Updated Stubbing and Request Matching (markdown)

Stubbing-and-Request-Matching.md

@@ -383,12 +383,91 @@ The model of the request is supplied to the header and body templates. The follo
 * `request.cookies.<key>` - Value of a request cookie e.g. request.cookies.JSESSIONID
 * `request.body` - Request body text (avoid for non-text bodies)
 
-#### Handlebars helpers
+### Handlebars helpers
 All of the standard helpers (template functions) provided by the C# Handlebars implementation plus all of the string helpers are available e.g.
 `{{capitalize request.query.search}}`
 
+### JsonPath support
+JsonPath support is also present (internal logic is based on Newtonsoft.Json).
+
+Two functions are present:
+1. JsonPath.SelectToken
+2. JsonPath.SelectTokens
+
+#### JsonPath.SelectToken
+This can be used in C# like:
+```csharp
+var server = FluentMockServer.Start();
+server
+    .Given(Request.Create().WithPath("/jsonpathtestToken").UsingPost())
+    .RespondWith(Response.Create()
+        .WithHeader("Content-Type", "application/json")
+        .WithBody("{{JsonPath.SelectToken request.body \"$.Manufacturers[?(@.Name == 'Acme Co')]\"}}")
+        .WithTransformer()
+    );
+```
+
+Or using the admin mapping file:
+``` js
+{
+    "Request": {
+        "Path": {
+            "Matchers": [
+                {
+                    "Name": "WildcardMatcher",
+                    "Pattern": "/jsonpathtestToken"
+                }
+            ]
+        },
+        "Methods": [
+            "post"
+        ]
+    },
+    "Response": {
+        "StatusCode": 200,
+        "BodyDestination": "SameAsSource",
+        "Body": "{{JsonPath.SelectToken request.body \"$.Manufacturers[?(@.Name == 'Acme Co')]\"}}",
+        "UseTransformer": true,
+        "Headers": {
+            "Content-Type": "application/json"
+        }
+    }
+}
+```
+
+Note that also replacing values in a Json Object and returning a the body as Json is supported, to use this, use a mapping file like this:
+``` js
+{
+  "Request": {
+    "Path": {
+      "Matchers": [
+        {
+          "Name": "WildcardMatcher",
+          "Pattern": "/test"
+        }
+      ]
+    },
+    "Methods": [
+      "post"
+    ]
+  },
+  "Response": {
+    "StatusCode": 200,
+    "BodyAsJson": {
+      "path": "{{request.path}}",
+      "result": "{{JsonPath.SelectToken request.bodyAsJson \"username\"}}"
+    },
+    "UseTransformer": true,
+    "Headers": {
+      "Content-Type": "application/json"
+    }
+  }
+}
+```
+
+
 ## Stub priority
-It is sometimes the case that you’ll want to declare two or more stub mappings that “overlap”, in that a given request would be a match for more than one of them.
+It is sometimes the case that you’ll want to declare two or more stub mappings that "overlap", in that a given request would be a match for more than one of them.
 
 One example of this might be where you want to define a catch-all stub for any URL that doesn’t match any more specific cases. Adding a priority to a stub mapping facilitates this: