Add an edge case test that . matches \\u2029 and \\u2028

[f3ath]

I-Regexp follows the XSD-2 which states that the equivalent character class for . is [^\r\n]. Some programming languages (e.g. Javascript, Dart) treat . differently, in particular it won't match Unicode chars \u2029 and \u2028. This PR introduces a corresponding edge case test.

[glyn]

Would it be possible to use \u2028 in the JSON document?

[f3ath]

Not sure I understand the question. Do you mean removing the second \? That would make the test name indistinguishable from the other one.

[glyn]

No, I was talking about using \u2028 in the "document" member.

[f3ath]

In the document it is defined as \u2028, you can see it in the source file. But it gets replaced with the actual character when the cts.json get compiled. I'm not sure if it would be possible to keep it as \uXXXX in the compiled cts.json.

[gregsdennis]

I don't think it's terribly important to have the character escaped in the doc. The only problem I could see is potentially a particularly strict JSON parser might not be able to read it.

[gregsdennis]

My implementation (which uses the .Net regex engine in an "ECMAScript" configuration) is returning the \r and \n as well.

Name:     functions, match, dot matcher on \u2028
Selector: $[?match(@, '.')]
Document: ["\u2028","\r","\n",true,[],{}]
Result:   ["\u2028"]
Results:   null
IsValid:  True

Actual (values): ["\u2028","\r","\n"]

Actual (serialized):
{
  "Matches": [
    {
      "Value": "\u2028",
      "Location": "$[0]"
    },
    {
      "Value": "\r",
      "Location": "$[1]"
    },
    {
      "Value": "\n",
      "Location": "$[2]"
    }
  ],
  "Error": null
}

Probably related to this. I have code that does some translation, but I don't think I did the "little bit of lookahead assertion added to remove \r and \n" part.

[gregsdennis]

After some googling I figured out how to add the lookahead exclusions, and the tests pass for me now.

[hiltontj]

Was able to fix this to get things passing in serde_json_path again with hiltontj/serde_json_path#92. Thanks for surfacing this one @f3ath!