Merge pull request #242 from stencilproject/feature/deterministic-for-loop

Deterministic `for` loops for dictionaries

CHANGELOG.md

@@ -7,6 +7,9 @@
 - Now accessing undefined keys in NSObject does not cause runtime crash and instead renders empty string.  
   [Ilya Puchka](https://github.com/ilyapuchka)
   [#234](https://github.com/stencilproject/Stencil/pull/234)
+- `for` tag: When iterating over a dictionary the keys will now always be sorted (in an ascending order) to ensure consistent output generation.  
+  [David Jennes](https://github.com/djbe)
+  [#240](https://github.com/stencilproject/Stencil/pull/240)
 
 ### Breaking Changes
 

Sources/ForTag.swift

@@ -93,7 +93,7 @@ class ForNode : NodeType {
     var values: [Any]
 
     if let dictionary = resolved as? [String: Any], !dictionary.isEmpty {
-      values = dictionary.map { ($0.key, $0.value) }
+      values = dictionary.sorted { $0.key < $1.key }
     } else if let array = resolved as? [Any] {
       values = array
     } else if let range = resolved as? CountableClosedRange<Int> {

Tests/StencilTests/ForNodeSpec.swift

@@ -209,8 +209,9 @@ func testForNode() {
       let template = Template(templateString: templateString)
       let result = try template.render(context)
 
-      let sortedResult = result.split(separator: ",").map(String.init).sorted(by: <)
-      try expect(sortedResult) == ["one: I", "two: II"]
+      try expect(result) == """
+        one: I,two: II,
+        """
     }
 
     $0.it("renders supports iterating over dictionary") {
@@ -222,8 +223,9 @@ func testForNode() {
       let node = ForNode(resolvable: Variable("dict"), loopVariables: ["key"], nodes: nodes, emptyNodes: emptyNodes, where: nil)
       let result = try node.render(context)
 
-      let sortedResult = result.split(separator: ",").map(String.init).sorted(by: <)
-      try expect(sortedResult) == ["one", "two"]
+      try expect(result) == """
+        one,two,
+        """
     }
 
     $0.it("renders supports iterating over dictionary") {
@@ -235,11 +237,11 @@ func testForNode() {
         ]
       let emptyNodes: [NodeType] = [TextNode(text: "empty")]
       let node = ForNode(resolvable: Variable("dict"), loopVariables: ["key", "value"], nodes: nodes, emptyNodes: emptyNodes, where: nil)
-
       let result = try node.render(context)
 
-      let sortedResult = result.split(separator: ",").map(String.init).sorted(by: <)
-      try expect(sortedResult) == ["one=I", "two=II"]
+      try expect(result) == """
+        one=I,two=II,
+        """
     }
 
     $0.it("handles invalid input") {