feat: Require Ruby 2.5 or later

Signed-off-by: Daniel Azuma <dazuma@google.com>

Author: dazuma

.github/workflows/ci.yml

@@ -15,8 +15,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - os: ubuntu-latest
-            ruby: "2.4"
           - os: ubuntu-latest
             ruby: "2.5"
           - os: ubuntu-latest

.rubocop.yml

@@ -12,7 +12,3 @@ Naming/FileName:
   Exclude:
     - "examples/*/Gemfile"
     - ".toys/**/*.rb"
-Style/IfUnlessModifier:
-  Enabled: false
-Style/ModuleFunction:
-  Enabled: false

Gemfile

@@ -1,7 +1,7 @@
 source "https://rubygems.org"
 gemspec
 
-gem "google-style", "~> 1.24.0"
+gem "google-style", "~> 1.25.1"
 gem "minitest", "~> 5.14"
 gem "minitest-focus", "~> 1.1"
 gem "minitest-rg", "~> 5.2"

README.md

@@ -17,7 +17,7 @@ Features:
     specifications.
  *  Extensible to additional formats and protocol bindings, and future
     specification versions.
- *  Compatible with Ruby 2.4 or later, or JRuby 9.2.x or later. No runtime gem
+ *  Compatible with Ruby 2.5 or later, or JRuby 9.2.x or later. No runtime gem
     dependencies.
 
 ## Quickstart
@@ -35,7 +35,7 @@ A simple [Sinatra](https://sinatrarb.com) app that receives CloudEvents:
 ```ruby
 # examples/server/Gemfile
 source "https://rubygems.org"
-gem "cloud_events", "~> 0.1"
+gem "cloud_events", "~> 0.2"
 gem "sinatra", "~> 2.0"
 ```
 
@@ -59,7 +59,7 @@ A simple Ruby script that sends a CloudEvent:
 ```ruby
 # examples/client/Gemfile
 source "https://rubygems.org"
-gem "cloud_events", "~> 0.1"
+gem "cloud_events", "~> 0.2"
 ```
 
 ```ruby

cloud_events.gemspec

@@ -21,7 +21,7 @@ version = ::CloudEvents::VERSION
 
   spec.files = ::Dir.glob("lib/**/*.rb") + ::Dir.glob("*.md") + [".yardopts"]
   spec.require_paths = ["lib"]
-  spec.required_ruby_version = ">= 2.4.0"
+  spec.required_ruby_version = ">= 2.5"
 
   if spec.respond_to? :metadata
     spec.metadata["changelog_uri"] = "https://cloudevents.github.io/sdk-ruby/v#{version}/file.CHANGELOG.html"

lib/cloud_events/content_type.rb

@@ -140,7 +140,7 @@ def parse str
     end
 
     def consume_token str, downcase: false, error_message: nil
-      match = /^([\w!#\$%&'\*\+\.\^`\{\|\}-]+)(.*)$/.match str
+      match = /^([\w!#$%&'*+.\^`{|}-]+)(.*)$/.match str
       raise ParseError, error_message || "Expected token" unless match
       token = match[1]
       token.downcase! if downcase
@@ -203,7 +203,7 @@ def consume_comments str
     end
 
     def maybe_quote str
-      return str if /^[\w!#\$%&'\*\+\.\^`\{\|\}-]+$/ =~ str
+      return str if /^[\w!#$%&'*+.\^`{|}-]+$/ =~ str
       str = str.gsub("\\", "\\\\\\\\").gsub("\"", "\\\\\"")
       "\"#{str}\""
     end

lib/cloud_events/http_binding.rb

@@ -228,21 +228,19 @@ def encode_binary_content event
       headers = {}
       body = nil
       event.to_h.each do |key, value|
-        if key == "data"
+        case key
+        when "data"
           body = value
-        elsif key == "datacontenttype"
+        when "datacontenttype"
           headers["Content-Type"] = value
         else
           headers["CE-#{key}"] = percent_encode value
         end
       end
-      if body.is_a? ::String
-        headers["Content-Type"] ||= if body.encoding == ::Encoding.ASCII_8BIT
-                                      "application/octet-stream"
-                                    else
-                                      "text/plain; charset=#{body.encoding.name.downcase}"
-                                    end
-      elsif body.nil?
+      case body
+      when ::String
+        headers["Content-Type"] ||= string_content_type body
+      when nil
         headers.delete "Content-Type"
       else
         body = ::JSON.dump body
@@ -288,5 +286,15 @@ def percent_encode str
       end
       arr.pack "C*"
     end
+
+    private
+
+    def string_content_type str
+      if str.encoding == ::Encoding.ASCII_8BIT
+        "application/octet-stream"
+      else
+        "text/plain; charset=#{str.encoding.name.downcase}"
+      end
+    end
   end
 end

lib/cloud_events/json_format.rb

@@ -137,10 +137,9 @@ def encode_hash_structure_v0 event
       structure = event.to_h
       data = event.data
       content_type = event.data_content_type
-      if data.is_a?(::String) && !content_type.nil?
-        if content_type.subtype == "json" || content_type.subtype_format == "json"
-          structure["data"] = ::JSON.parse data rescue data
-        end
+      if data.is_a?(::String) && !content_type.nil? &&
+         (content_type.subtype == "json" || content_type.subtype_format == "json")
+        structure["data"] = ::JSON.parse data rescue data
       end
       structure
     end