feat: added split fitler (#187)

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Added support for resolving superclass properties for not-NSObject subclasses
 - The `{% for %}` tag can now iterate over tuples, structures and classes via
   their stored properties.
+- Added `split` filter
 
 ### Bug Fixes
 

Sources/Extension.swift

@@ -57,6 +57,7 @@ class DefaultExtension: Extension {
     registerFilter("uppercase", filter: uppercase)
     registerFilter("lowercase", filter: lowercase)
     registerFilter("join", filter: joinFilter)
+    registerFilter("split", filter: splitFilter)
   }
 }
 

Sources/Filters.swift

@@ -40,3 +40,16 @@ func joinFilter(value: Any?, arguments: [Any?]) throws -> Any? {
 
   return value
 }
+
+func splitFilter(value: Any?, arguments: [Any?]) throws -> Any? {
+  guard arguments.count < 2 else {
+    throw TemplateSyntaxError("'split' filter takes a single argument")
+  }
+
+  let separator = stringify(arguments.first ?? " ")
+  if let value = value as? String {
+    return value.components(separatedBy: separator)
+  }
+
+  return value
+}

Tests/StencilTests/FilterSpec.swift

@@ -183,4 +183,20 @@ func testFilter() {
       try expect(result) == "OneTwo"
     }
   }
+
+  describe("split filter") {
+    let template = Template(templateString: "{{ value|split:\", \" }}")
+
+    $0.it("split a string into array") {
+      let result = try template.render(Context(dictionary: ["value": "One, Two"]))
+      try expect(result) == "[\"One\", \"Two\"]"
+    }
+
+    $0.it("can split without arguments") {
+      let template = Template(templateString: "{{ value|split }}")
+      let result = try template.render(Context(dictionary: ["value": "One, Two"]))
+      try expect(result) == "[\"One,\", \"Two\"]"
+    }
+  }
+
 }