tests/pdiff

interfaces: convert the zope `Attribute` attrs to regular fields

At this point, we should have a useful protocol class.

The file syntax requires the type to be supplied for any fields that are
declared, but we'll leave the complex ones partially unspecified for now, for
simplicity.  (Also, the things documented as `Callable` are really as future
type annotating worked showed- roll with it for now, but they're marked as TODO
for fixing later.)  All of the fields and all of the attrs will need type
annotations, or the type rules say they are considered to be `Any`.  That can be
done in a separate pass, possibly applying the `dirstate.pyi` file generated
from the concrete class.

The first cut of this turned the `interfaceutil.Attribute` fields into plain
fields, and thus the types on them.  PyCharm flagged a few things as having
incompatible signatures when the concrete dirstate class subclassed this, when
the concrete class has them declared as `@property`.  So they've been changed to
`@property` here in those cases.  The remaining fields that are decorated in the
concrete class have comments noting the differences.  We'll see if they need to
be changed going forward, but leave them for now.  We'll be in trouble if the
`@util.propertycache` is needed, because we can't import that module here at
runtime, due to circular imports.

#!/bin/sh

# Script to get stable diff output on any platform.
#
# Output of this script is almost equivalent to GNU diff with "-Nru".
#
# Use this script as "hg pdiff" via extdiff extension with preparation
# below in test scripts:
#
#   $ cat >> $HGRCPATH <<EOF
#   > [extdiff]
#   > pdiff = sh "$RUNTESTDIR/pdiff"
#   > EOF

filediff(){
    # USAGE: filediff file1 file2 [header]

    # compare with /dev/null if file doesn't exist (as "-N" option)
    file1="$1"
    if test ! -f "$file1"; then
        file1=/dev/null
    fi
    file2="$2"
    if test ! -f "$file2"; then
        file2=/dev/null
    fi

    if cmp -s "$file1" "$file2" 2> /dev/null; then
        # Return immediately, because comparison isn't needed. This
        # also avoids redundant message of diff like "No differences
        # encountered" (on Solaris)
        return
    fi

    if test -n "$3"; then
        # show header only in recursive case
        echo "$3"
    fi

    # replace "/dev/null" by corresponded filename (as "-N" option)
    diff -u "$file1" "$file2" |
    sed "s@^--- /dev/null\(.*\)\$@--- $1\1@" |
    sed "s@^\+\+\+ /dev/null\(.*\)\$@+++ $2\1@"

    # in this case, files differ from each other
    return 1
}

if test -d "$1" -o -d "$2"; then
    # ensure comparison in dictionary order
    (
    if test -d "$1"; then (cd "$1" && find . -type f); fi
    if test -d "$2"; then (cd "$2" && find . -type f); fi
    ) |
    sed 's@^\./@@g' | sort | uniq |
    while read file; do
        filediff "$1/$file" "$2/$file" "diff -Nru $1/$file $2/$file"
    done

    # TODO: there is no portable way for current while-read based
    # implementation to return 1 at detecting changes.
    #
    # On bash and dash, assignment to variable inside while-block
    # doesn't affect outside, because inside while-block is executed
    # in sub-shell. BTW, it affects outside while-block on ksh (as sh
    # on Solaris).
else
    filediff "$1" "$2"
fi