1 files changed, 8 insertions, 30 deletions
diff --git a/spec/ruby/core/string/unpack/shared/basic.rb b/spec/ruby/core/string/unpack/shared/basic.rb
index f636f4689f..2ee2d6899a 100644
--- a/spec/ruby/core/string/unpack/shared/basic.rb
+++ b/spec/ruby/core/string/unpack/shared/basic.rb
@@ -1,49 +1,27 @@
 describe :string_unpack_basic, shared: true do
   it "ignores whitespace in the format string" do
-    "abc".unpack("a \t\n\v\f\r"+unpack_format).should be_an_instance_of(Array)
+    "abc".unpack("a \t\n\v\f\r"+unpack_format).should.instance_of?(Array)
   end
 
   it "calls #to_str to coerce the directives string" do
     d = mock("unpack directive")
     d.should_receive(:to_str).and_return("a"+unpack_format)
-    "abc".unpack(d).should be_an_instance_of(Array)
+    "abc".unpack(d).should.instance_of?(Array)
   end
 
-  it "raises a TypeError when passed nil" do
-    -> { "abc".unpack(nil) }.should raise_error(TypeError)
-  end
-
-  it "raises a TypeError when passed an Integer" do
-    -> { "abc".unpack(1) }.should raise_error(TypeError)
-  end
-
-  ruby_version_is "3.1" do
-    it "starts unpacking from the given offset" do
-      "abc".unpack("CC", offset: 1).should == [98, 99]
-    end
+  it "raises ArgumentError when a directive is unknown" do
+    -> { "abcdefgh".unpack("a K" + unpack_format) }.should.raise(ArgumentError, "unknown unpack directive 'K' in 'a K#{unpack_format}'")
+    -> { "abcdefgh".unpack("a 0" + unpack_format) }.should.raise(ArgumentError, "unknown unpack directive '0' in 'a 0#{unpack_format}'")
+    -> { "abcdefgh".unpack("a :" + unpack_format) }.should.raise(ArgumentError, "unknown unpack directive ':' in 'a :#{unpack_format}'")
   end
 end
 
 describe :string_unpack_no_platform, shared: true do
   it "raises an ArgumentError when the format modifier is '_'" do
-    -> { "abcdefgh".unpack(unpack_format("_")) }.should raise_error(ArgumentError)
+    -> { "abcdefgh".unpack(unpack_format("_")) }.should.raise(ArgumentError)
   end
 
   it "raises an ArgumentError when the format modifier is '!'" do
-    -> { "abcdefgh".unpack(unpack_format("!")) }.should raise_error(ArgumentError)
-  end
-
-  ruby_version_is "3.1" do
-    it "raises an ArgumentError when the offset is negative" do
-      -> { "a".unpack("C", offset: -1) }.should raise_error(ArgumentError)
-    end
-
-    it "returns nil if the offset is at the end of the string" do
-      "a".unpack("C", offset: 1).should == [nil]
-    end
-
-    it "raises an ArgumentError when the offset is larget than the string" do
-      -> { "a".unpack("C", offset: 2) }.should raise_error(ArgumentError)
-    end
+    -> { "abcdefgh".unpack(unpack_format("!")) }.should.raise(ArgumentError)
   end
 end