feat(options): Add support for variadic options (#38)

Author: djbe

CHANGELOG.md

@@ -1,6 +1,12 @@
 # Commander Changelog
 
+## unreleased
+
+### Enhancements
+
 - Renamed VaradicArgument to VariadicArgument.
+- Adds support for variadic options, allowing the user to repeat options to
+  provide additional values.
 
 ## 0.5.0
 

README.md

@@ -120,7 +120,8 @@ Hello Kyle
 ##### Types of descriptors
 
 - Option - An optional option with a value.
-- Options - A option with a value which can be used multiple times, your command is passed an array containing all option values.
+- Options - A option with a value which can be used multiple times, your command is passed an array containing all option values. You need to specify ahead of time how many values you expect. Example: `--myOption value1 value2 value3` 
+- VariadicOption - Same as options, but instead of a fixed `count` of values, the user can just repeat the option with additional values. Example: `--myOption value1 --myOption value2`  
 - Flag - A boolean, on/off flag.
 - Argument - A positional argument.
 - VariadicArgument - A variadic argument

Sources/ArgumentDescription.swift

@@ -155,6 +155,37 @@ open class Options<T : ArgumentConvertible> : ArgumentDescriptor {
 }
 
 
+open class VaradicOption<T : ArgumentConvertible> : ArgumentDescriptor {
+  public typealias ValueType = [T]
+
+  open let name:String
+  open let description:String?
+  open let `default`:ValueType
+  open var type:ArgumentType { return .option }
+
+  public init(_ name:String, _ default:ValueType = [], description:String? = nil) {
+    self.name = name
+    self.`default` = `default`
+    self.description = description
+  }
+
+  open func parse(_ parser:ArgumentParser) throws -> ValueType {
+    var values: ValueType? = nil
+
+    while let shifted = try parser.shiftValueForOption(name) {
+      let argument = try T(string: shifted)
+
+      if values == nil {
+        values = ValueType()
+      }
+      values?.append(argument)
+    }
+
+    return values ?? `default`
+  }
+}
+
+
 open class Flag : ArgumentDescriptor {
   public typealias ValueType = Bool
 

Tests/CommanderTests/ArgumentParserSpec.swift

@@ -7,7 +7,7 @@ public func testArgumentParser() {
     var parser: ArgumentParser!
 
     $0.before {
-      parser = ArgumentParser(arguments: ["first", "-f", "--verbose", "middle", "end"])
+      parser = ArgumentParser(arguments: ["first", "-f", "--verbose", "middle", "end", "--varOption", "varValue1", "--varOption", "varValue2"])
     }
 
     $0.describe("shifting") {
@@ -87,5 +87,21 @@ public func testArgumentParser() {
         try expect(value?.last) == "end"
       }
     }
+
+    $0.describe("variadic options") {
+      $0.it("should return arguments for option") {
+        let option = VaradicOption<String>("varOption")
+        let values = try option.parse(parser)
+        try expect(values.count) == 2
+        try expect(values.first) == "varValue1"
+        try expect(values.last) == "varValue2"
+      }
+
+      $0.it("should return empty array when option is unknown") {
+        let option = VaradicOption<String>("unknown")
+        let values = try option.parse(parser)
+        try expect(values.count) == 0
+      }
+    }
   }
 }