tests/test-check-code.t

run-tests: collect aggregate code coverage

Before this patch, every Python process during a code coverage run was
writing coverage data to the same file. I'm not sure if the coverage
package even tries to obtain a lock on the file. But what I do know is
there was some last write wins leading to loss of code coverage data, at
least with -j > 1.

This patch changes the code coverage mechanism to be multiple process
safe. The mechanism for initializing code coverage via sitecustomize.py
has been tweaked so each Python process will produce a separate coverage
data file on disk. Unless two processes generate the same random value,
there are no race conditions writing to the same file. At the end of the
test run, we combine all written files into an aggregate report.

On my machine, running the full test suite produces a little over
20,000 coverage files consuming ~350 MB. As you can imagine, it takes
several seconds to load and merge these coverage files. But when it is
done, you have an accurate picture of the aggregate code coverage for the
entire test suite, which is ~60% line coverage.

  $ cat > correct.py <<EOF
  > def toto(arg1, arg2):
  >     del arg2
  >     return (5 + 6, 9)
  > EOF
  $ cat > wrong.py <<EOF
  > def toto( arg1, arg2):
  >     del(arg2)
  >     return ( 5+6, 9)
  > EOF
  $ cat > quote.py <<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"
  > EOF
  $ cat > non-py24.py <<EOF
  > # Using builtins that does not exist in Python 2.4
  > if any():
  >     x = all()
  >     y = format(x)
  >     # next(generator) is new in 2.6
  >     z = next(x)
  >     # but generator.next() is okay
  >     x.next()
  >     # and we can make our own next
  >     def next(stuff):
  >         pass
  > 
  > # Do not complain about our own definition
  > def any(x):
  >     pass
  > 
  > # try/except/finally block does not exist in Python 2.4
  >     try:
  >         pass
  >     except StandardError, inst:
  >         pass
  >     finally:
  >         pass
  > 
  > # nested try/finally+try/except is allowed
  >     try:
  >         try:
  >             pass
  >         except StandardError, inst:
  >             pass
  >     finally:
  >         pass
  > 
  > # yield inside a try/finally block is not allowed in Python 2.4
  >     try:
  >         pass
  >         yield 1
  >     finally:
  >         pass
  >     try:
  >         yield
  >         pass
  >     finally:
  >         pass
  > 
  > EOF
  $ cat > classstyle.py <<EOF
  > class newstyle_class(object):
  >     pass
  > 
  > class oldstyle_class:
  >     pass
  > 
  > class empty():
  >     pass
  > 
  > no_class = 1:
  >     pass
  > EOF
  $ check_code="$TESTDIR"/../contrib/check-code.py
  $ "$check_code" ./wrong.py ./correct.py ./quote.py ./non-py24.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
  ./quote.py:5:
   > '"""', 42+1, """and
   missing whitespace in expression
  ./non-py24.py:2:
   > if any():
   any/all/format not available in Python 2.4
  ./non-py24.py:3:
   >     x = all()
   any/all/format not available in Python 2.4
  ./non-py24.py:4:
   >     y = format(x)
   any/all/format not available in Python 2.4
  ./non-py24.py:6:
   >     z = next(x)
   no next(foo) in Python 2.4 and 2.5, use foo.next() instead
  ./non-py24.py:18:
   >     try:
   no try/except/finally in Python 2.4
  ./non-py24.py:35:
   >     try:
   no yield inside try/finally in Python 2.4
  ./non-py24.py:40:
   >     try:
   no yield inside try/finally in Python 2.4
  ./classstyle.py:4:
   > class oldstyle_class:
   old-style class, use class foo(object)
  ./classstyle.py:7:
   > class empty():
   class foo() not available in Python 2.4, use class foo(object)
  [1]
  $ cat > python3-compat.py << EOF
  > foo <> bar
  > reduce(lambda a, b: a + b, [1, 2, 3, 4])
  > dict(key=value)
  > 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 > is-op.py <<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
  > 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 <<EOF
  > except:
  > EOF
  $ "$check_code" for-nolineno.py --nolineno
  for-nolineno.py:0:
   > except:
   naked except clause
  [1]

  $ cat > warning.t <<EOF
  >   $ function warnonly {
  >   > }
  >   $ diff -N aaa
  >   $ function onwarn {}
  > 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 > raise-format.py <<EOF
  > raise SomeException, message
  > # this next line is okay
  > raise SomeException(arg1, arg2)
  > 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 > rst.py <<EOF
  > """problematic rst text
  > 
  > .. note::
  >     wrong
  > """
  > 
  > '''
  > 
  > .. note::
  > 
  >     valid
  > 
  > new text
  > 
  >     .. note::
  > 
  >         also valid
  > '''
  > 
  > """mixed
  > 
  > .. note::
  > 
  >   good
  > 
  >     .. note::
  >         plus bad
  > """
  > 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 <<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)
  > 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 <<EOF
  > {desc}
  > {desc|escape}
  > {desc|firstline}
  > {desc|websub}
  > 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]