Add parsing of URI fragment representation of JSON pointer

include/rapidjson/pointer.h

@@ -25,7 +25,9 @@ enum PointerParseErrorCode {
     kPointerParseErrorNone = 0,
 
     kPointerParseErrorTokenMustBeginWithSolidus,
-    kPointerParseErrorInvalidEscape
+    kPointerParseErrorInvalidEscape,
+    kPointerParseErrorInvalidPercentEncoding,
+    kPointerParseErrorCharacterMustPercentEncode
 };
 
 template <typename ValueType, typename Allocator = CrtAllocator>
@@ -363,6 +365,12 @@ public:
     }
 
 private:
+    //! Parse a JSON String or its URI fragment representation into tokens.
+    /*!
+        \param source Either a JSON Pointer string, or its URI fragment representation. Not need to be null terminated.
+        \param length Length of the source string.
+        \note Source cannot be JSON String Representation of JSON Pointer, e.g. In "/\u0000", \u0000 will not be unescaped.
+    */
     void Parse(const Ch* source, size_t length) {
         // Create own allocator if user did not supply.
         if (!allocator_)
@@ -380,7 +388,14 @@ private:
 
         size_t i = 0;
 
-        if (length != 0 && source[i] != '/') {
+        // Detect if it is a URI fragment
+        bool uriFragment = false;
+        if (source[i] == '#') {
+            uriFragment = true;
+            i++;
+        }
+
+        if (i != length && source[i] != '/') {
             parseErrorCode_ = kPointerParseErrorTokenMustBeginWithSolidus;
             goto error;
         }
@@ -396,6 +411,31 @@ private:
             while (i < length && source[i] != '/') {
                 Ch c = source[i++];
 
+                if (uriFragment) {
+                    // Decoding percent-encoding for URI fragment
+                    if (c == '%') {
+                        c = 0;
+                        for (int j = 0; j < 2; j++) {
+                            c <<= 4;
+                            Ch h = source[i];
+                            if      (h >= '0' && h <= '9') c += h - '0';
+                            else if (h >= 'A' && h <= 'F') c += h - 'A' + 10;
+                            else if (h >= 'a' && h <= 'f') c += h - 'a' + 10;
+                            else {
+                                parseErrorCode_ = kPointerParseErrorInvalidPercentEncoding;
+                                goto error;
+                            }
+                            i++;
+                        }
+                    }
+                    else if (!((c >= '0' && c <= '9') || (c >= 'A' && c <='Z') || (c >= 'a' && c <= 'z') || c == '-' || c == '.' || c == '_' || c =='~')) {
+                        // RFC 3986 2.3 Unreserved Characters
+                        i--;
+                        parseErrorCode_ = kPointerParseErrorCharacterMustPercentEncode;
+                        goto error;
+                    }
+                }
+                
                 // Escaping "~0" -> '~', "~1" -> '/'
                 if (c == '~') {
                     if (i < length) {

test/unittest/pointertest.cpp

@@ -165,6 +165,184 @@ TEST(Pointer, Parse) {
     }
 }
 
+TEST(Pointer, Parse_URIFragment) {
+    {
+        Pointer p("#");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(0u, p.GetTokenCount());
+    }
+
+    {
+        Pointer p("#/foo");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_EQ(3u, p.GetTokens()[0].length);
+        EXPECT_STREQ("foo", p.GetTokens()[0].name);
+    }
+
+    {
+        Pointer p("#/foo/0");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(2u, p.GetTokenCount());
+        EXPECT_EQ(3u, p.GetTokens()[0].length);
+        EXPECT_STREQ("foo", p.GetTokens()[0].name);
+        EXPECT_EQ(1u, p.GetTokens()[1].length);
+        EXPECT_STREQ("0", p.GetTokens()[1].name);
+        EXPECT_EQ(0u, p.GetTokens()[1].index);
+    }
+
+    {
+        // Unescape ~1
+        Pointer p("#/a~1b");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_EQ(3u, p.GetTokens()[0].length);
+        EXPECT_STREQ("a/b", p.GetTokens()[0].name);
+    }
+
+    {
+        // Unescape ~0
+        Pointer p("#/m~0n");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_EQ(3u, p.GetTokens()[0].length);
+        EXPECT_STREQ("m~n", p.GetTokens()[0].name);
+    }
+
+    {
+        // empty name
+        Pointer p("#/");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_EQ(0u, p.GetTokens()[0].length);
+        EXPECT_STREQ("", p.GetTokens()[0].name);
+    }
+
+    {
+        // empty and non-empty name
+        Pointer p("#//a");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(2u, p.GetTokenCount());
+        EXPECT_EQ(0u, p.GetTokens()[0].length);
+        EXPECT_STREQ("", p.GetTokens()[0].name);
+        EXPECT_EQ(1u, p.GetTokens()[1].length);
+        EXPECT_STREQ("a", p.GetTokens()[1].name);
+    }
+
+    {
+        // Null characters
+        Pointer p("#/%00%00");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_EQ(2u, p.GetTokens()[0].length);
+        EXPECT_EQ('\0', p.GetTokens()[0].name[0]);
+        EXPECT_EQ('\0', p.GetTokens()[0].name[1]);
+        EXPECT_EQ('\0', p.GetTokens()[0].name[2]);
+    }
+
+    {
+        // Percentage Escapes
+        EXPECT_STREQ("c%d", Pointer("#/c%25d").GetTokens()[0].name);
+        EXPECT_STREQ("e^f", Pointer("#/e%5Ef").GetTokens()[0].name);
+        EXPECT_STREQ("g|h", Pointer("#/g%7Ch").GetTokens()[0].name);
+        EXPECT_STREQ("i\\j", Pointer("#/i%5Cj").GetTokens()[0].name);
+        EXPECT_STREQ("k\"l", Pointer("#/k%22l").GetTokens()[0].name);
+        EXPECT_STREQ(" ", Pointer("#/%20").GetTokens()[0].name);
+    }
+
+    {
+        // Valid index
+        Pointer p("#/123");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_STREQ("123", p.GetTokens()[0].name);
+        EXPECT_EQ(123u, p.GetTokens()[0].index);
+    }
+
+    {
+        // Invalid index (with leading zero)
+        Pointer p("#/01");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_STREQ("01", p.GetTokens()[0].name);
+        EXPECT_EQ(kPointerInvalidIndex, p.GetTokens()[0].index);
+    }
+
+    if (sizeof(SizeType) == 4) {
+        // Invalid index (overflow)
+        Pointer p("#/4294967296");
+        EXPECT_TRUE(p.IsValid());
+        EXPECT_EQ(1u, p.GetTokenCount());
+        EXPECT_STREQ("4294967296", p.GetTokens()[0].name);
+        EXPECT_EQ(kPointerInvalidIndex, p.GetTokens()[0].index);
+    }
+
+    {
+        // kPointerParseErrorTokenMustBeginWithSolidus
+        Pointer p("# ");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorTokenMustBeginWithSolidus, p.GetParseErrorCode());
+        EXPECT_EQ(1u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorInvalidEscape
+        Pointer p("#/~");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorInvalidEscape, p.GetParseErrorCode());
+        EXPECT_EQ(3u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorInvalidEscape
+        Pointer p("#/~2");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorInvalidEscape, p.GetParseErrorCode());
+        EXPECT_EQ(3u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorInvalidPercentEncoding
+        Pointer p("#/%");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorInvalidPercentEncoding, p.GetParseErrorCode());
+        EXPECT_EQ(3u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorInvalidPercentEncoding
+        Pointer p("#/%g0");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorInvalidPercentEncoding, p.GetParseErrorCode());
+        EXPECT_EQ(3u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorInvalidPercentEncoding
+        Pointer p("#/%0g");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorInvalidPercentEncoding, p.GetParseErrorCode());
+        EXPECT_EQ(4u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorCharacterMustPercentEncode
+        Pointer p("#/ ");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorCharacterMustPercentEncode, p.GetParseErrorCode());
+        EXPECT_EQ(2u, p.GetParseErrorOffset());
+    }
+
+    {
+        // kPointerParseErrorCharacterMustPercentEncode
+        Pointer p("#/\\");
+        EXPECT_FALSE(p.IsValid());
+        EXPECT_EQ(kPointerParseErrorCharacterMustPercentEncode, p.GetParseErrorCode());
+        EXPECT_EQ(2u, p.GetParseErrorOffset());
+    }
+
+}
+
 TEST(Pointer, Stringify) {
     // Test by roundtrip
     const char* sources[] = {