Update Enumerable#inject to raise a LocalJumpError if no block or symbol are given

Author: bjfish

CHANGELOG.md

@@ -44,6 +44,7 @@ Compatibility:
 * Update `String#split` to raise `TypeError` when false is given (#2606, @bjfish).
 * Update `String#lstrip!` to remove leading null characters (#2607, @bjfish).
 * Update `File.utime` to return the number of file names in the arguments (#2616, @bjfish).
+* Update `Enumerable#inject` to raise a `LocalJumpError` if no block or symbol are given (#2626, @bjfish).
 
 Performance:
 

spec/ruby/core/enumerable/shared/inject.rb

@@ -66,4 +66,11 @@
   it "returns nil when fails(legacy rubycon)" do
     EnumerableSpecs::EachDefiner.new().send(@method) {|acc,x| 999 }.should == nil
   end
+
+  ruby_bug '#18635', ''...'3.2' do
+    it "raises an ArgumentError when no parameters or block is given" do
+      -> { [1,2].send(@method) }.should raise_error(ArgumentError)
+      -> { {one: 1, two: 2}.send(@method) }.should raise_error(ArgumentError)
+    end
+  end
 end

src/main/java/org/truffleruby/core/array/ArrayNodes.java

@@ -1452,6 +1452,12 @@ protected Object injectSymbolNoInitial(
                     loopProfile);
         }
 
+        @Specialization
+        protected Object injectNoSymbolNonEmptyArrayNoInitial(
+                RubyArray array, NotProvided initialOrSymbol, NotProvided symbol, Nil block) {
+            throw new RaiseException(getContext(), coreExceptions().argumentError("no block or symbol given", this));
+        }
+
         public Object injectSymbolHelper(VirtualFrame frame, RubyArray array, String symbol,
                 ArrayStoreLibrary stores, Object store, Object initial, int start,
                 IntValueProfile arraySizeProfile, LoopConditionProfile loopProfile) {

src/main/ruby/truffleruby/core/enumerable.rb

@@ -492,6 +492,7 @@ def inject(initial=undefined, sym=undefined, &block)
 
     if !block_given? or !Primitive.undefined?(sym)
       if Primitive.undefined?(sym)
+        raise ArgumentError, 'no block or symbol given' if Primitive.undefined?(initial)
         sym = initial
         initial = undefined
       end