1 files changed, 66 insertions, 0 deletions
diff --git a/spec/ruby/core/thread/fetch_spec.rb b/spec/ruby/core/thread/fetch_spec.rb
new file mode 100644
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+++ b/spec/ruby/core/thread/fetch_spec.rb
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+require_relative '../../spec_helper'
+
+describe 'Thread#fetch' do
+  describe 'with 2 arguments' do
+    it 'returns the value of the fiber-local variable if value has been assigned' do
+      th = Thread.new { Thread.current[:cat] = 'meow' }
+      th.join
+      th.fetch(:cat, true).should == 'meow'
+    end
+
+    it "returns the default value if fiber-local variable hasn't been assigned" do
+      th = Thread.new {}
+      th.join
+      th.fetch(:cat, true).should == true
+    end
+  end
+
+  describe 'with 1 argument' do
+    it 'raises a KeyError when the Thread does not have a fiber-local variable of the same name' do
+      th = Thread.new {}
+      th.join
+      -> { th.fetch(:cat) }.should raise_error(KeyError)
+    end
+
+    it 'returns the value of the fiber-local variable if value has been assigned' do
+      th = Thread.new { Thread.current[:cat] = 'meow' }
+      th.join
+      th.fetch(:cat).should == 'meow'
+    end
+  end
+
+  describe 'with a block' do
+    it 'returns the value of the fiber-local variable if value has been assigned' do
+      th = Thread.new { Thread.current[:cat] = 'meow' }
+      th.join
+      th.fetch(:cat) { true }.should == 'meow'
+    end
+
+    it "returns the block value if fiber-local variable hasn't been assigned" do
+      th = Thread.new {}
+      th.join
+      th.fetch(:cat) { true }.should == true
+    end
+
+    it "does not call the block if value has been assigned" do
+      th = Thread.new { Thread.current[:cat] = 'meow' }
+      th.join
+      var = :not_updated
+      th.fetch(:cat) { var = :updated }.should == 'meow'
+      var.should == :not_updated
+    end
+
+    it "uses the block if a default is given and warns about it" do
+      th = Thread.new {}
+      th.join
+      -> {
+        th.fetch(:cat, false) { true }.should == true
+      }.should complain(/warning: block supersedes default value argument/)
+    end
+  end
+
+  it 'raises an ArgumentError when not passed one or two arguments' do
+    -> { Thread.current.fetch() }.should raise_error(ArgumentError)
+    -> { Thread.current.fetch(1, 2, 3) }.should raise_error(ArgumentError)
+  end
+end