[InlineData(@"{p1:regex(([{{(])\w+)}", @"regex(([{(])\w+)")] // Not balanced {
public void Parse_RegularExpressions(string template, string constraint)
{
// Arrange
var builder = RoutePatternBuilder.Create(template);
builder.AddPathSegmentFromText(
template,
RoutePatternPart.CreateParameterFromText(
template,
"p1",
null,
RoutePatternParameterKind.Standard,
ConstraintReference.CreateFromText(constraint, constraint)));
var expected = builder.Build();
// Act
var actual = RoutePatternParser.Parse(template);
// Assert
Assert.Equal <RoutePattern>(expected, actual, new RoutePatternEqualityComparer());
}
private static ConstraintParseResults ParseConstraints(
string parameter,
int currentIndex,
int endIndex)
{
var constraints = new List <ConstraintReference>();
var state = ParseState.Start;
var startIndex = currentIndex;
do
{
var currentChar = currentIndex > endIndex ? null : (char?)parameter[currentIndex];
switch (state)
{
case ParseState.Start:
switch (currentChar)
{
case null:
state = ParseState.End;
break;
case ':':
state = ParseState.ParsingName;
startIndex = currentIndex + 1;
break;
case '(':
state = ParseState.InsideParenthesis;
break;
case '=':
state = ParseState.End;
currentIndex--;
break;
}
break;
case ParseState.InsideParenthesis:
switch (currentChar)
{
case null:
state = ParseState.End;
var constraintText = parameter.Substring(startIndex, currentIndex - startIndex);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
break;
case ')':
// Only consume a ')' token if
// (a) it is the last token
// (b) the next character is the start of the new constraint ':'
// (c) the next character is the start of the default value.
var nextChar = currentIndex + 1 > endIndex ? null : (char?)parameter[currentIndex + 1];
switch (nextChar)
{
case null:
state = ParseState.End;
constraintText = parameter.Substring(startIndex, currentIndex - startIndex + 1);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
break;
case ':':
state = ParseState.Start;
constraintText = parameter.Substring(startIndex, currentIndex - startIndex + 1);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
startIndex = currentIndex + 1;
break;
case '=':
state = ParseState.End;
constraintText = parameter.Substring(startIndex, currentIndex - startIndex + 1);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
break;
}
break;
case ':':
case '=':
// In the original implementation, the Regex would've backtracked if it encountered an
// unbalanced opening bracket followed by (not necessarily immediatiely) a delimiter.
// Simply verifying that the parantheses will eventually be closed should suffice to
// determine if the terminator needs to be consumed as part of the current constraint
// specification.
var indexOfClosingParantheses = parameter.IndexOf(')', currentIndex + 1);
if (indexOfClosingParantheses == -1)
{
constraintText = parameter.Substring(startIndex, currentIndex - startIndex);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
if (currentChar == ':')
{
state = ParseState.ParsingName;
startIndex = currentIndex + 1;
}
else
{
state = ParseState.End;
currentIndex--;
}
}
else
{
currentIndex = indexOfClosingParantheses;
}
break;
}
break;
case ParseState.ParsingName:
switch (currentChar)
{
case null:
state = ParseState.End;
var constraintText = parameter.Substring(startIndex, currentIndex - startIndex);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
break;
case ':':
constraintText = parameter.Substring(startIndex, currentIndex - startIndex);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
startIndex = currentIndex + 1;
break;
case '(':
state = ParseState.InsideParenthesis;
break;
case '=':
state = ParseState.End;
constraintText = parameter.Substring(startIndex, currentIndex - startIndex);
constraints.Add(ConstraintReference.CreateFromText(constraintText, constraintText));
currentIndex--;
break;
}
break;
}
currentIndex++;
} while (state != ParseState.End);
return(new ConstraintParseResults
{
CurrentIndex = currentIndex,
Constraints = constraints
});
}