[GR-45621] Fix Coverage.supported?

PullRequest: truffleruby/4133

Author: andrykonchin

CHANGELOG.md

@@ -36,6 +36,7 @@ Compatibility:
 * Add `Integer#ceildiv` method (#3039, @simonlevasseur, @nirvdrum).
 * Implement `Class#attached_object` method (#3039, @andrykonchin).
 * Fix `ENV#{clone,dup}` and raise `TypeError` (#3039, @andrykonchin).
+* Fix `Coverage.supported?` and raise `TypeError` if argument is not Symbol (#3039, @andrykonchin).
 
 Performance:
 

lib/truffle/coverage.rb

@@ -11,6 +11,7 @@
 
 module Coverage
   def self.supported?(mode)
+    Truffle::Type.rb_check_type(mode, Symbol)
     mode == :lines
   end