Add support for keyword arguments for lanes in Ruby 3

fastlane/lib/fastlane/lane.rb

@@ -24,11 +24,19 @@ def initialize(platform: nil, name: nil, description: nil, block: nil, is_privat
       self.platform = platform
       self.name = name
       self.description = description
-      self.block = block
+      # We want to support _both_ lanes expecting a `Hash` (like `lane :foo do |options|`), and lanes expecting
+      # keyword parameters (like `lane :foo do |param1:, param2:, param3: 'default value'|`)
+      block_expects_keywords = !block.nil? && block.parameters.any? { |type, _| [:key, :keyreq].include?(type) }
+      # Conversion of the `Hash` parameters (passed by `Lane#call`) into keywords has to be explicit in Ruby 3
+      # https://www.ruby-lang.org/en/news/2019/12/12/separation-of-positional-and-keyword-arguments-in-ruby-3-0/
+      self.block = block_expects_keywords ? proc { |options| block.call(**options) } : block
       self.is_private = is_private
     end
 
     # Execute this lane
+    #
+    # @param [Hash] parameters The Hash of parameters to pass to the lane
+    #
     def call(parameters)
       block.call(parameters || {})
     end

fastlane/lib/fastlane/runner.rb

@@ -15,7 +15,7 @@ def full_lane_name
 
     # This will take care of executing **one** lane. That's when the user triggers a lane from the CLI for example
     # This method is **not** executed when switching a lane
-    # @param lane_name The name of the lane to execute
+    # @param lane The name of the lane to execute
     # @param platform The name of the platform to execute
     # @param parameters [Hash] The parameters passed from the command line to the lane
     def execute(lane, platform = nil, parameters = nil)

fastlane/spec/fixtures/fastfiles/FastfileLaneKeywordParams

@@ -0,0 +1,13 @@
+platform :ios do
+  lane :lane_no_param do
+    'No parameter'
+  end
+
+  lane :lane_hash_param do |options|
+    "name: #{options[:name].inspect}; version: #{options[:version].inspect}; interactive: #{options[:interactive].inspect}"
+  end
+
+  lane :lane_kw_params do |name:, version:, interactive: true|
+    "name: #{name.inspect}; version: #{version.inspect}; interactive: #{interactive.inspect}"
+  end
+end

fastlane/spec/runner_spec.rb

@@ -20,6 +20,7 @@
       it "doesn't show private lanes" do
         expect(@ff.runner.available_lanes).to_not(include('android such_private'))
       end
+
       describe "step_name override" do
         it "handle overriding of step_name" do
           allow(Fastlane::Actions).to receive(:execute_action).with('Let it Frame')
@@ -32,5 +33,84 @@
         end
       end
     end
+
+    describe "#execute" do
+      before do
+        @ff = Fastlane::FastFile.new('./fastlane/spec/fixtures/fastfiles/FastfileLaneKeywordParams')
+      end
+
+      context 'when a lane does not expect any parameter' do
+        it 'accepts calling the lane with no parameter' do
+          result = @ff.runner.execute(:lane_no_param, :ios)
+          expect(result).to eq('No parameter')
+        end
+
+        it 'accepts calling the lane with arbitrary (unused) parameter' do
+          result = @ff.runner.execute(:lane_no_param, :ios, { unused1: 42, unused2: true })
+          expect(result).to eq('No parameter')
+        end
+      end
+
+      context 'when a lane expects its parameters as a Hash' do
+        it 'accepts calling the lane with no parameter at all' do
+          result = @ff.runner.execute(:lane_hash_param, :ios)
+          expect(result).to eq('name: nil; version: nil; interactive: nil')
+        end
+
+        it 'accepts calling the lane with less parameters than used by the lane' do
+          result = @ff.runner.execute(:lane_hash_param, :ios, { version: '12.3' })
+          expect(result).to eq('name: nil; version: "12.3"; interactive: nil')
+        end
+
+        it 'accepts calling the lane with more parameters than used by the lane' do
+          result = @ff.runner.execute(:lane_hash_param, :ios, { name: 'test', version: '12.3', interactive: true, unused: 42 })
+          expect(result).to eq('name: "test"; version: "12.3"; interactive: true')
+        end
+      end
+
+      context 'when a lane expects its parameters as keywords' do
+        def keywords_list(list)
+          # The way keyword lists appear in error messages is different in Windows & Linux vs macOS
+          if FastlaneCore::Helper.windows? || FastlaneCore::Helper.linux?
+            list.map(&:to_s).join(', ') # On Windows and Linux, keyword names don't show the `:` prefix in error messages
+          else
+            list.map(&:inspect).join(', ') # On other platforms, they do have `:` in front or keyword names
+          end
+        end
+
+        it 'fails when calling the lane with no parameter at all' do
+          expect do
+            @ff.runner.execute(:lane_kw_params, :ios)
+          end.to raise_error(ArgumentError, "missing keywords: #{keywords_list(%i[name version])}")
+        end
+
+        it 'fails when calling the lane with some missing parameters' do
+          expect do
+            @ff.runner.execute(:lane_kw_params, :ios, { name: 'test', interactive: true })
+          end.to raise_error(ArgumentError, "missing keyword: #{keywords_list(%i[version])}")
+        end
+
+        it 'fails when calling the lane with extra parameters' do
+          expect do
+            @ff.runner.execute(:lane_kw_params, :ios, { name: 'test', version: '12.3', interactive: true, unexpected: 42 })
+          end.to raise_error(ArgumentError, "unknown keyword: #{keywords_list(%i[unexpected])}")
+        end
+
+        it 'takes all parameters into account when all are passed explicitly' do
+          result = @ff.runner.execute(:lane_kw_params, :ios, { name: 'test', version: "12.3", interactive: false })
+          expect(result).to eq('name: "test"; version: "12.3"; interactive: false')
+        end
+
+        it 'uses default values of parameters not provided explicitly' do
+          result = @ff.runner.execute(:lane_kw_params, :ios, { name: 'test', version: "12.3" })
+          expect(result).to eq('name: "test"; version: "12.3"; interactive: true')
+        end
+
+        it 'allows parameters to be provided in arbitrary order' do
+          result = @ff.runner.execute(:lane_kw_params, :ios, { version: "12.3", interactive: true, name: 'test' })
+          expect(result).to eq('name: "test"; version: "12.3"; interactive: true')
+        end
+      end
+    end
   end
 end