Add RBS type signatures and Steep type checking

Author: sferik

Gemfile

@@ -19,6 +19,10 @@ group :test do
   gem "yardstick"
 end
 
+group :sig do
+  gem "steep"
+end
+
 group :doc do
   gem "kramdown"
   gem "yard"

Rakefile

@@ -23,9 +23,16 @@ Yardstick::Rake::Verify.new do |verify|
   verify.threshold = 100
 end
 
+desc "Type check with Steep"
+task :steep do
+  require "steep"
+  require "steep/cli"
+  exit Steep::CLI.new(argv: ["check", "--log-level=fatal"], stdout: $stdout, stderr: $stderr, stdin: $stdin).run
+end
+
 desc "Run mutation testing with Mutant"
 task :mutant do
   system("bundle exec mutant run") || abort("Mutant failed!")
 end
 
-task default: %i[test rubocop verify_measurements]
+task default: %i[test rubocop verify_measurements steep]

Steepfile

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+target :lib do
+  signature "sig"
+  check "lib"
+
+  library "pathname"
+  library "securerandom"
+  library "stringio"
+  library "uri"
+end

lib/http/form_data/composite_io.rb

@@ -83,7 +83,7 @@ def read_chunks(length)
 
           length -= chunk.bytesize
 
-          break if length.zero?
+          break if length == 0 # rubocop:disable Style/NumericPredicate
         end
       end
 

lib/http/form_data/multipart.rb

@@ -89,7 +89,7 @@ def tail
       # @api private
       # @return [Array<Param>]
       def parts(data)
-        params = []
+        params = [] #: Array[Param]
 
         FormData.ensure_data(data).each do |name, values|
           Array(values).each do |value|

lib/http/form_data/multipart/param.rb

@@ -60,8 +60,9 @@ def header
         # @api private
         # @return [String]
         def parameters
+          fname = filename
           parameters = { name: @name }
-          parameters[:filename] = filename if filename
+          parameters[:filename] = fname if fname
           parameters.map { |k, v| "#{k}=#{v.inspect}" }.join("; ")
         end
 

lib/http/form_data/readable.rb

@@ -13,7 +13,7 @@ module Readable
       # @return [String]
       def to_s
         rewind
-        content = read
+        content = read || ""
         rewind
         content
       end
@@ -29,7 +29,7 @@ def to_s
       # @param [String] outbuf String to be replaced with retrieved data
       # @return [String, nil]
       def read(length = nil, outbuf = nil)
-        @io.read(length, outbuf)
+        outbuf ? @io.read(length, outbuf) : @io.read(length)
       end
 
       # Returns IO size in bytes

sig/deps.rbs

@@ -0,0 +1,12 @@
+# Overrides for stdlib RBS signatures that are missing keyword arguments
+
+class ::File
+  # Override: Ruby's File.new accepts keyword args like binmode:
+  def initialize: (string | _ToPath | int file_name, ?string | int mode, ?int perm, **untyped) -> void
+end
+
+class ::Pathname
+  # Override: Ruby's Pathname#open accepts keyword args like binmode:
+  def open: (?string | int mode, ?int perm, **untyped) -> ::File
+          | [T] (?string | int mode, ?int perm, **untyped) { (::File) -> T } -> T
+end

sig/http/form_data.rbs

@@ -0,0 +1,30 @@
+# Type signatures for the http-form_data gem
+
+module HTTP
+  module FormData
+    CRLF: String
+
+    class Error < StandardError
+    end
+
+    type formdata = Multipart | Urlencoded
+
+    # Selects encoder type based on given data
+    def self.create: (untyped data, ?encoder: _Encoder?) -> formdata
+
+    # Coerces obj to Hash
+    def self.ensure_hash: (untyped obj) -> Hash[untyped, untyped]
+
+    # Coerces obj to an Enumerable of key-value pairs
+    def self.ensure_data: (untyped obj) -> untyped
+
+    private
+
+    # Checks if data contains multipart data
+    def self.multipart?: (untyped data) -> bool
+
+    interface _Encoder
+      def call: (untyped data) -> String
+    end
+  end
+end

sig/http/form_data/composite_io.rbs

@@ -0,0 +1,32 @@
+module HTTP
+  module FormData
+    class CompositeIO
+      @index: Integer
+      @ios: Array[untyped]
+      @size: Integer?
+
+      # Creates a new CompositeIO from an array of IO-like objects
+      def initialize: (Array[untyped] ios) -> void
+
+      # Reads and returns content across multiple IO objects
+      def read: (?Integer? length, ?String? outbuf) -> String?
+
+      # Returns sum of all IO sizes
+      def size: () -> Integer
+
+      # Rewinds all IO objects and resets cursor
+      def rewind: () -> void
+
+      private
+
+      # Yields chunks with total length up to `length`
+      def read_chunks: (Integer? length) { (String chunk) -> void } -> void
+
+      # Reads chunk from current IO with length up to `max_length`
+      def readpartial: (Integer? max_length) -> String?
+
+      # Advances cursor to the next IO object
+      def advance_io: () -> void
+    end
+  end
+end