1 files changed, 238 insertions, 0 deletions
diff --git a/tests/deckard/pydnstest/matchpart.py b/tests/deckard/pydnstest/matchpart.py
new file mode 100644
index 0000000..294e64c
--- /dev/null
+++ b/tests/deckard/pydnstest/matchpart.py
@@ -0,0 +1,238 @@
+"""matchpart is used to compare two DNS messages using a single criterion"""
+
+from typing import (  # noqa
+    Any, Hashable, Sequence, Tuple, Union)
+
+import dns.edns
+import dns.rcode
+import dns.set
+
+MismatchValue = Union[str, Sequence[Any]]
+
+
+class DataMismatch(Exception):
+    def __init__(self, exp_val, got_val):
+        super().__init__()
+        self.exp_val = exp_val
+        self.got_val = got_val
+
+    @staticmethod
+    def format_value(value: MismatchValue) -> str:
+        if isinstance(value, list):
+            return ' '.join([str(val) for val in value])
+        else:
+            return str(value)
+
+    def __str__(self) -> str:
+        return 'expected "{}" got "{}"'.format(
+            self.format_value(self.exp_val),
+            self.format_value(self.got_val))
+
+    def __eq__(self, other):
+        return (isinstance(other, DataMismatch)
+                and self.exp_val == other.exp_val
+                and self.got_val == other.got_val)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    @property
+    def key(self) -> Tuple[Hashable, Hashable]:
+        def make_hashable(value):
+            if isinstance(value, (list, dns.set.Set)):
+                value = (make_hashable(item) for item in value)
+                value = tuple(value)
+            return value
+
+        return (make_hashable(self.exp_val), make_hashable(self.got_val))
+
+    def __hash__(self) -> int:
+        return hash(self.key)
+
+
+def compare_val(exp, got):
+    """Compare arbitraty objects, throw exception if different. """
+    if exp != got:
+        raise DataMismatch(exp, got)
+    return True
+
+
+def compare_rrs(expected, got):
+    """ Compare lists of RR sets, throw exception if different. """
+    for rr in expected:
+        if rr not in got:
+            raise DataMismatch(expected, got)
+    for rr in got:
+        if rr not in expected:
+            raise DataMismatch(expected, got)
+    if len(expected) != len(got):
+        raise DataMismatch(expected, got)
+    return True
+
+
+def compare_rrs_types(exp_val, got_val, skip_rrsigs):
+    """sets of RR types in both sections must match"""
+    def rr_ordering_key(rrset):
+        if rrset.covers:
+            return rrset.covers, 1  # RRSIGs go to the end of RRtype list
+        else:
+            return rrset.rdtype, 0
+
+    def key_to_text(rrtype, rrsig):
+        if not rrsig:
+            return dns.rdatatype.to_text(rrtype)
+        else:
+            return 'RRSIG(%s)' % dns.rdatatype.to_text(rrtype)
+
+    if skip_rrsigs:
+        exp_val = (rrset for rrset in exp_val
+                   if rrset.rdtype != dns.rdatatype.RRSIG)
+        got_val = (rrset for rrset in got_val
+                   if rrset.rdtype != dns.rdatatype.RRSIG)
+
+    exp_types = frozenset(rr_ordering_key(rrset) for rrset in exp_val)
+    got_types = frozenset(rr_ordering_key(rrset) for rrset in got_val)
+    if exp_types != got_types:
+        exp_types = tuple(key_to_text(*i) for i in sorted(exp_types))
+        got_types = tuple(key_to_text(*i) for i in sorted(got_types))
+        raise DataMismatch(exp_types, got_types)
+
+
+def check_question(question):
+    if len(question) > 2:
+        raise NotImplementedError("More than one record in QUESTION SECTION.")
+
+
+def match_opcode(exp, got):
+    return compare_val(exp.opcode(),
+                       got.opcode())
+
+
+def match_qtype(exp, got):
+    check_question(exp.question)
+    check_question(got.question)
+    if not exp.question and not got.question:
+        return True
+    if not exp.question:
+        raise DataMismatch("<empty question>", got.question[0].rdtype)
+    if not got.question:
+        raise DataMismatch(exp.question[0].rdtype, "<empty question>")
+    return compare_val(exp.question[0].rdtype,
+                       got.question[0].rdtype)
+
+
+def match_qname(exp, got):
+    check_question(exp.question)
+    check_question(got.question)
+    if not exp.question and not got.question:
+        return True
+    if not exp.question:
+        raise DataMismatch("<empty question>", got.question[0].name)
+    if not got.question:
+        raise DataMismatch(exp.question[0].name, "<empty question>")
+    return compare_val(exp.question[0].name,
+                       got.question[0].name)
+
+
+def match_qcase(exp, got):
+    check_question(exp.question)
+    check_question(got.question)
+    if not exp.question and not got.question:
+        return True
+    if not exp.question:
+        raise DataMismatch("<empty question>", got.question[0].name.labels)
+    if not got.question:
+        raise DataMismatch(exp.question[0].name.labels, "<empty question>")
+    return compare_val(exp.question[0].name.labels,
+                       got.question[0].name.labels)
+
+
+def match_subdomain(exp, got):
+    if not exp.question:
+        return True
+    if got.question:
+        qname = got.question[0].name
+    else:
+        qname = dns.name.root
+    if exp.question[0].name.is_superdomain(qname):
+        return True
+    raise DataMismatch(exp, got)
+
+
+def match_flags(exp, got):
+    return compare_val(dns.flags.to_text(exp.flags),
+                       dns.flags.to_text(got.flags))
+
+
+def match_rcode(exp, got):
+    return compare_val(dns.rcode.to_text(exp.rcode()),
+                       dns.rcode.to_text(got.rcode()))
+
+
+def match_answer(exp, got):
+    return compare_rrs(exp.answer,
+                       got.answer)
+
+
+def match_answertypes(exp, got):
+    return compare_rrs_types(exp.answer,
+                             got.answer, skip_rrsigs=True)
+
+
+def match_answerrrsigs(exp, got):
+    return compare_rrs_types(exp.answer,
+                             got.answer, skip_rrsigs=False)
+
+
+def match_authority(exp, got):
+    return compare_rrs(exp.authority,
+                       got.authority)
+
+
+def match_additional(exp, got):
+    return compare_rrs(exp.additional,
+                       got.additional)
+
+
+def match_edns(exp, got):
+    if got.edns != exp.edns:
+        raise DataMismatch(exp.edns,
+                           got.edns)
+    if got.payload != exp.payload:
+        raise DataMismatch(exp.payload,
+                           got.payload)
+
+
+def match_nsid(exp, got):
+    nsid_opt = None
+    for opt in exp.options:
+        if opt.otype == dns.edns.NSID:
+            nsid_opt = opt
+            break
+    # Find matching NSID
+    for opt in got.options:
+        if opt.otype == dns.edns.NSID:
+            if not nsid_opt:
+                raise DataMismatch(None, opt.data)
+            if opt == nsid_opt:
+                return True
+            else:
+                raise DataMismatch(nsid_opt.data, opt.data)
+    if nsid_opt:
+        raise DataMismatch(nsid_opt.data, None)
+    return True
+
+
+MATCH = {"opcode": match_opcode, "qtype": match_qtype, "qname": match_qname, "qcase": match_qcase,
+         "subdomain": match_subdomain, "flags": match_flags, "rcode": match_rcode,
+         "answer": match_answer, "answertypes": match_answertypes,
+         "answerrrsigs": match_answerrrsigs, "authority": match_authority,
+         "additional": match_additional, "edns": match_edns,
+         "nsid": match_nsid}
+
+
+def match_part(exp, got, code):
+    try:
+        return MATCH[code](exp, got)
+    except KeyError:
+        raise NotImplementedError('unknown match request "%s"' % code)