Diff filebeat module fileset test failure

diff-filebeat-fileset-test-failure.py

# Helper to find what's wrong when a Filebeat's fileset
# fails with the error:
#
# The following expected object was not found:
# {
#   [...]
# }
# Searched in:
# [
#   [...]
# ]
#
# Usage:
#    python fileset_error_event_compare.py <file>
#
# Where file contains the whole error above.

import json
import sys

def expect(f, expected, name):
    line = f.readline().strip()
    if line != expected:
        print '{} not found'.format(name)
        print 'Expected: ', expected
        print 'Got:', line
        sys.exit(1)

def readjson(f, start, end, name):
    js = f.readline().strip()
    if js != start:
        print 'Start of {} is not {}, but {}'.format(name, start, js)
        sys.exit(1)

    line = f.readline().strip()
    while line != end:
        js += line
        line = f.readline().rstrip()
    js += line.lstrip()
    try:
        return json.loads(js)
    except:
        print 'Error parsing:', js
        raise

def flatten(d):
    out = dict()
    for k,v in d.iteritems():
        if isinstance(v, dict):
            out.update(dict((k + '.' + xk, xv) for xk,xv in flatten(v).iteritems()))
        else:
            out[k] = v
    return out

def print_doc(name, d):
    print
    print name
    w = max(map(len, d.keys()))
    keys = d.keys()
    keys.sort()
    for k in keys:
        pad = ' '*(w-len(k))
        print k,pad,'=',repr(d[k])

def diff(expected, actual, display=False):
    ek = set(expected.keys())
    ak = set(actual.keys())
    missing = ek - ak
    added = ak - ek
    changed = filter(lambda k: expected[k] != actual[k], ek & ak)
    if display:
        print
        print 'Diff {} added {} missing {} changed:'.format(len(added), len(missing), len(changed))

        for k in missing:
            print '-',k
        for k in added:
            print '+',k
        for k in changed:
            print '|',k
            print '<',repr(expected[k])
            print '>',repr(actual[k])
    return len(ek) + len(ak) -len(added) - len(missing) - 2*len(changed)

f = open(sys.argv[1], 'rb')
expect(f, 'The following expected object was not found:', 'First line')
expected = flatten(readjson(f, '{', '}', 'expected document'))
expect(f, 'Searched in:', 'Separator line')
got = map(flatten, readjson(f, '[', ']', 'Actual documents'))

print_doc('Expected:', expected)

scores = sorted( [ (idx, doc, diff(expected, doc)) for (idx, doc) in enumerate(got) ], key=lambda x: -x[2])
for (idx, doc, score) in scores:
    print_doc('Document #{} score {}:'.format(idx, score), doc)
    diff(expected, doc, display=True)