1 files changed, 79 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/replace_spec.rb b/spec/ruby/core/hash/replace_spec.rb
new file mode 100644
index 0000000000..db30145e1a
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+++ b/spec/ruby/core/hash/replace_spec.rb
@@ -0,0 +1,79 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Hash#replace" do
+  it "replaces the contents of self with other" do
+    h = { a: 1, b: 2 }
+    h.replace(c: -1, d: -2).should equal(h)
+    h.should == { c: -1, d: -2 }
+  end
+
+  it "tries to convert the passed argument to a hash using #to_hash" do
+    obj = mock('{1=>2,3=>4}')
+    obj.should_receive(:to_hash).and_return({ 1 => 2, 3 => 4 })
+
+    h = {}
+    h.replace(obj)
+    h.should == { 1 => 2, 3 => 4 }
+  end
+
+  it "calls to_hash on hash subclasses" do
+    h = {}
+    h.replace(HashSpecs::ToHashHash[1 => 2])
+    h.should == { 1 => 2 }
+  end
+
+  it "does not retain the default value" do
+    hash = Hash.new(1)
+    hash.replace(b: 2).default.should be_nil
+  end
+
+  it "transfers the default value of an argument" do
+    hash = Hash.new(1)
+    { a: 1 }.replace(hash).default.should == 1
+  end
+
+  it "does not retain the default_proc" do
+    pr = proc { |h, k| h[k] = [] }
+    hash = Hash.new(&pr)
+    hash.replace(b: 2).default_proc.should be_nil
+  end
+
+  it "transfers the default_proc of an argument" do
+    pr = proc { |h, k| h[k] = [] }
+    hash = Hash.new(&pr)
+    { a: 1 }.replace(hash).default_proc.should == pr
+  end
+
+  it "does not call the default_proc of an argument" do
+    hash_a = Hash.new { |h, k| k * 5 }
+    hash_b = Hash.new(-> { raise "Should not invoke lambda" })
+    hash_a.replace(hash_b)
+    hash_a.default.should == hash_b.default
+  end
+
+  it "transfers compare_by_identity flag of an argument" do
+    h = { a: 1, c: 3 }
+    h2 = { b: 2, d: 4 }.compare_by_identity
+    h.replace(h2)
+    h.compare_by_identity?.should == true
+  end
+
+  it "does not retain compare_by_identity flag" do
+    h = { a: 1, c: 3 }.compare_by_identity
+    h.replace(b: 2, d: 4)
+    h.compare_by_identity?.should == false
+  end
+
+  it "raises a FrozenError if called on a frozen instance that would not be modified" do
+    -> do
+      HashSpecs.frozen_hash.replace(HashSpecs.frozen_hash)
+    end.should raise_error(FrozenError)
+  end
+
+  it "raises a FrozenError if called on a frozen instance that is modified" do
+    -> do
+      HashSpecs.frozen_hash.replace(HashSpecs.empty_frozen_hash)
+    end.should raise_error(FrozenError)
+  end
+end