1 files changed, 62 insertions, 0 deletions
diff --git a/spec/ruby/core/env/element_set_spec.rb b/spec/ruby/core/env/element_set_spec.rb
new file mode 100644
index 0000000000..ca5d468009
--- /dev/null
+++ b/spec/ruby/core/env/element_set_spec.rb
@@ -0,0 +1,62 @@
+require_relative '../../spec_helper'
+
+describe "ENV.[]=" do
+  before :each do
+    @saved_foo = ENV["foo"]
+  end
+
+  after :each do
+    ENV["foo"] = @saved_foo
+  end
+
+  it "sets the environment variable to the given value" do
+    ENV["foo"] = "bar"
+    ENV["foo"].should == "bar"
+  end
+
+  it "returns the value" do
+    value = "bar"
+    ENV.send(:[]=, "foo", value).should.equal?(value)
+  end
+
+  it "deletes the environment variable when the value is nil" do
+    ENV["foo"] = "bar"
+    ENV["foo"] = nil
+    ENV.key?("foo").should == false
+  end
+
+  it "coerces the key argument with #to_str" do
+    k = mock("key")
+    k.should_receive(:to_str).and_return("foo")
+    ENV[k] = "bar"
+    ENV["foo"].should == "bar"
+  end
+
+  it "coerces the value argument with #to_str" do
+    v = mock("value")
+    v.should_receive(:to_str).and_return("bar")
+    ENV["foo"] = v
+    ENV["foo"].should == "bar"
+  end
+
+  it "raises TypeError when the key is not coercible to String" do
+    -> { ENV[Object.new] = "bar" }.should.raise(TypeError, "no implicit conversion of Object into String")
+  end
+
+  it "raises TypeError when the value is not coercible to String" do
+    -> { ENV["foo"] = Object.new }.should.raise(TypeError, "no implicit conversion of Object into String")
+  end
+
+  it "raises Errno::EINVAL when the key contains the '=' character" do
+    -> { ENV["foo="] = "bar" }.should.raise(Errno::EINVAL)
+  end
+
+  it "raises Errno::EINVAL when the key is an empty string" do
+    -> { ENV[""] = "bar" }.should.raise(Errno::EINVAL)
+  end
+
+  it "does nothing when the key is not a valid environment variable key and the value is nil" do
+    ENV["foo="] = nil
+    ENV.key?("foo=").should == false
+  end
+end