From ec0e5a190a4b165bf8b65801fa9e67fd9b15a60c Mon Sep 17 00:00:00 2001
From: Joey Yakimowich-Payne <jyapayne@gmail.com>
Date: Sat, 14 Mar 2020 21:00:19 -0600
Subject: [PATCH] Add tests, fix unsigned int

---
 protobuf_serialization.nim   | 34 +++++++++++++-------------
 tests/config.nims            |  2 +-
 tests/test_serialization.nim | 46 ++++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 18 deletions(-)
 create mode 100644 tests/test_serialization.nim

diff --git a/protobuf_serialization.nim b/protobuf_serialization.nim
index 8cbf33b..e31be9a 100644
--- a/protobuf_serialization.nim
+++ b/protobuf_serialization.nim
@@ -41,6 +41,9 @@ proc encode*(): ProtoBuffer =
 proc decode*[T](source: ProtoBuffer): T =
   discard
 
+proc output*(proto: ProtoBuffer): seq[byte] {.inline.} =
+  proto.outstream.getOutput
+
 template wireType(firstByte: byte): ProtoWireType =
   (firstByte and 0b111).ProtoWireType
 
@@ -73,11 +76,11 @@ proc encodeVarint(stream: OutputStreamVar, fieldNum: int, value: SomeVarint) {.i
     value = value shr 7
   stream.append byte(value and 0b1111_1111)
 
-proc encode(protobuf: ProtoBuffer, value: SomeVarint) {.inline.} =
+proc encode*(protobuf: ProtoBuffer, value: SomeVarint) {.inline.} =
   protobuf.outstream.encodeVarint(protobuf.fieldNum, value)
   inc protobuf.fieldNum
 
-proc decode[T: SomeVarint](bytes: var seq[byte], ty: typedesc[T], offset = 0): tuple[fieldNum: uint, value: T] {.inline.} =
+proc decode*[T: SomeVarint](bytes: var seq[byte], ty: typedesc[T], offset = 0): tuple[fieldNum: uint, value: T, bytesProcessed: int] {.inline.} =
   # Only up to 128 bits supported by the spec
   assert (bytes.len - 1) <= 16
 
@@ -86,28 +89,25 @@ proc decode[T: SomeVarint](bytes: var seq[byte], ty: typedesc[T], offset = 0): t
     raise newException(Exception, "Not a varint!")
 
   result.fieldNum = fieldNumber(bytes[offset])
-  result.value = cast[ty](0)
+  when T is enum:
+    var value: type(ord(result.value))
+  else:
+    var value: T
   var shiftAmount = 0
   var i = offset + 1
   while true:
-    result.value += T(bytes[i] and 0b0111_1111) shl shiftAmount
+    value += type(value)(bytes[i] and 0b0111_1111) shl shiftAmount
     shiftAmount += 7
     if (bytes[i] shr 7) == 0:
       break
     i += 1
 
+  result.bytesProcessed = i + 1
+
   when ty is SomeSVarint:
-    if (result.value and T(1)) != T(0):
-      result.value = cast[T](not(result.value shr T(1)))
+    if (value and type(value)(1)) != type(value)(0):
+      result.value = cast[T](not(value shr type(value)(1)))
     else:
-      result.value = cast[T](result.value shr T(1))
-
-proc main() =
-  let proto = newProtoBuffer()
-  proto.encode(-1500000)
-  var input: seq[byte] = proto.outstream.getOutput
-  echo input
-
-  echo decode(input, int64)
-
-main()
\ No newline at end of file
+      result.value = cast[T](value shr type(value)(1))
+  else:
+    result.value = value
\ No newline at end of file
diff --git a/tests/config.nims b/tests/config.nims
index 3bb69f8..e355636 100644
--- a/tests/config.nims
+++ b/tests/config.nims
@@ -1 +1 @@
-switch("path", "$projectDir/../src")
\ No newline at end of file
+switch("path", "$projectDir/../")
\ No newline at end of file
diff --git a/tests/test_serialization.nim b/tests/test_serialization.nim
new file mode 100644
index 0000000..1ee0a57
--- /dev/null
+++ b/tests/test_serialization.nim
@@ -0,0 +1,46 @@
+import unittest
+
+import protobuf_serialization
+
+type
+  MyEnum = enum
+    ME1, ME2, ME3
+
+suite "Test Varint Encoding":
+  test "Can encode enum":
+    let proto = newProtoBuffer()
+    proto.encode(ME3)
+    proto.encode(ME2)
+    var output = proto.output
+    assert output == @[8.byte, 4, 16, 2]
+
+    let decodedME3 = decode(output, MyEnum)
+    assert decodedME3.value == ME3
+    assert decodedME3.fieldNum == 1
+
+    let decodedME2 = decode(output, MyEnum, offset=decodedME3.bytesProcessed)
+    assert decodedME2.value == ME2
+    assert decodedME2.fieldNum == 2
+
+  test "Can encode negative number":
+    let proto = newProtoBuffer()
+    let num = -153452
+    proto.encode(num)
+    var output = proto.output
+    assert output == @[8.byte, 215, 221, 18]
+
+    let decoded = decode(output, int)
+    assert decoded.value == num
+    assert decoded.fieldNum == 1
+
+  test "Can encode unsigned number":
+    let proto = newProtoBuffer()
+    let num = 123151.uint
+    proto.encode(num)
+    var output = proto.output
+    assert output == @[8.byte, 143, 194, 7]
+
+    let decoded = decode(output, uint)
+    echo decoded.value
+    assert decoded.value == num
+    assert decoded.fieldNum == 1
\ No newline at end of file