swiftpm-stencil/Tests/StencilTests/FilterSpec.swift

import XCTest
import Spectre
@testable import Stencil

class FilterTests: XCTestCase {
  func testFilter() {
    describe("template filters") {
      let context: [String: Any] = ["name": "Kyle"]

      $0.it("allows you to register a custom filter") {
        let template = Template(templateString: "{{ name|repeat }}")

        let repeatExtension = Extension()
        repeatExtension.registerFilter("repeat") { (value: Any?) in
          if let value = value as? String {
            return "\(value) \(value)"
          }

          return nil
        }

        let result = try template.render(Context(dictionary: context, environment: Environment(extensions: [repeatExtension])))
        try expect(result) == "Kyle Kyle"
      }
        
      $0.it("allows you to register boolean filters") {
        let repeatExtension = Extension()
        repeatExtension.registerFilter(name: "isPositive", negativeFilterName: "isNotPositive") { (value: Any?) in
          if let value = value as? Int {
            return value > 0
          }
          return nil
        }
        
        let result = try Template(templateString: "{{ value|isPositive }}")
          .render(Context(dictionary: ["value": 1], environment: Environment(extensions: [repeatExtension])))
        try expect(result) == "true"
        
        let negativeResult = try Template(templateString: "{{ value|isNotPositive }}")
          .render(Context(dictionary: ["value": -1], environment: Environment(extensions: [repeatExtension])))
        try expect(negativeResult) == "true"
      }

      $0.it("allows you to register a custom filter which accepts single argument") {
        let template = Template(templateString: """
          {{ name|repeat:'value1, "value2"' }}
          """)

        let repeatExtension = Extension()
        repeatExtension.registerFilter("repeat") { value, arguments in
          if !arguments.isEmpty {
            return "\(value!) \(value!) with args \(arguments.first!!)"
          }

          return nil
        }

        let result = try template.render(Context(dictionary: context, environment: Environment(extensions: [repeatExtension])))
        try expect(result) == """
          Kyle Kyle with args value1, "value2"
          """
      }

      $0.it("allows you to register a custom filter which accepts several arguments") {
          let template = Template(templateString: """
            {{ name|repeat:'value"1"',"value'2'",'(key, value)' }}
            """)

          let repeatExtension = Extension()
          repeatExtension.registerFilter("repeat") { value, arguments in
              if !arguments.isEmpty {
                  return "\(value!) \(value!) with args 0: \(arguments[0]!), 1: \(arguments[1]!), 2: \(arguments[2]!)"
              }

              return nil
          }

          let result = try template.render(Context(dictionary: context, environment: Environment(extensions: [repeatExtension])))
          try expect(result) == """
            Kyle Kyle with args 0: value"1", 1: value'2', 2: (key, value)
            """
      }

      $0.it("allows you to register a custom which throws") {
        let template = Template(templateString: "{{ name|repeat }}")
        let repeatExtension = Extension()
        repeatExtension.registerFilter("repeat") { (value: Any?) in
          throw TemplateSyntaxError("No Repeat")
        }

        let context = Context(dictionary: context, environment: Environment(extensions: [repeatExtension]))
        try expect(try template.render(context)).toThrow(TemplateSyntaxError(reason: "No Repeat", token: template.tokens.first))
      }

      $0.it("allows you to override a default filter") {
        let template = Template(templateString: "{{ name|join }}")

        let repeatExtension = Extension()
        repeatExtension.registerFilter("join") { (value: Any?) in
          return "joined"
        }

        let result = try template.render(Context(dictionary: context, environment: Environment(extensions: [repeatExtension])))
        try expect(result) == "joined"
      }

      $0.it("allows whitespace in expression") {
        let template = Template(templateString: """
            {{ value | join : ", " }}
            """)
        let result = try template.render(Context(dictionary: ["value": ["One", "Two"]]))
        try expect(result) == "One, Two"
      }

      $0.it("throws when you pass arguments to simple filter") {
        let template = Template(templateString: "{{ name|uppercase:5 }}")
        try expect(try template.render(Context(dictionary: ["name": "kyle"]))).toThrow()
      }
    }

    describe("string filters") {
      $0.context("given string") {
        $0.it("transforms a string to be capitalized") {
          let template = Template(templateString: "{{ name|capitalize }}")
          let result = try template.render(Context(dictionary: ["name": "kyle"]))
          try expect(result) == "Kyle"
        }

        $0.it("transforms a string to be uppercase") {
          let template = Template(templateString: "{{ name|uppercase }}")
          let result = try template.render(Context(dictionary: ["name": "kyle"]))
          try expect(result) == "KYLE"
        }

        $0.it("transforms a string to be lowercase") {
          let template = Template(templateString: "{{ name|lowercase }}")
          let result = try template.render(Context(dictionary: ["name": "Kyle"]))
          try expect(result) == "kyle"
        }
      }

      $0.context("given array of strings") {
        $0.it("transforms a string to be capitalized") {
          let template = Template(templateString: "{{ names|capitalize }}")
          let result = try template.render(Context(dictionary: ["names": ["kyle", "kyle"]]))
          try expect(result) == """
            ["Kyle", "Kyle"]
            """
        }

        $0.it("transforms a string to be uppercase") {
          let template = Template(templateString: "{{ names|uppercase }}")
          let result = try template.render(Context(dictionary: ["names": ["kyle", "kyle"]]))
          try expect(result) == """
            ["KYLE", "KYLE"]
            """
        }

        $0.it("transforms a string to be lowercase") {
          let template = Template(templateString: "{{ names|lowercase }}")
          let result = try template.render(Context(dictionary: ["names": ["Kyle", "Kyle"]]))
          try expect(result) == """
            ["kyle", "kyle"]
            """
        }
      }
    }

    describe("default filter") {
      let template = Template(templateString: """
        Hello {{ name|default:"World" }}
        """)

      $0.it("shows the variable value") {
        let result = try template.render(Context(dictionary: ["name": "Kyle"]))
        try expect(result) == "Hello Kyle"
      }

      $0.it("shows the default value") {
        let result = try template.render(Context(dictionary: [:]))
        try expect(result) == "Hello World"
      }

      $0.it("supports multiple defaults") {
        let template = Template(templateString: """
          Hello {{ name|default:a,b,c,"World" }}
          """)
        let result = try template.render(Context(dictionary: [:]))
        try expect(result) == "Hello World"
      }

      $0.it("can use int as default") {
        let template = Template(templateString: "{{ value|default:1 }}")
        let result = try template.render(Context(dictionary: [:]))
        try expect(result) == "1"
      }

      $0.it("can use float as default") {
        let template = Template(templateString: "{{ value|default:1.5 }}")
        let result = try template.render(Context(dictionary: [:]))
        try expect(result) == "1.5"
      }

      $0.it("checks for underlying nil value correctly") {
        let template = Template(templateString: """
          Hello {{ user.name|default:"anonymous" }}
          """)
        let nilName: String? = nil
        let user: [String: Any?] = ["name": nilName]
        let result = try template.render(Context(dictionary: ["user": user]))
        try expect(result) == "Hello anonymous"
      }
    }

    describe("join filter") {
      let template = Template(templateString: """
        {{ value|join:", " }}
        """)

      $0.it("joins a collection of strings") {
        let result = try template.render(Context(dictionary: ["value": ["One", "Two"]]))
        try expect(result) == "One, Two"
      }

      $0.it("joins a mixed-type collection") {
        let result = try template.render(Context(dictionary: ["value": ["One", 2, true, 10.5, "Five"]]))
        try expect(result) == "One, 2, true, 10.5, Five"
      }

      $0.it("can join by non string") {
        let template = Template(templateString: """
          {{ value|join:separator }}
          """)
        let result = try template.render(Context(dictionary: ["value": ["One", "Two"], "separator": true]))
        try expect(result) == "OnetrueTwo"
      }

      $0.it("can join without arguments") {
        let template = Template(templateString: """
          {{ value|join }}
          """)
        let result = try template.render(Context(dictionary: ["value": ["One", "Two"]]))
        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"]
          """
      }
    }


    describe("filter suggestion") {
      var template: Template!
      var filterExtension: Extension!

      func expectedSyntaxError(token: String, template: Template, description: String) -> TemplateSyntaxError {
        guard let range = template.templateString.range(of: token) else {
          fatalError("Can't find '\(token)' in '\(template)'")
        }
        let lexer = Lexer(templateString: template.templateString)
        let location = lexer.rangeLocation(range)
        let sourceMap = SourceMap(filename: template.name, location: location)
        let token = Token.block(value: token, at: sourceMap)
        return TemplateSyntaxError(reason: description, token: token, stackTrace: [])
      }

      func expectError(reason: String, token: String,
                       file: String = #file, line: Int = #line, function: String = #function) throws {
        let expectedError = expectedSyntaxError(token: token, template: template, description: reason)
        let environment = Environment(extensions: [filterExtension])

        let error = try expect(environment.render(template: template, context: [:]),
                               file: file, line: line, function: function).toThrow() as TemplateSyntaxError
        let reporter = SimpleErrorReporter()
        try expect(reporter.renderError(error), file: file, line: line, function: function) == reporter.renderError(expectedError)
      }

      $0.it("made for unknown filter") {
        template = Template(templateString: "{{ value|unknownFilter }}")

        filterExtension = Extension()
        filterExtension.registerFilter("knownFilter") { value, _ in value }

        try expectError(reason: "Unknown filter 'unknownFilter'. Found similar filters: 'knownFilter'.", token: "value|unknownFilter")
      }

      $0.it("made for multiple similar filters") {
        template = Template(templateString: "{{ value|lowerFirst }}")

        filterExtension = Extension()
        filterExtension.registerFilter("lowerFirstWord") { value, _ in value }
        filterExtension.registerFilter("lowerFirstLetter") { value, _ in value }

        try expectError(reason: "Unknown filter 'lowerFirst'. Found similar filters: 'lowerFirstWord', 'lowercase'.", token: "value|lowerFirst")
      }

      $0.it("not made when can't find similar filter") {
        template = Template(templateString: "{{ value|unknownFilter }}")
        try expectError(reason: "Unknown filter 'unknownFilter'. Found similar filters: 'lowerFirstWord'.", token: "value|unknownFilter")
      }

    }


    describe("indent filter") {
      $0.it("indents content") {
        let template = Template(templateString: """
          {{ value|indent:2 }}
          """)
        let result = try template.render(Context(dictionary: ["value": """
          One
          Two
          """]))
        try expect(result) == """
          One
            Two
          """
      }

      $0.it("can indent with arbitrary character") {
        let template = Template(templateString: """
          {{ value|indent:2,"\t" }}
          """)
        let result = try template.render(Context(dictionary: ["value": """
          One
          Two
          """]))
        try expect(result) == """
          One
          \t\tTwo
          """
      }

      $0.it("can indent first line") {
        let template = Template(templateString: """
          {{ value|indent:2," ",true }}
          """)
        let result = try template.render(Context(dictionary: ["value": """
          One
          Two
          """]))
        try expect(result) == """
            One
            Two
          """
      }

      $0.it("does not indent empty lines") {
        let template = Template(templateString: """
          {{ value|indent }}
          """)
        let result = try template.render(Context(dictionary: ["value": """
          One


          Two


          """]))
        try expect(result) == """
          One


              Two


          """
      }
    }
  }

  describe("dynamic filter") {
    
    $0.it("can apply dynamic filter") {
      let template = Template(templateString: "{{ name|filter:somefilter }}")
      let result = try template.render(Context(dictionary: ["name": "Jhon", "somefilter": "uppercase"]))
      try expect(result) == "JHON"
    }
    
    $0.it("can apply dynamic filter on array") {
      let template = Template(templateString: "{{ values|filter:joinfilter }}")
      let result = try template.render(Context(dictionary: ["values": [1, 2, 3], "joinfilter": "join:\", \""]))
      try expect(result) == "1, 2, 3"
    }
    
    $0.it("throws on unknown dynamic filter") {
      let template = Template(templateString: "{{ values|filter:unknown }}")
      let context = Context(dictionary: ["values": [1, 2, 3], "unknown": "absurd"])
      try expect(try template.render(context)).toThrow()
    }
    
  }

}