Update to work on 3.0

.github/workflows/test.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.5', '2.6', '2.7']
+        ruby-version: ['2.5', '2.6', '2.7', '3.0']
 
     steps:
     - uses: actions/checkout@v2

features/regression.feature

@@ -470,32 +470,6 @@ Feature:
     """
 
 
-  # See this issue for the issue we're testing for: https://github.com/JoshCheek/seeing_is_believing/issues/46
-  # See this issue for why we turn it off on 2.4: https://github.com/flori/json/issues/309
-  #
-  # Not going to get too detailed on what it prints, b/c that message seems pretty fragile,
-  # but just generally that it doesn't fkn blow up
-  @not-2.4
-  @not-2.5
-  @not-2.6
-  @not-2.7
-  Scenario: Old JSON bug
-    Given the file "json_and_encodings.rb":
-    """
-    # encoding: utf-8
-    require 'json'
-    JSON.parse JSON.dump("√")
-    """
-    When I run "seeing_is_believing json_and_encodings.rb"
-    Then stderr is empty
-    And the exit status is 1
-    And stdout includes:
-    """
-    require 'json'             # => true
-    JSON.parse JSON.dump("√")
-    """
-
-
   # https://github.com/JoshCheek/seeing_is_believing/wiki/Encodings
   # https://github.com/JoshCheek/seeing_is_believing/issues/109
   Scenario: Assumes utf-8 for files regardless of what Ruby thinks

lib/seeing_is_believing/event_stream/producer.rb

@@ -11,6 +11,7 @@ class Producer
       # Guarding against hostile users (e.g. me) that do ridiculous things like blowing away these constants
       old_w, $-w = $-w, nil # Ruby warns about accessing deprecated constants
       Object.constants.each do |name|
+        next if name == :SortedSet # Removed in 3.0, but apparently the constant still exists, it just explodes if you reference it
         const_set name, Object.const_get(name)
       end
       $-w = old_w