Merge pull request #1575 from ksss/json-kernel

Add Kernel#`j`, `jj` and `JSON` with stdlib/json

stdlib/json/0/json.rbs

@@ -1164,6 +1164,43 @@ JSON::VERSION_MAJOR: Integer
 
 JSON::VERSION_MINOR: Integer
 
+%a{annotate:rdoc:skip}
+module Kernel
+  private
+
+  # <!--
+  #   rdoc-file=ext/json/lib/json/common.rb
+  #   - j(*objs)
+  # -->
+  # Outputs *objs* to STDOUT as JSON strings in the shortest form, that is in one
+  # line.
+  #
+  def j: (*_ToJson) -> nil
+
+  # <!--
+  #   rdoc-file=ext/json/lib/json/common.rb
+  #   - jj(*objs)
+  # -->
+  # Outputs *objs* to STDOUT as JSON strings in a pretty format, with indentation
+  # and over many lines.
+  #
+  def jj: (*_ToJson) -> nil
+
+  # <!--
+  #   rdoc-file=ext/json/lib/json/common.rb
+  #   - JSON(object, *args)
+  # -->
+  # If *object* is string-like, parse the string and return the parsed result as a
+  # Ruby data structure. Otherwise, generate a JSON text from the Ruby data
+  # structure object and return it.
+  #
+  # The *opts* argument is passed through to generate/parse respectively. See
+  # generate and parse for their documentation.
+  #
+  def JSON: (string source, ?json_options opts) -> untyped
+          | (_ToJson obj, ?json_options opts) -> String
+end
+
 %a{annotate:rdoc:skip}
 class Object
   # Converts this object to a string (calling #to_s), converts

test/stdlib/json/JSONKernel_test.rb

@@ -0,0 +1,36 @@
+require_relative "../test_helper"
+require "json"
+
+class JSONKernelInstanceTest < Test::Unit::TestCase
+  include TypeAssertions
+
+  library "json"
+  testing "::Kernel"
+
+  def silent
+    orig_stdout = $stdout
+    $stdout = StringIO.new
+    yield
+  ensure
+    $stdout = orig_stdout
+  end
+
+  def test_j
+    silent do
+      assert_send_type("(Integer) -> nil", self, :j, 1)
+      assert_send_type("(Array[Integer]) -> nil", self, :j, [1, 2, 3])
+    end
+  end
+
+  def test_jj
+    silent do
+      assert_send_type("(Integer) -> nil", self, :jj, 1)
+      assert_send_type("(Array[Integer]) -> nil", self, :jj, [1, 2, 3])
+    end
+  end
+
+  def test_JSON
+    assert_send_type("(String) -> Hash[String, Integer]", self, :JSON, '{"a": 1}')
+    assert_send_type("(Array[Integer]) -> String", self, :JSON, [1, 2, 3])
+  end
+end