Deprecate `sizeSpec` in favor of `subtypeSpec` (#172)

This commit deprecates `subtypeSpec` attributes and keyword argument.
It is now recommended to pass `ValueSizeConstraint`, as well as all
other constraints, to `subtypeSpec`.

By way of the change mentioned above, this commit fixes a design bug
in a way of how the items assigned to constructed types are verified.
Now if `Asn1Type`-based object is assigned, its compatibility is
verified based on having all tags and constraint objects as the type
in field definition. When a bare Python value is assigned, then field
type object is cloned and initialized with the bare value (constraints
verificaton would run at this moment).

3 files changed, 71 insertions, 73 deletions

diff --git a/pyasn1/type/base.py b/pyasn1/type/base.py
index 1fd69f9..834b76e 100644
--- a/pyasn1/type/base.py
+++ b/pyasn1/type/base.py
@@ -498,17 +498,39 @@ class ConstructedAsn1Type(Asn1Type):
     strictConstraints = False
 
     componentType = None
-    sizeSpec = None
+
+    # backward compatibility, unused
+    sizeSpec = constraint.ConstraintsIntersection()
 
     def __init__(self, **kwargs):
         readOnly = {
             'componentType': self.componentType,
+            # backward compatibility, unused
             'sizeSpec': self.sizeSpec
         }
+
+        # backward compatibility: preserve legacy sizeSpec support
+        kwargs = self._moveSizeSpec(**kwargs)
+
         readOnly.update(kwargs)
 
         Asn1Type.__init__(self, **readOnly)
 
+    def _moveSizeSpec(self, **kwargs):
+        # backward compatibility, unused
+        sizeSpec = kwargs.pop('sizeSpec', self.sizeSpec)
+        if sizeSpec:
+            subtypeSpec = kwargs.pop('subtypeSpec', self.subtypeSpec)
+            if subtypeSpec:
+                subtypeSpec = sizeSpec
+
+            else:
+                subtypeSpec += sizeSpec
+
+            kwargs['subtypeSpec'] = subtypeSpec
+
+        return kwargs
+
     def __repr__(self):
         representation = '%s %s object' % (
             self.__class__.__name__, self.isValue and 'value' or 'schema'
@@ -667,7 +689,7 @@ class ConstructedAsn1Type(Asn1Type):
         :py:class:`~pyasn1.error.PyAsn1tError` on any inconsistencies found
         """
         try:
-            self.sizeSpec(self)
+            self.subtypeSpec(self)
 
         except error.PyAsn1Error:
             exc = sys.exc_info()[1]
@@ -694,9 +716,10 @@ class ConstructedAsn1Type(Asn1Type):
     def getComponentType(self):
         return self.componentType
 
+    # backward compatibility, unused
     def verifySizeSpec(self):
-        self.sizeSpec(self)
+        self.subtypeSpec(self)
 
 
-# Backward compatibility
+        # Backward compatibility
 AbstractConstructedAsn1Item = ConstructedAsn1Type
diff --git a/pyasn1/type/char.py b/pyasn1/type/char.py
index 3f8c444..06074da 100644
--- a/pyasn1/type/char.py
+++ b/pyasn1/type/char.py
@@ -39,7 +39,9 @@ class AbstractCharacterString(univ.OctetString):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     encoding: :py:class:`str`
         Unicode codec ID to encode/decode :class:`unicode` (Python 2) or
diff --git a/pyasn1/type/univ.py b/pyasn1/type/univ.py
index 4f305f6..fbf8ed5 100644
--- a/pyasn1/type/univ.py
+++ b/pyasn1/type/univ.py
@@ -47,7 +47,9 @@ class Integer(base.SimpleAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     namedValues: :py:class:`~pyasn1.type.namedval.NamedValues`
         Object representing non-default symbolic aliases for numbers
@@ -293,7 +295,9 @@ class Boolean(Integer):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s).Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     namedValues: :py:class:`~pyasn1.type.namedval.NamedValues`
         Object representing non-default symbolic aliases for numbers
@@ -377,7 +381,9 @@ class BitString(base.SimpleAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     namedValues: :py:class:`~pyasn1.type.namedval.NamedValues`
         Object representing non-default symbolic aliases for numbers
@@ -747,7 +753,9 @@ class OctetString(base.SimpleAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     encoding: :py:class:`str`
         Unicode codec ID to encode/decode :class:`unicode` (Python 2) or
@@ -1130,7 +1138,9 @@ class ObjectIdentifier(base.SimpleAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     Raises
     ------
@@ -1268,7 +1278,9 @@ class Real(base.SimpleAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     Raises
     ------
@@ -1552,7 +1564,9 @@ class Enumerated(Integer):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     namedValues: :py:class:`~pyasn1.type.namedval.NamedValues`
         Object representing non-default symbolic aliases for numbers
@@ -1620,10 +1634,9 @@ class SequenceOfAndSetOfBase(base.ConstructedAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
-
-    sizeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing collection size constraint
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type can only occur on explicit
+        `.isInconsistent` call.
 
     Examples
     --------
@@ -1645,7 +1658,7 @@ class SequenceOfAndSetOfBase(base.ConstructedAsn1Type):
         # support positional params for backward compatibility
         if args:
             for key, value in zip(('componentType', 'tagSet',
-                                   'subtypeSpec', 'sizeSpec'), args):
+                                   'subtypeSpec'), args):
                 if key in kwargs:
                     raise error.PyAsn1Error('Conflicting positional and keyword params!')
                 kwargs['componentType'] = value
@@ -1921,7 +1934,8 @@ class SequenceOfAndSetOfBase(base.ConstructedAsn1Type):
                     componentType.isSameTypeWith or
                     componentType.isSuperTypeOf)
 
-            if not subtypeChecker(value, matchTags, matchConstraints):
+            if not subtypeChecker(value, verifyConstraints and matchTags,
+                                  verifyConstraints and matchConstraints):
                 # TODO: we should wrap componentType with UnnamedType to carry
                 # additional properties associated with componentType
                 if componentType.typeId != Any.typeId:
@@ -1929,21 +1943,6 @@ class SequenceOfAndSetOfBase(base.ConstructedAsn1Type):
                         'Component value is tag-incompatible: %r vs '
                         '%r' % (value, componentType))
 
-            else:
-                if not componentType.isSuperTypeOf(
-                        value, matchTags, matchConstraints):
-                    raise error.PyAsn1Error(
-                        'Component value is tag-incompatible: '
-                        '%r vs %r' % (value, componentType))
-
-        if verifyConstraints and value.isValue:
-            try:
-                self.subtypeSpec(value, idx)
-
-            except error.PyAsn1Error:
-                exType, exValue, exTb = sys.exc_info()
-                raise exType('%s at %s' % (exValue, self.__class__.__name__))
-
         componentValues[idx] = value
 
         self._componentValues = componentValues
@@ -2063,10 +2062,6 @@ class SequenceOf(SequenceOfAndSetOfBase):
     #: imposing constraints on |ASN.1| type initialization values.
     subtypeSpec = constraint.ConstraintsIntersection()
 
-    #: Default :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-    #: object imposing size constraint on |ASN.1| objects
-    sizeSpec = constraint.ConstraintsIntersection()
-
     # Disambiguation ASN.1 types identification
     typeId = SequenceOfAndSetOfBase.getTypeId()
 
@@ -2090,10 +2085,6 @@ class SetOf(SequenceOfAndSetOfBase):
     #: imposing constraints on |ASN.1| type initialization values.
     subtypeSpec = constraint.ConstraintsIntersection()
 
-    #: Default :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-    #: object imposing size constraint on |ASN.1| objects
-    sizeSpec = constraint.ConstraintsIntersection()
-
     # Disambiguation ASN.1 types identification
     typeId = SequenceOfAndSetOfBase.getTypeId()
 
@@ -2113,10 +2104,9 @@ class SequenceAndSetBase(base.ConstructedAsn1Type):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
-
-    sizeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing collection size constraint
+        Object representing non-default ASN.1 subtype constraint(s).  Constraints
+        verification for |ASN.1| type can only occur on explicit
+        `.isInconsistent` call.
 
     Examples
     --------
@@ -2562,25 +2552,19 @@ class SequenceAndSetBase(base.ConstructedAsn1Type):
             else:
                 raise error.PyAsn1Error('%s undefined component type' % componentType.__class__.__name__)
 
-        elif (matchTags or matchConstraints) and componentTypeLen:
+        elif ((verifyConstraints or matchTags or matchConstraints) and
+              componentTypeLen):
             subComponentType = componentType.getTypeByPosition(idx)
             if subComponentType is not noValue:
                 subtypeChecker = (self.strictConstraints and
                                   subComponentType.isSameTypeWith or
                                   subComponentType.isSuperTypeOf)
 
-                if not subtypeChecker(value, matchTags, matchConstraints):
+                if not subtypeChecker(value, verifyConstraints and matchTags,
+                                      verifyConstraints and matchConstraints):
                     if not componentType[idx].openType:
                         raise error.PyAsn1Error('Component value is tag-incompatible: %r vs %r' % (value, componentType))
 
-        if verifyConstraints and value.isValue:
-            try:
-                self.subtypeSpec(value, idx)
-
-            except error.PyAsn1Error:
-                exType, exValue, exTb = sys.exc_info()
-                raise exType('%s at %s' % (exValue, self.__class__.__name__))
-
         if componentTypeLen or idx in self._dynamicNames:
             componentValues[idx] = value
 
@@ -2717,10 +2701,6 @@ class Sequence(SequenceAndSetBase):
     #: imposing constraints on |ASN.1| type initialization values.
     subtypeSpec = constraint.ConstraintsIntersection()
 
-    #: Default :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-    #: object imposing constraints on |ASN.1| objects
-    sizeSpec = constraint.ConstraintsIntersection()
-
     #: Default collection of ASN.1 types of component (e.g. :py:class:`~pyasn1.type.namedtype.NamedType`)
     #: object imposing size constraint on |ASN.1| objects
     componentType = namedtype.NamedTypes()
@@ -2760,10 +2740,6 @@ class Set(SequenceAndSetBase):
     #: imposing constraints on |ASN.1| type initialization values.
     subtypeSpec = constraint.ConstraintsIntersection()
 
-    #: Default :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-    #: object imposing constraints on |ASN.1| objects
-    sizeSpec = constraint.ConstraintsIntersection()
-
     # Disambiguation ASN.1 types identification
     typeId = SequenceAndSetBase.getTypeId()
 
@@ -2884,10 +2860,9 @@ class Choice(Set):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
-
-    sizeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing collection size constraint
+        Object representing non-default ASN.1 subtype constraint(s).  Constraints
+        verification for |ASN.1| type can only occur on explicit
+        `.isInconsistent` call.
 
     Examples
     --------
@@ -2927,11 +2902,7 @@ class Choice(Set):
     #: Set (on class, not on instance) or return a
     #: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection` object
     #: imposing constraints on |ASN.1| type initialization values.
-    subtypeSpec = constraint.ConstraintsIntersection()
-
-    #: Default :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-    #: object imposing size constraint on |ASN.1| objects
-    sizeSpec = constraint.ConstraintsIntersection(
+    subtypeSpec = constraint.ConstraintsIntersection(
         constraint.ValueSizeConstraint(1, 1)
     )
 
@@ -3197,7 +3168,9 @@ class Any(OctetString):
         Object representing non-default ASN.1 tag(s)
 
     subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
-        Object representing non-default ASN.1 subtype constraint(s)
+        Object representing non-default ASN.1 subtype constraint(s). Constraints
+        verification for |ASN.1| type occurs automatically on object
+        instantiation.
 
     encoding: :py:class:`str`
         Unicode codec ID to encode/decode :class:`unicode` (Python 2) or