1 files changed, 139 insertions, 2 deletions
diff --git a/spec/ruby/core/enumerable/inject_spec.rb b/spec/ruby/core/enumerable/inject_spec.rb
index e1fe216144..10de321395 100644
--- a/spec/ruby/core/enumerable/inject_spec.rb
+++ b/spec/ruby/core/enumerable/inject_spec.rb
@@ -1,7 +1,144 @@
 require_relative '../../spec_helper'
+require_relative '../array/shared/iterable_and_tolerating_size_increasing'
 require_relative 'fixtures/classes'
-require_relative 'shared/inject'
 
 describe "Enumerable#inject" do
-  it_behaves_like :enumerable_inject, :inject
+  it "with argument takes a block with an accumulator (with argument as initial value) and the current element. Value of block becomes new accumulator" do
+    a = []
+    EnumerableSpecs::Numerous.new.inject(0) { |memo, i| a << [memo, i]; i }
+    a.should == [[0, 2], [2, 5], [5, 3], [3, 6], [6, 1], [1, 4]]
+    EnumerableSpecs::EachDefiner.new(true, true, true).inject(nil) {|result, i| i && result}.should == nil
+  end
+
+  it "produces an array of the accumulator and the argument when given a block with a *arg" do
+    a = []
+    [1,2].inject(0) {|*args| a << args; args[0] + args[1]}
+    a.should == [[0, 1], [1, 2]]
+  end
+
+  it "can take two argument" do
+    EnumerableSpecs::Numerous.new(1, 2, 3).inject(10, :-).should == 4
+    EnumerableSpecs::Numerous.new(1, 2, 3).inject(10, "-").should == 4
+
+    [1, 2, 3].inject(10, :-).should == 4
+    [1, 2, 3].inject(10, "-").should == 4
+  end
+
+  it "converts non-Symbol method name argument to String with #to_str if two arguments" do
+    name = Object.new
+    def name.to_str; "-"; end
+
+    EnumerableSpecs::Numerous.new(1, 2, 3).inject(10, name).should == 4
+    [1, 2, 3].inject(10, name).should == 4
+  end
+
+  it "raises TypeError when the second argument is not Symbol or String and it cannot be converted to String if two arguments" do
+    -> { EnumerableSpecs::Numerous.new(1, 2, 3).inject(10, Object.new) }.should.raise(TypeError, /is not a symbol nor a string/)
+    -> { [1, 2, 3].inject(10, Object.new) }.should.raise(TypeError, /is not a symbol nor a string/)
+  end
+
+  it "ignores the block if two arguments" do
+    -> {
+      EnumerableSpecs::Numerous.new(1, 2, 3).inject(10, :-) { raise "we never get here"}.should == 4
+    }.should complain(/#{__FILE__}:#{__LINE__-1}: warning: given block not used/, verbose: true)
+
+    -> {
+      [1, 2, 3].inject(10, :-) { raise "we never get here"}.should == 4
+    }.should complain(/#{__FILE__}:#{__LINE__-1}: warning: given block not used/, verbose: true)
+  end
+
+  it "does not warn when given a Symbol with $VERBOSE true" do
+    -> {
+      [1, 2].inject(0, :+)
+      [1, 2].inject(:+)
+      EnumerableSpecs::Numerous.new(1, 2).inject(0, :+)
+      EnumerableSpecs::Numerous.new(1, 2).inject(:+)
+    }.should_not complain(verbose: true)
+  end
+
+  it "can take a symbol argument" do
+    EnumerableSpecs::Numerous.new(10, 1, 2, 3).inject(:-).should == 4
+    [10, 1, 2, 3].inject(:-).should == 4
+  end
+
+  it "can take a String argument" do
+    EnumerableSpecs::Numerous.new(10, 1, 2, 3).inject("-").should == 4
+    [10, 1, 2, 3].inject("-").should == 4
+  end
+
+  it "converts non-Symbol method name argument to String with #to_str" do
+    name = Object.new
+    def name.to_str; "-"; end
+
+    EnumerableSpecs::Numerous.new(10, 1, 2, 3).inject(name).should == 4
+    [10, 1, 2, 3].inject(name).should == 4
+  end
+
+  it "raises TypeError when passed not Symbol or String method name argument and it cannot be converted to String" do
+    -> { EnumerableSpecs::Numerous.new(10, 1, 2, 3).inject(Object.new) }.should.raise(TypeError, /is not a symbol nor a string/)
+    -> { [10, 1, 2, 3].inject(Object.new) }.should.raise(TypeError, /is not a symbol nor a string/)
+  end
+
+  it "without argument takes a block with an accumulator (with first element as initial value) and the current element. Value of block becomes new accumulator" do
+    a = []
+    EnumerableSpecs::Numerous.new.inject { |memo, i| a << [memo, i]; i }
+    a.should == [[2, 5], [5, 3], [3, 6], [6, 1], [1, 4]]
+  end
+
+  it "gathers whole arrays as elements when each yields multiple" do
+    multi = EnumerableSpecs::YieldsMulti.new
+    multi.inject([]) {|acc, e| acc << e }.should == [[1, 2], [3, 4, 5], [6, 7, 8, 9]]
+  end
+
+  it "with inject arguments(legacy rubycon)" do
+    # with inject argument
+    EnumerableSpecs::EachDefiner.new().inject(1) {|acc,x| 999 }.should == 1
+    EnumerableSpecs::EachDefiner.new(2).inject(1) {|acc,x| 999 }.should ==  999
+    EnumerableSpecs::EachDefiner.new(2).inject(1) {|acc,x| acc }.should == 1
+    EnumerableSpecs::EachDefiner.new(2).inject(1) {|acc,x| x }.should == 2
+
+    EnumerableSpecs::EachDefiner.new(1,2,3,4).inject(100) {|acc,x| acc + x }.should == 110
+    EnumerableSpecs::EachDefiner.new(1,2,3,4).inject(100) {|acc,x| acc * x }.should == 2400
+
+    EnumerableSpecs::EachDefiner.new('a','b','c').inject("z") {|result, i| i+result}.should == "cbaz"
+  end
+
+  it "without inject arguments(legacy rubycon)" do
+    # no inject argument
+    EnumerableSpecs::EachDefiner.new(2).inject {|acc,x| 999 }.should == 2
+    EnumerableSpecs::EachDefiner.new(2).inject {|acc,x| acc }.should == 2
+    EnumerableSpecs::EachDefiner.new(2).inject {|acc,x| x }.should == 2
+
+    EnumerableSpecs::EachDefiner.new(1,2,3,4).inject {|acc,x| acc + x }.should == 10
+    EnumerableSpecs::EachDefiner.new(1,2,3,4).inject {|acc,x| acc * x }.should == 24
+
+    EnumerableSpecs::EachDefiner.new('a','b','c').inject {|result, i| i+result}.should == "cba"
+    EnumerableSpecs::EachDefiner.new(3, 4, 5).inject {|result, i| result*i}.should == 60
+    EnumerableSpecs::EachDefiner.new([1], 2, 'a','b').inject {|r,i| r<<i}.should == [1, 2, 'a', 'b']
+  end
+
+  it "returns nil when fails(legacy rubycon)" do
+    EnumerableSpecs::EachDefiner.new().inject {|acc,x| 999 }.should == nil
+  end
+
+  it "tolerates increasing a collection size during iterating Array" do
+    array = [:a, :b, :c]
+    ScratchPad.record []
+    i = 0
+
+    array.inject(nil) do |_, e|
+      ScratchPad << e
+      array << i if i < 100
+      i += 1
+    end
+
+    actual = ScratchPad.recorded
+    expected = [:a, :b, :c] + (0..99).to_a
+    actual.sort_by(&:to_s).should == expected.sort_by(&:to_s)
+  end
+
+  it "raises an ArgumentError when no parameters or block is given" do
+    -> { [1,2].inject }.should.raise(ArgumentError)
+    -> { {one: 1, two: 2}.inject }.should.raise(ArgumentError)
+  end
 end