1 files changed, 103 insertions, 0 deletions
diff --git a/spec/ruby/optional/capi/digest_spec.rb b/spec/ruby/optional/capi/digest_spec.rb
new file mode 100644
index 0000000000..65c5ecebb1
--- /dev/null
+++ b/spec/ruby/optional/capi/digest_spec.rb
@@ -0,0 +1,103 @@
+require_relative 'spec_helper'
+
+begin
+  require 'fiddle'
+rescue LoadError
+  return
+end
+
+load_extension('digest')
+
+describe "C-API Digest functions" do
+  before :each do
+    @s = CApiDigestSpecs.new
+  end
+
+  describe "rb_digest_make_metadata" do
+    before :each do
+      @metadata = @s.rb_digest_make_metadata
+    end
+
+    it "should store the block length" do
+      @s.block_length(@metadata).should == 40
+    end
+
+    it "should store the digest length" do
+      @s.digest_length(@metadata).should == 20
+    end
+
+    it "should store the context size" do
+      @s.context_size(@metadata).should == 129
+    end
+  end
+
+  describe "digest plugin" do
+    before :each do
+      @s = CApiDigestSpecs.new
+      @digest = Digest::TestDigest.new
+
+      # A pointer to the CTX type defined in the extension for this spec. Digest does not make the context directly
+      # accessible as part of its API. However, to ensure we are properly loading the plugin, it's useful to have
+      # direct access to the context pointer to verify its contents.
+      @context = Fiddle::Pointer.new(@s.context(@digest))
+    end
+
+    it "should report the block length" do
+      @digest.block_length.should == 40
+    end
+
+    it "should report the digest length" do
+      @digest.digest_length.should == 20
+    end
+
+    it "should initialize the context" do
+      # Our test plugin always writes the string "Initialized\n" when its init function is called.
+      verify_context("Initialized\n")
+    end
+
+    it "should update the digest" do
+      @digest.update("hello world")
+
+      # Our test plugin always writes the string "Updated: <data>\n" when its update function is called.
+      current = "Initialized\nUpdated: hello world"
+      verify_context(current)
+
+      @digest << "blah"
+
+      current = "Initialized\nUpdated: hello worldUpdated: blah"
+      verify_context(current)
+    end
+
+    it "should finalize the digest" do
+      @digest.update("")
+
+      finish_string = @digest.instance_eval { finish }
+
+      # We expect the plugin to write out the last `@digest.digest_length` bytes, followed by the string "Finished\n".
+      #
+      finish_string.should == "d\nUpdated: Finished\n"
+      finish_string.encoding.should == Encoding::ASCII_8BIT
+    end
+
+    it "should reset the context" do
+      @digest.update("foo")
+      verify_context("Initialized\nUpdated: foo")
+
+      @digest.reset
+
+      # The context will be recreated as a result of the `reset` so we must fetch the latest context pointer.
+      @context = Fiddle::Pointer.new(@s.context(@digest))
+
+      verify_context("Initialized\n")
+    end
+
+    def verify_context(current_body)
+      # In the CTX type, the length of the current context contents is stored in the first byte.
+      byte_count = @context[0]
+      byte_count.should == current_body.bytesize
+
+      # After the size byte follows a string.
+      @context[1, byte_count].should == current_body
+    end
+  end
+end