Add some tests

Author: djbe

Tests/StencilTests/VariableSpec.swift

@@ -188,6 +188,70 @@ func testVariable() {
       let result = try variable.resolve(context) as? Int
       try expect(result) == 2
     }
+
+    $0.describe("Indirection") {
+      $0.it("can resolve an indirect variable") {
+        try context.push(dictionary: ["property": "name"]) {
+          let variable = Variable("$property")
+          let result = try variable.resolve(context) as? String
+          try expect(result) == "Kyle"
+        }
+      }
+
+      $0.it("can resolve an indirect variable via reflection") {
+        try context.push(dictionary: ["property": "name"]) {
+          let variable = Variable("article.author.$property")
+          let result = try variable.resolve(context) as? String
+          try expect(result) == "Kyle"
+        }
+      }
+
+      $0.it("can resolve an item from an array via it's indirect index") {
+        try context.push(dictionary: ["property": 0]) {
+          let variable = Variable("contacts.$property")
+          let result = try variable.resolve(context) as? String
+          try expect(result) == "Katie"
+        }
+      }
+
+      $0.it("can resolve an item from an array via unknown index") {
+        try context.push(dictionary: ["property": 5]) {
+          let variable = Variable("contacts.$property")
+          let result = try variable.resolve(context) as? String
+          try expect(result).to.beNil()
+        }
+      }
+
+#if os(OSX)
+      $0.it("can resolve an indirect variable via KVO") {
+        try context.push(dictionary: ["property": "name"]) {
+          let variable = Variable("object.$property")
+          let result = try variable.resolve(context) as? String
+          try expect(result) == "Foo"
+        }
+      }
+#endif
+
+      $0.it("can resolve a value via reflection") {
+        try context.push(dictionary: ["property": "articles"]) {
+          let variable = Variable("blog.$property.0.author.name")
+          let result = try variable.resolve(context) as? String
+          try expect(result) == "Kyle"
+        }
+      }
+
+      $0.it("can resolve multiple indirections") {
+        try context.push(dictionary: [
+          "prop1": "articles",
+          "prop2": 0,
+          "prop3": "name"
+        ]) {
+          let variable = Variable("blog.$prop1.$prop2.author.$prop3")
+          let result = try variable.resolve(context) as? String
+          try expect(result) == "Kyle" 
+        }
+      }
+    }
   }
 
   describe("RangeVariable") {