./wrong.py ./correct.py ./quote.py ./classstyle.py
./wrong.py:1:
> def toto( arg1, arg2):
gratuitous whitespace in () or []
./wrong.py:2:
> del(arg2)
Python keyword is not a function
./wrong.py:3:
> return ( 5+6, 9)
gratuitous whitespace in () or []
missing whitespace in expression
./wrong.py:5:
> return 1 + \
Use () to wrap long lines in Python, not \
./quote.py:5:
> '"""', 42+1, """and
missing whitespace in expression
[1]
$ cat > python3-compat.py << NO_CHECK_EOF
> foo <> bar
> reduce(lambda a, b: a + b, [1, 2, 3, 4])
> dict(key=value)
> NO_CHECK_EOF
$ "$check_code" python3-compat.py
python3-compat.py:1:
> foo <> bar
<> operator is not available in Python 3+, use !=
python3-compat.py:2:
> reduce(lambda a, b: a + b, [1, 2, 3, 4])
reduce is not available in Python 3+
python3-compat.py:3:
> dict(key=value)
dict() is different in Py2 and 3 and is slower than {}
[1]
$ cat > foo.c <<NO_CHECK_EOF
> void narf() {
> strcpy(foo, bar);
> // strcpy_s is okay, but this comment is not
> strcpy_s(foo, bar);
> }
> NO_CHECK_EOF
$ "$check_code" ./foo.c
./foo.c:2:
> strcpy(foo, bar);
don't use strcpy, use strlcpy or memcpy
./foo.c:3:
> // strcpy_s is okay, but this comment is not
don't use //-style comments
[1]
$ cat > is-op.py <<NO_CHECK_EOF
> # is-operator comparing number or string literal
> x = None
> y = x is 'foo'
> y = x is "foo"
> y = x is 5346
> y = x is -6
> y = x is not 'foo'
> y = x is not "foo"
> y = x is not 5346
> y = x is not -6
> NO_CHECK_EOF
$ "$check_code" ./is-op.py
./is-op.py:3:
> y = x is 'foo'
object comparison with literal
./is-op.py:4:
> y = x is "foo"
object comparison with literal
./is-op.py:5:
> y = x is 5346
object comparison with literal
./is-op.py:6:
> y = x is -6
object comparison with literal
./is-op.py:7:
> y = x is not 'foo'
object comparison with literal
./is-op.py:8:
> y = x is not "foo"
object comparison with literal
./is-op.py:9:
> y = x is not 5346
object comparison with literal
./is-op.py:10:
> y = x is not -6
object comparison with literal
[1]
$ cat > for-nolineno.py <<NO_CHECK_EOF
> except:
> NO_CHECK_EOF
$ "$check_code" for-nolineno.py --nolineno
for-nolineno.py:0:
> except:
naked except clause
[1]
$ cat > warning.t <<NO_CHECK_EOF
> $ function warnonly {
> > }
> $ diff -N aaa
> $ function onwarn {}
> NO_CHECK_EOF
$ "$check_code" warning.t
$ "$check_code" --warn warning.t
warning.t:1:
> $ function warnonly {
warning: don't use 'function', use old style
warning.t:3:
> $ diff -N aaa
warning: don't use 'diff -N'
warning.t:4:
> $ function onwarn {}
warning: don't use 'function', use old style
[1]
$ cat > error.t <<NO_CHECK_EOF
> $ [ foo == bar ]
> NO_CHECK_EOF
$ "$check_code" error.t
error.t:1:
> $ [ foo == bar ]
[ foo == bar ] is a bashism, use [ foo = bar ] instead
[1]
$ rm error.t
$ cat > raise-format.py <<NO_CHECK_EOF
> raise SomeException, message
> # this next line is okay
> raise SomeException(arg1, arg2)
> NO_CHECK_EOF
$ "$check_code" not-existing.py raise-format.py
Skipping*not-existing.py* (glob)
raise-format.py:1:
> raise SomeException, message
don't use old-style two-argument raise, use Exception(message)
[1]
$ cat <<NO_CHECK_EOF > tab.t
> indent
> > heredoc
> NO_CHECK_EOF
$ "$check_code" tab.t
tab.t:1:
> indent
don't use tabs to indent
[1]
$ rm tab.t
$ cat > rst.py <<NO_CHECK_EOF
> """problematic rst text
>
> .. note::
> wrong
> """
>
> '''
>
> .. note::
>
> valid
>
> new text
>
> .. note::
>
> also valid
> '''
>
> """mixed
>
> .. note::
>
> good
>
> .. note::
> plus bad
> """
> NO_CHECK_EOF
$ $check_code -w rst.py
rst.py:3:
> .. note::
warning: add two newlines after '.. note::'
rst.py:26:
> .. note::
warning: add two newlines after '.. note::'
[1]
$ cat > ./map-inside-gettext.py <<NO_CHECK_EOF
> print(_("map inside gettext %s" % v))
>
> print(_("concatenating " " by " " space %s" % v))
> print(_("concatenating " + " by " + " '+' %s" % v))
>
> print(_("mapping operation in different line %s"
> % v))
>
> print(_(
> "leading spaces inside of '(' %s" % v))
> NO_CHECK_EOF
$ "$check_code" ./map-inside-gettext.py
./map-inside-gettext.py:1:
> print(_("map inside gettext %s" % v))
don't use % inside _()
./map-inside-gettext.py:3:
> print(_("concatenating " " by " " space %s" % v))
don't use % inside _()
./map-inside-gettext.py:4:
> print(_("concatenating " + " by " + " '+' %s" % v))
don't use % inside _()
./map-inside-gettext.py:6:
> print(_("mapping operation in different line %s"
don't use % inside _()
./map-inside-gettext.py:9:
> print(_(
don't use % inside _()
[1]
web templates
$ mkdir -p mercurial/templates
$ cat > mercurial/templates/example.tmpl <<NO_CHECK_EOF
> {desc}
> {desc|escape}
> {desc|firstline}
> {desc|websub}
> NO_CHECK_EOF
$ "$check_code" --warnings mercurial/templates/example.tmpl
mercurial/templates/example.tmpl:2:
> {desc|escape}
warning: follow desc keyword with either firstline or websub
[1]
'string join across lines with no space' detection
$ cat > stringjoin.py <<NO_CHECK_EOF
> foo = (' foo'
> 'bar foo.'
> 'bar foo:'
> 'bar foo@'
> 'bar foo%'
> 'bar foo*'
> 'bar foo+'
> 'bar foo-'
> 'bar')
> NO_CHECK_EOF
'missing _() in ui message' detection
$ cat > uigettext.py <<NO_CHECK_EOF
> ui.status("% 10s %05d % -3.2f %*s %%"
> # this use '\\\\' instead of '\\', because the latter in
> # heredoc on shell becomes just '\'
> '\\\\ \n \t \0'
> """12345
> """
> '''.:*+-=
> ''' "%-6d \n 123456 .:*+-= foobar")
> NO_CHECK_EOF
superfluous pass
$ cat > superfluous_pass.py <<NO_CHECK_EOF
> # correct examples
> if foo:
> pass
> else:
> # comment-only line means still need pass
> pass
> def nothing():
> pass
> class empty(object):
> pass
> if whatever:
> passvalue(value)
> # bad examples
> if foo:
> "foo"
> pass
> else: # trailing comment doesn't fool checker
> wat()
> pass
> def nothing():
> "docstring means no pass"
> pass
> class empty(object):
> """multiline
> docstring also
> means no pass"""
> pass
> NO_CHECK_EOF
(Checking multiple invalid files at once examines whether caching
translation table for repquote() works as expected or not. All files
should break rules depending on result of repquote(), in this case)
$ "$check_code" stringjoin.py uigettext.py superfluous_pass.py
stringjoin.py:1:
> foo = (' foo'
string join across lines with no space
stringjoin.py:2:
> 'bar foo.'
string join across lines with no space
stringjoin.py:3:
> 'bar foo:'
string join across lines with no space
stringjoin.py:4:
> 'bar foo@'
string join across lines with no space
stringjoin.py:5:
> 'bar foo%'
string join across lines with no space
stringjoin.py:6:
> 'bar foo*'
string join across lines with no space
stringjoin.py:7:
> 'bar foo+'
string join across lines with no space
stringjoin.py:8:
> 'bar foo-'
string join across lines with no space
uigettext.py:1:
> ui.status("% 10s %05d % -3.2f %*s %%"
missing _() in ui message (use () to hide false-positives)
superfluous_pass.py:14:
> if foo:
omit superfluous pass
superfluous_pass.py:17:
> else: # trailing comment doesn't fool checker
omit superfluous pass
superfluous_pass.py:20:
> def nothing():
omit superfluous pass
superfluous_pass.py:23:
> class empty(object):
omit superfluous pass
[1]
Check code fragments embedded in test script
$ cat > embedded-code.t <<NO_CHECK_EOF
> code fragment in doctest style
> >>> x = (1,2)
> ...
> ... x = (1,2)
>
> code fragment in heredoc style
> $ python <<EOF
> > x = (1,2)
> > EOF
>
> code fragment in file heredoc style
> $ python > file.py <<EOF
> > x = (1,2)
> > EOF
> NO_CHECK_EOF
$ "$check_code" embedded-code.t
embedded-code.t:2:
> x = (1,2)
missing whitespace after ,
embedded-code.t:4:
> x = (1,2)
missing whitespace after ,
embedded-code.t:8:
> x = (1,2)
missing whitespace after ,
embedded-code.t:13:
> x = (1,2)
missing whitespace after ,
[1]
"max warnings per file" is shared by all embedded code fragments
$ "$check_code" --per-file=3 embedded-code.t
embedded-code.t:2:
> x = (1,2)
missing whitespace after ,
embedded-code.t:4:
> x = (1,2)
missing whitespace after ,
embedded-code.t:8:
> x = (1,2)
missing whitespace after ,
(too many errors, giving up)
[1]