Ensure for events containing multiValueHeaders, the Rack::Headers return object is correctly initialised

CHANGELOG.md

@@ -1,3 +1,8 @@
+# 2.0.1
+
+- Correctly initialise `Rack::Headers` instance for events containing `multiValueHeaders`
+  _Matthew Pickin_
+
 # 2.0.0
 
 - Add support for Rack v3 (#44)

lib/serverless_rack.rb

@@ -65,11 +65,11 @@ def parse_body(event)
 
 def parse_headers(event)
   if event.include? 'multiValueHeaders'
-    Rack::Headers.new(
+    Rack::Headers[
       (event['multiValueHeaders'] || {}).transform_values do |value|
         value.join("\n")
       end
-    )
+    ]
   else
     Rack::Headers[event['headers'] || {}]
   end

serverless-rack.gemspec

@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |s|
   s.name        = 'serverless-rack'
-  s.version     = '2.0.0'
+  s.version     = '2.0.1'
   s.summary     =
     'Serverless plugin to deploy Ruby Rack applications (Sinatra/Padrino/Cuba etc.) ' \
     'and bundle gems'

spec/parse_headers_spec.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require_relative '../lib/serverless_rack'
+
+RSpec.describe 'parse_headers' do
+  let(:event) do
+    {
+      'headers' => {
+        'Header1' => 'value1',
+        'HEADER2' => 'value2'
+      }
+    }
+  end
+
+  it 'responds to lower-case keys', :aggregate_failures do
+    parsed_headers = parse_headers(event)
+
+    expect(parsed_headers['header1']).to eq 'value1'
+    expect(parsed_headers['Header2']).to eq 'value2'
+  end
+
+  context 'with multiValuedHeaders' do
+    let(:event) do
+      {
+        'multiValueHeaders' => {
+          'Header1' => %w[value1 value2],
+          'HEADER2' => ['value3']
+        }
+      }
+    end
+
+    it 'joins the multi-value headers into a string' do
+      expect(parse_headers(event)['Header1']).to eq "value1\nvalue2"
+    end
+
+    it 'responds to lower-case keys' do
+      expect(parse_headers(event)['header2']).to eq 'value3'
+    end
+  end
+end