Implement "patch" cli command.

Author: gkellogg

lib/ld/patch.rb

@@ -9,6 +9,7 @@ module LD
   #
   # @author [Gregg Kellogg](http://greggkellogg.net/)
   module Patch
+    require 'ld/patch/format'
     autoload :Algebra,      'ld/patch/algebra'
     autoload :Meta,         'ld/patch/meta'
     autoload :Parser,       'ld/patch/parser'

lib/ld/patch/format.rb

@@ -0,0 +1,53 @@
+module LD::Patch
+  ##
+  # LD::Patch format specification. Note that this format does not define any readers or writers.
+  #
+  # @example Obtaining an LD Patch format class
+  #     RDF::Format.for(:ldp)           #=> LD::Patch::Format
+  #     RDF::Format.for("etc/foaf.ldp")
+  #     RDF::Format.for(:file_name         => "etc/foaf.ldp")
+  #     RDF::Format.for(file_extension: "ldp")
+  #     RDF::Format.for(:content_type   => "text/ldpatch")
+  #
+  # @see http://www.w3.org/TR/ldpatch/
+  class Format < RDF::Format
+    content_type     'text/ldpatch', extension: :ldp
+    content_encoding 'utf-8'
+
+    ##
+    # Hash of CLI commands appropriate for this format
+    # @return [Hash{Symbol => Lambda(Array, Hash)}]
+    def self.cli_commands
+      {
+        patch: {
+          description: "Patch the current graph using a URI Encoded patch file, or a referenced path file/URI",
+          help: "patch [--patch 'patch'] [--patch-file file]",
+          parse: true,
+          lambda: -> (argv, opts) do
+            opts[:patch] ||= RDF::Util::File.open_file(opts[:patch_file]) {|f| f.read}
+            raise ArgumentError, "Patching requires a URI encoded patch or reference to patch resource" unless opts[:patch]
+            $stdout.puts "Patch"
+            patch = LD::Patch.parse(opts[:patch], base_uri: opts.fetch(:patch_file, "http://rubygems.org/gems/ld-patch"))
+            RDF::CLI.repository.query(patch)
+          end,
+          options: [
+            RDF::CLI::Option.new(
+              symbol: :patch,
+              datatype: String,
+              on: ["--patch STRING"],
+              description: "Patch in URI encoded format"
+            ) {|v| URI.decode(v)},
+            RDF::CLI::Option.new(
+              symbol: :patch_file,
+              datatype: String,
+              on: ["--patch-file URI"],
+              description: "URI of patch file"
+            ) {|v| RDF::URI(v)},
+          ]
+        }
+      }
+    end
+
+    def self.to_sym; :ldpatch; end
+  end
+end

spec/format_spec.rb

@@ -0,0 +1,44 @@
+# coding: utf-8
+$:.unshift "."
+require 'spec_helper'
+require 'rdf/spec/format'
+
+describe LD::Patch::Format do
+  it_behaves_like 'an RDF::Format' do
+    let(:format_class) {JSON::LD::Format}
+  end
+
+  describe ".for" do
+    formats = [
+      :ldpatch,
+      "etc/doap.ldp",
+      {file_name:      'etc/doap.ldp'},
+      {file_extension: 'ldp'},
+      {content_type:   'text/ldpatch'},
+    ].each do |arg|
+      it "discovers with #{arg.inspect}" do
+        expect(RDF::Format.for(arg)).to eq described_class
+      end
+    end
+  end
+
+  describe "#to_sym" do
+    specify {expect(described_class.to_sym).to eq :ldpatch}
+  end
+
+  describe ".cli_commands" do
+    require 'rdf/cli'
+    let(:nt) {File.expand_path("../test-files/1triple.nt", __FILE__)}
+    let(:patch) {File.expand_path("../test-files/add-1triple.ldpatch", __FILE__)}
+    let(:patch_enc) {File.read(patch)} # Not encoded, since decode done in option parsing
+
+    describe "#patch" do
+      it "patches from file" do
+        expect {RDF::CLI.exec(["patch", "serialize", nt], patch_file: patch)}.to write.to(:output)
+      end
+      it "patches from argument" do
+        expect {RDF::CLI.exec(["patch", "serialize", nt], patch: patch_enc)}.to write.to(:output)
+      end
+    end
+  end
+end

spec/test-files/1triple.nt

@@ -0,0 +1 @@
+<http://example.org/s1> <http://example.org/p1> <http://example.org/o1> .

spec/test-files/add-1triple.ldpatch

@@ -0,0 +1 @@
+Add { <http://example.org/s2> <http://example.org/p2> <http://example.org/o2> } .