Fix bool parsing bug

Author: danielgtaylor

betterproto/__init__.py

@@ -595,6 +595,9 @@ def _postprocess_single(
             elif meta.proto_type in [TYPE_SINT32, TYPE_SINT64]:
                 # Undo zig-zag encoding
                 value = (value >> 1) ^ (-(value & 1))
+            elif meta.proto_type == TYPE_BOOL:
+                # Booleans use a varint encoding, so convert it to true/false.
+                value = value > 0
         elif wire_type in [WIRE_FIXED_32, WIRE_FIXED_64]:
             fmt = _pack_fmt(meta.proto_type)
             value = struct.unpack(fmt, value)[0]

betterproto/tests/bool.json

@@ -0,0 +1,3 @@
+{
+  "value": true
+}

betterproto/tests/bool.proto

@@ -0,0 +1,5 @@
+syntax = "proto3";
+
+message Test {
+    bool value = 1;
+}