1 files changed, 55 insertions, 0 deletions

diff --git a/spec/ruby/core/array/fetch_spec.rb b/spec/ruby/core/array/fetch_spec.rb
new file mode 100644
index 0000000000..ee94cfcbb2
--- /dev/null
+++ b/spec/ruby/core/array/fetch_spec.rb
@@ -0,0 +1,55 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Array#fetch" do
+  it "returns the element at the passed index" do
+    [1, 2, 3].fetch(1).should == 2
+    [nil].fetch(0).should == nil
+  end
+
+  it "counts negative indices backwards from end" do
+    [1, 2, 3, 4].fetch(-1).should == 4
+  end
+
+  it "raises an IndexError if there is no element at index" do
+    -> { [1, 2, 3].fetch(3) }.should.raise(IndexError, "index 3 outside of array bounds: -3...3")
+    -> { [1, 2, 3].fetch(-4) }.should.raise(IndexError, "index -4 outside of array bounds: -3...3")
+    -> { [].fetch(0) }.should.raise(IndexError, "index 0 outside of array bounds: 0...0")
+  end
+
+  it "returns default if there is no element at index if passed a default value" do
+    [1, 2, 3].fetch(5, :not_found).should == :not_found
+    [1, 2, 3].fetch(5, nil).should == nil
+    [1, 2, 3].fetch(-4, :not_found).should == :not_found
+    [nil].fetch(0, :not_found).should == nil
+  end
+
+  it "returns the value of block if there is no element at index if passed a block" do
+    [1, 2, 3].fetch(9) { |i| i * i }.should == 81
+    [1, 2, 3].fetch(-9) { |i| i * i }.should == 81
+  end
+
+  it "passes the original index argument object to the block, not the converted Integer" do
+    o = mock('5')
+    def o.to_int(); 5; end
+
+    [1, 2, 3].fetch(o) { |i| i }.should.equal?(o)
+  end
+
+  it "gives precedence to the default block over the default argument" do
+    -> {
+      @result = [1, 2, 3].fetch(9, :foo) { |i| i * i }
+    }.should complain(/block supersedes default value argument/)
+    @result.should == 81
+  end
+
+  it "tries to convert the passed argument to an Integer using #to_int" do
+    obj = mock('to_int')
+    obj.should_receive(:to_int).and_return(2)
+    ["a", "b", "c"].fetch(obj).should == "c"
+  end
+
+  it "raises a TypeError when the passed argument can't be coerced to Integer" do
+    -> { [].fetch("cat") }.should.raise(TypeError, "no implicit conversion of String into Integer")
+  end
+end