Fix parsing of values

This fixes the problem that calling Get on simple values would fail:

    data := []byte("0")
    value, dataType, offset, err := Get(data)
    // err == "Value looks like Number/Boolean/None, but can't find its end: ',' or '}' symbol"

Author: twpayne

parser.go

@@ -31,7 +31,7 @@ func tokenEnd(data []byte) int {
 		}
 	}
 
-	return -1
+	return len(data)
 }
 
 // Find position of next character which is not whitespace

parser_test.go

@@ -39,6 +39,38 @@ type GetTest struct {
 }
 
 var getTests = []GetTest{
+	// Trivial tests
+	GetTest{
+		desc:    "read string",
+		json:    `""`,
+		isFound: true,
+		data:    ``,
+	},
+	GetTest{
+		desc:    "read number",
+		json:    `0`,
+		isFound: true,
+		data:    `0`,
+	},
+	GetTest{
+		desc:    "read object",
+		json:    `{}`,
+		isFound: true,
+		data:    `{}`,
+	},
+	GetTest{
+		desc:    "read array",
+		json:    `[]`,
+		isFound: true,
+		data:    `[]`,
+	},
+	GetTest{
+		desc:    "read boolean",
+		json:    `true`,
+		isFound: true,
+		data:    `true`,
+	},
+
 	// Found key tests
 	GetTest{
 		desc:    "handling multiple nested keys with same name",