1 files changed, 80 insertions, 0 deletions
diff --git a/spec/ruby/core/string/rstrip_spec.rb b/spec/ruby/core/string/rstrip_spec.rb
new file mode 100644
index 0000000000..1638ea375d
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+++ b/spec/ruby/core/string/rstrip_spec.rb
@@ -0,0 +1,80 @@
+# frozen_string_literal: false
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative 'shared/strip'
+
+describe "String#rstrip" do
+  it_behaves_like :string_strip, :rstrip
+
+  it "returns a copy of self with trailing whitespace removed" do
+    "  hello  ".rstrip.should == "  hello"
+    "  hello world  ".rstrip.should == "  hello world"
+    "  hello world \n\r\t\n\v\r".rstrip.should == "  hello world"
+    "hello".rstrip.should == "hello"
+    "hello\x00".rstrip.should == "hello"
+    "こにちわ ".rstrip.should == "こにちわ"
+  end
+
+  it "works with lazy substrings" do
+    "  hello  "[1...-1].rstrip.should == " hello"
+    "  hello world  "[1...-1].rstrip.should == " hello world"
+    "  hello world \n\r\t\n\v\r"[1...-1].rstrip.should == " hello world"
+    " こにちわ  "[1...-1].rstrip.should == "こにちわ"
+  end
+
+  it "returns a copy of self with all trailing whitespace and NULL bytes removed" do
+    "\x00 \x00hello\x00 \x00".rstrip.should == "\x00 \x00hello"
+  end
+end
+
+describe "String#rstrip!" do
+  it "modifies self in place and returns self" do
+    a = "  hello  "
+    a.rstrip!.should.equal?(a)
+    a.should == "  hello"
+  end
+
+  it "modifies self removing trailing NULL bytes and whitespace" do
+    a = "\x00 \x00hello\x00 \x00"
+    a.rstrip!
+    a.should == "\x00 \x00hello"
+  end
+
+  it "returns nil if no modifications were made" do
+    a = "hello"
+    a.rstrip!.should == nil
+    a.should == "hello"
+  end
+
+  it "makes a string empty if it is only whitespace" do
+    "".rstrip!.should == nil
+    " ".rstrip.should == ""
+    "  ".rstrip.should == ""
+  end
+
+  it "removes trailing NULL bytes and whitespace" do
+    a = "\000 goodbye \000"
+    a.rstrip!
+    a.should == "\000 goodbye"
+  end
+
+  it "raises a FrozenError on a frozen instance that is modified" do
+    -> { "  hello  ".freeze.rstrip! }.should.raise(FrozenError)
+  end
+
+  # see [ruby-core:23666]
+  it "raises a FrozenError on a frozen instance that would not be modified" do
+    -> { "hello".freeze.rstrip! }.should.raise(FrozenError)
+    -> { "".freeze.rstrip!      }.should.raise(FrozenError)
+  end
+
+  it "raises an Encoding::CompatibilityError if the last non-space codepoint is invalid" do
+    s = "abc\xDF".force_encoding(Encoding::UTF_8)
+    s.valid_encoding?.should == false
+    -> { s.rstrip! }.should.raise(Encoding::CompatibilityError)
+
+    s = "abc\xDF   ".force_encoding(Encoding::UTF_8)
+    s.valid_encoding?.should == false
+    -> { s.rstrip! }.should.raise(Encoding::CompatibilityError)
+  end
+end