Created a new exception for JSON failures.

This is only thrown directly by JsonTokenizer, but surfaces from JsonParser as well. I've added doc comments to hopefully make everything clear.

The exception is actually thrown by the reader within JsonTokenizer, in anticipation of keeping track of the location within the document, but that change is not within this PR.

1 files changed, 26 insertions, 16 deletions

diff --git a/csharp/src/Google.Protobuf/JsonTokenizer.cs b/csharp/src/Google.Protobuf/JsonTokenizer.cs
index 108ccebe..5ed1e449 100644
--- a/csharp/src/Google.Protobuf/JsonTokenizer.cs
+++ b/csharp/src/Google.Protobuf/JsonTokenizer.cs
@@ -88,6 +88,7 @@ namespace Google.Protobuf
         /// </remarks>
         /// <returns>The next token in the stream. This is never null.</returns>
         /// <exception cref="InvalidOperationException">This method is called after an EndDocument token has been returned</exception>
+        /// <exception cref="InvalidJsonException">The input text does not comply with RFC 7159</exception>
         internal JsonToken Next()
         {
             if (bufferedToken != null)
@@ -182,7 +183,7 @@ namespace Google.Protobuf
                         ValidateAndModifyStateForValue("Invalid state to read a number token: ");
                         return JsonToken.Value(number);
                     default:
-                        throw new InvalidProtocolBufferException("Invalid first character of token: " + next.Value);
+                        throw new InvalidJsonException("Invalid first character of token: " + next.Value);
                 }
             }
         }
@@ -191,7 +192,7 @@ namespace Google.Protobuf
         {
             if ((validStates & state) == 0)
             {
-                throw new InvalidProtocolBufferException(errorPrefix + state);
+                throw reader.CreateException(errorPrefix + state);
             }
         }
 
@@ -207,13 +208,13 @@ namespace Google.Protobuf
                 char c = reader.ReadOrFail("Unexpected end of text while reading string");
                 if (c < ' ')
                 {
-                    throw new InvalidProtocolBufferException(string.Format(CultureInfo.InvariantCulture, "Invalid character in string literal: U+{0:x4}", (int) c));
+                    throw reader.CreateException(string.Format(CultureInfo.InvariantCulture, "Invalid character in string literal: U+{0:x4}", (int) c));
                 }
                 if (c == '"')
                 {
                     if (haveHighSurrogate)
                     {
-                        throw new InvalidProtocolBufferException("Invalid use of surrogate pair code units");
+                        throw reader.CreateException("Invalid use of surrogate pair code units");
                     }
                     return value.ToString();
                 }
@@ -226,7 +227,7 @@ namespace Google.Protobuf
                 // followed by an escaped low surrogate or vice versa... and that couldn't even be represented in UTF-8.
                 if (haveHighSurrogate != char.IsLowSurrogate(c))
                 {
-                    throw new InvalidProtocolBufferException("Invalid use of surrogate pair code units");
+                    throw reader.CreateException("Invalid use of surrogate pair code units");
                 }
                 haveHighSurrogate = char.IsHighSurrogate(c);
                 value.Append(c);
@@ -260,7 +261,7 @@ namespace Google.Protobuf
                 case 'u':
                     return ReadUnicodeEscape();
                 default:
-                    throw new InvalidProtocolBufferException(string.Format(CultureInfo.InvariantCulture, "Invalid character in character escape sequence: U+{0:x4}", (int) c));
+                    throw reader.CreateException(string.Format(CultureInfo.InvariantCulture, "Invalid character in character escape sequence: U+{0:x4}", (int) c));
             }
         }
 
@@ -288,7 +289,7 @@ namespace Google.Protobuf
                 }
                 else
                 {
-                    throw new InvalidProtocolBufferException(string.Format(CultureInfo.InvariantCulture, "Invalid character in character escape sequence: U+{0:x4}", (int) c));
+                    throw reader.CreateException(string.Format(CultureInfo.InvariantCulture, "Invalid character in character escape sequence: U+{0:x4}", (int) c));
                 }
                 result = (result << 4) + nybble;
             }
@@ -306,11 +307,11 @@ namespace Google.Protobuf
                 char? next = reader.Read();
                 if (next == null)
                 {
-                    throw new InvalidProtocolBufferException("Unexpected end of text while reading literal token " + text);
+                    throw reader.CreateException("Unexpected end of text while reading literal token " + text);
                 }
                 if (next.Value != text[i])
                 {
-                    throw new InvalidProtocolBufferException("Unexpected character while reading literal token " + text);
+                    throw reader.CreateException("Unexpected character while reading literal token " + text);
                 }
             }
         }
@@ -354,7 +355,7 @@ namespace Google.Protobuf
             }
             catch (OverflowException)
             {
-                throw new InvalidProtocolBufferException("Numeric value out of range: " + builder);
+                throw reader.CreateException("Numeric value out of range: " + builder);
             }
         }
 
@@ -363,14 +364,14 @@ namespace Google.Protobuf
             char first = reader.ReadOrFail("Invalid numeric literal");
             if (first < '0' || first > '9')
             {
-                throw new InvalidProtocolBufferException("Invalid numeric literal");
+                throw reader.CreateException("Invalid numeric literal");
             }
             builder.Append(first);
             int digitCount;
             char? next = ConsumeDigits(builder, out digitCount);
             if (first == '0' && digitCount != 0)
             {
-                throw new InvalidProtocolBufferException("Invalid numeric literal: leading 0 for non-zero value.");
+                throw reader.CreateException("Invalid numeric literal: leading 0 for non-zero value.");
             }
             return next;
         }
@@ -382,7 +383,7 @@ namespace Google.Protobuf
             char? next = ConsumeDigits(builder, out digitCount);
             if (digitCount == 0)
             {
-                throw new InvalidProtocolBufferException("Invalid numeric literal: fraction with no trailing digits");
+                throw reader.CreateException("Invalid numeric literal: fraction with no trailing digits");
             }
             return next;
         }
@@ -393,7 +394,7 @@ namespace Google.Protobuf
             char? next = reader.Read();
             if (next == null)
             {
-                throw new InvalidProtocolBufferException("Invalid numeric literal: exponent with no trailing digits");
+                throw reader.CreateException("Invalid numeric literal: exponent with no trailing digits");
             }
             if (next == '-' || next == '+')
             {
@@ -407,7 +408,7 @@ namespace Google.Protobuf
             next = ConsumeDigits(builder, out digitCount);
             if (digitCount == 0)
             {
-                throw new InvalidProtocolBufferException("Invalid numeric literal: exponent without value");
+                throw reader.CreateException("Invalid numeric literal: exponent without value");
             }
             return next;
         }
@@ -615,7 +616,7 @@ namespace Google.Protobuf
                 char? next = Read();
                 if (next == null)
                 {
-                    throw new InvalidProtocolBufferException(messageOnFailure);
+                    throw CreateException(messageOnFailure);
                 }
                 return next.Value;
             }
@@ -628,6 +629,15 @@ namespace Google.Protobuf
                 }
                 nextChar = c;
             }
+
+            /// <summary>
+            /// Creates a new exception appropriate for the current state of the reader.
+            /// </summary>
+            internal InvalidJsonException CreateException(string message)
+            {
+                // TODO: Keep track of and use the location.
+                return new InvalidJsonException(message);
+            }
         }
     }
 }