refactor: Introducing Environments

Tests/StencilTests/IncludeSpec.swift

@@ -7,6 +7,7 @@ func testInclude() {
   describe("Include") {
     let path = Path(#file) + ".." + "fixtures"
     let loader = FileSystemLoader(paths: [path])
+    let environment = Environment(loader: loader)
 
     $0.describe("parsing") {
       $0.it("throws an error when no template is given") {
@@ -35,7 +36,7 @@ func testInclude() {
         do {
           _ = try node.render(Context())
         } catch {
-          try expect("\(error)") == "Template loader not in context"
+          try expect("\(error)") == "Template named `test.html` does not exist. No loaders found"
         }
       }
 
@@ -43,7 +44,7 @@ func testInclude() {
         let node = IncludeNode(templateName: Variable("\"unknown.html\""))
 
         do {
-          _ = try node.render(Context(dictionary: ["loader": loader]))
+          _ = try node.render(Context(environment: environment))
         } catch {
           try expect("\(error)".hasPrefix("Template named `unknown.html` does not exist in loader")).to.beTrue()
         }
@@ -51,7 +52,7 @@ func testInclude() {
 
       $0.it("successfully renders a found included template") {
         let node = IncludeNode(templateName: Variable("\"test.html\""))
-        let context = Context(dictionary: ["loader":loader, "target": "World"])
+        let context = Context(dictionary: ["target": "World"], environment: environment)
         let value = try node.render(context)
         try expect(value) == "Hello World!"
       }