Raise `SerializationError`-derived type on parse failure (#50)

protobuf_serialization/codec.nim

@@ -20,7 +20,10 @@
 import
   std/[typetraits, unicode],
   faststreams,
-  stew/[leb128, endians2]
+  stew/[leb128, endians2],
+  ./types
+
+export types
 
 type
   WireKind* = enum
@@ -214,14 +217,14 @@ proc readValue*[T: SomeVarint](input: InputStream, _: type T): T =
 
   let (val, len) = uint64.fromBytes(buf)
   if buf.len == 0 or len != buf.len:
-    raise (ref ValueError)(msg: "Cannot read varint from stream")
+    raise (ref ProtobufValueError)(msg: "Cannot read varint from stream")
 
   fromUleb(val, T)
 
 proc readValue*[T: SomeFixed32 | SomeFixed64](input: InputStream, _: type T): T =
   var tmp {.noinit.}: array[sizeof(T), byte]
   if not input.readInto(tmp):
-    raise (ref ValueError)(msg: "Not enough bytes")
+    raise (ref ProtobufValueError)(msg: "Not enough bytes")
   when T is pdouble | pfloat:
     copyMem(addr result, addr tmp[0], sizeof(result))
   elif sizeof(T) == 8:
@@ -232,7 +235,7 @@ proc readValue*[T: SomeFixed32 | SomeFixed64](input: InputStream, _: type T): T
 proc readLength*(input: InputStream): int =
   let lenu32 = input.readValue(puint32)
   if uint64(lenu32) > uint64(int.high()):
-    raise (ref ValueError)(msg: "Invalid length")
+    raise (ref ProtobufValueError)(msg: "Invalid length")
   int(lenu32)
 
 proc readValue*[T: SomeLengthDelim](input: InputStream, _: type T): T =
@@ -241,7 +244,7 @@ proc readValue*[T: SomeLengthDelim](input: InputStream, _: type T): T =
     type Base = typetraits.distinctBase(T)
     let inputLen = input.len()
     if inputLen.isSome() and len > inputLen.get():
-        raise (ref ValueError)(msg: "Missing bytes: " & $len)
+        raise (ref ProtobufValueError)(msg: "Missing bytes: " & $len)
 
     Base(result).setLen(len)
     template bytes(): openArray[byte] =
@@ -250,11 +253,11 @@ proc readValue*[T: SomeLengthDelim](input: InputStream, _: type T): T =
       else:
         Base(result).toOpenArrayByte(0, len - 1)
     if not input.readInto(bytes()):
-      raise (ref ValueError)(msg: "Missing bytes: " & $len)
+      raise (ref ProtobufValueError)(msg: "Missing bytes: " & $len)
 
     when T is pstring:
       if validateUtf8(string(result)) != -1:
-        raise (ref ValueError)(msg: "String not valid UTF-8")
+        raise (ref ProtobufValueError)(msg: "String not valid UTF-8")
 
 proc readHeader*(input: InputStream): FieldHeader =
   let
@@ -262,6 +265,6 @@ proc readHeader*(input: InputStream): FieldHeader =
     wire = uint8(hdr and 0x07)
 
   if wire notin SupportedWireKinds:
-    raise (ref ValueError)(msg: "Invalid wire type")
+    raise (ref ProtobufValueError)(msg: "Invalid wire type")
 
   FieldHeader(hdr)

protobuf_serialization/reader.nim

@@ -19,7 +19,7 @@ macro unsupported(T: typed): untyped =
 template requireKind(header: FieldHeader, expected: WireKind) =
   mixin number
   if header.kind() != expected:
-    raise (ref ValueError)(
+    raise (ref ProtobufValueError)(
       msg: "Unexpected data kind " & $(header.number()) & ": " & $header.kind()  &
       ", exprected " & $expected)
 
@@ -40,7 +40,7 @@ proc readFieldInto[T: object and not Table](
 
     var tmp = newSeqUninitialized[byte](len)
     if not stream.readInto(tmp):
-      raise (ref ValueError)(msg: "not enough bytes")
+      raise (ref ProtobufValueError)(msg: "not enough bytes")
     memoryInput(tmp).readValueInternal(value)
 
 when defined(ConformanceTest):

protobuf_serialization/types.nim

@@ -12,6 +12,7 @@ type
   ProtobufReadError* = object of ProtobufError
   ProtobufEOFError* = object of ProtobufReadError
   ProtobufMessageError* = object of ProtobufReadError
+  ProtobufValueError* = object of ProtobufReadError
 
   ProtobufFlags* = enum
     VarIntLengthPrefix

tests/test_codec.nim

@@ -119,7 +119,7 @@ suite "codec test suite":
       # corrupting
       data.setLen(len(data) - 1)
 
-      expect(ValueError):
+      expect(ProtobufValueError):
         discard readValue(memoryInput(data), puint64)
 
   test "[fixed32] edge values test":
@@ -135,7 +135,7 @@ suite "codec test suite":
       var data = getFixed32EncodedValue(float32(Fixed32Values[i]))
       # corrupting
       data.setLen(len(data) - 1)
-      expect(ValueError):
+      expect(ProtobufValueError):
         discard readValue(memoryInput(data), fixed32)
 
   test "[fixed64] edge values test":
@@ -151,7 +151,7 @@ suite "codec test suite":
       var data = getFixed64EncodedValue(cast[float64](Fixed64Values[i]))
       # corrupting
       data.setLen(len(data) - 1)
-      expect(ValueError):
+      expect(ProtobufValueError):
         discard readValue(memoryInput(data), fixed64)
 
   test "[length] edge values test":
@@ -173,7 +173,7 @@ suite "codec test suite":
       # corrupting
       data.setLen(len(data) - 1)
 
-      expect(ValueError):
+      expect(ProtobufValueError):
         discard readValue(memoryInput(data), pbytes)
 
   test "Truncation":