jsii-ruby: low-level ruby client for jsii-runtime (#143)

Implement the low-level API for the jsii-ruby runtime client.

This layer starts the jsii-runtime child node.js process and allows
interacting it via the stdin/stdout request/response interface.

Implemented as a leaky abstraction, so there is no need to
implement glue in ruby for each kernel API. Sync overrides are
implemented as well.

Unit test verifies a common scenario, and specifically verifies
synchronous and async virtual overrides.

Added minimal "no op" support for ruby pacmak which simply
emits the tarballs. This is needed for the initial set of tests.

"npm run build" will:

- Generate jsii-calc via pacmak (just tarballs for now)
- "bundle install" gems
- Run "robucop" (ruby linter)
- Run "gem build" which builds the ruby gem
- Runs unit tests

Related to #144

packages/jsii-pacmak/lib/targets/ruby.ts

@@ -0,0 +1,40 @@
+import * as spec from 'jsii-spec';
+import { Generator } from '../generator';
+import { Target, TargetOptions } from '../target';
+
+export default class Ruby extends Target {
+    protected readonly generator = new PackOnly();
+
+    constructor(options: TargetOptions) {
+        super(options);
+    }
+
+    public build(sourceDir: string, outDir: string) {
+        // TODO: "gem build"
+        return this.copyFiles(sourceDir, outDir);
+    }
+}
+
+// ##################
+// # CODE GENERATOR #
+// ##################
+
+class PackOnly extends Generator {
+
+    protected getAssemblyOutputDir(_mod: spec.Assembly) {
+        return '.';
+    }
+
+    protected onBeginInterface(_ifc: spec.InterfaceType) { return; }
+    protected onEndInterface(_ifc: spec.InterfaceType) { return; }
+    protected onInterfaceMethod(_ifc: spec.InterfaceType, _method: spec.Method) { return; }
+    protected onInterfaceMethodOverload(_ifc: spec.InterfaceType, _overload: spec.Method, _originalMethod: spec.Method) { return; }
+    protected onInterfaceProperty(_ifc: spec.InterfaceType, _prop: spec.Property) { return; }
+    protected onProperty(_cls: spec.ClassType, _prop: spec.Property) { return; }
+    protected onStaticProperty(_cls: spec.ClassType, _prop: spec.Property) { return; }
+    protected onUnionProperty(_cls: spec.ClassType, _prop: spec.Property, _union: spec.UnionTypeReference) { return; }
+    protected onMethod(_cls: spec.ClassType, _method: spec.Method) { return; }
+    protected onMethodOverload(_cls: spec.ClassType, _overload: spec.Method, _originalMethod: spec.Method) { return; }
+    protected onStaticMethod(_cls: spec.ClassType, _method: spec.Method) { return; }
+    protected onStaticMethodOverload(_cls: spec.ClassType, _overload: spec.Method, _originalMethod: spec.Method) { return; }
+}

packages/jsii-ruby-runtime/.gitignore

@@ -0,0 +1,3 @@
+project/version.txt
+project/test/jsii-calc
+project/resources

packages/jsii-ruby-runtime/generate.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+set -euo pipefail
+res="./project/resources"
+
+version=$(node -e "console.log(require('./package.json').version)")
+echo "${version}" > project/version.txt
+
+# embed jsii-runtime as a resource
+mkdir -p ${res}
+rsync -av node_modules/jsii-runtime/dist/ ${res}
+
+# generate jsii-calc for ruby
+mkdir -p project/test/jsii-calc
+jsii-pacmak -t ruby -o project/test/jsii-calc --recurse node_modules/jsii-calc

packages/jsii-ruby-runtime/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "jsii-ruby-runtime",
+  "version": "0.5.0-beta",
+  "description": "Ruby client for jsii runtime",
+  "main": "lib/index.js",
+  "types": "lib/index.d.ts",
+  "scripts": {
+    "gen": "/bin/bash generate.sh",
+    "deps": "cd project && bundle install",
+    "lint": "cd project && rubocop",
+    "build": "npm run gen && npm run deps && npm run lint && cd project && gem build *.gemspec",
+    "test": "cd project && ruby test/suite.rb"
+  },
+  "devDependencies": {
+    "@types/node": "^9.6.18",
+    "jsii-calc": "^0.5.0-beta",
+    "jsii-pacmak": "^0.5.0-beta",
+    "jsii-runtime": "^0.5.0-beta",
+    "typescript": "^2.9.2"
+  },
+  "author": {
+    "name": "Amazon Web Services",
+    "url": "https://aws.amazon.com",
+    "email": "aws-jsii@amazon.com"
+  },
+  "license": "Apache-2.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/awslabs/jsii.git"
+  },
+  "homepage": "https://github.com/awslabs/jsii"
+}

packages/jsii-ruby-runtime/project/.rubocop.yml

@@ -0,0 +1,17 @@
+Metrics/LineLength:
+  Max: 200
+
+Metrics/MethodLength:
+  Max: 1000
+
+Layout/IndentHash:
+  EnforcedStyle: consistent
+
+Style/GuardClause:
+  Enabled: false
+
+Style/IfUnlessModifier:
+  Enabled: false
+
+Metrics/AbcSize:
+  Enabled: false

packages/jsii-ruby-runtime/project/Gemfile

@@ -0,0 +1,3 @@
+source 'https://rubygems.org'
+
+gem 'rubocop', require: false

packages/jsii-ruby-runtime/project/Gemfile.lock

@@ -0,0 +1,29 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    ast (2.4.0)
+    jaro_winkler (1.5.1)
+    parallel (1.12.1)
+    parser (2.5.1.2)
+      ast (~> 2.4.0)
+    powerpack (0.1.2)
+    rainbow (3.0.0)
+    rubocop (0.58.2)
+      jaro_winkler (~> 1.5.1)
+      parallel (~> 1.10)
+      parser (>= 2.5, != 2.5.1.1)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.0, >= 1.0.1)
+    ruby-progressbar (1.9.0)
+    unicode-display_width (1.4.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  rubocop
+
+BUNDLED WITH
+   1.16.3

packages/jsii-ruby-runtime/project/jsii_runtime.gemspec

@@ -0,0 +1,14 @@
+require 'json'
+package_json_path = File.join(File.dirname(__FILE__), '..', 'package.json')
+pkg = JSON.parse(File.read(package_json_path))
+
+Gem::Specification.new do |s|
+  s.name = 'jsii_runtime'
+  s.version = pkg['version']
+  s.licenses = pkg['license']
+  s.summary = pkg['description']
+  s.authors = pkg['author']
+  s.files = Dir['lib/**']
+  puts s.files
+  s.require_paths = ['lib']
+end

packages/jsii-ruby-runtime/project/lib/jsii_runtime.rb

@@ -0,0 +1,126 @@
+require 'open3'
+require 'logger'
+require 'json'
+require_relative 'jsii_runtime/errors'
+
+module Aws
+  module Jsii
+    # Represents the jsii-runtime
+    class Runtime
+      def initialize(debug: false)
+        @logger = Logger.new(STDERR)
+
+        @debug = debug
+        @logger.level = debug ? Logger::DEBUG : Logger::INFO
+
+        runtime_js = File.join(File.dirname(__FILE__), '..', 'resources', 'jsii-runtime.js')
+        @logger.debug("jsii-runtime at: #{runtime_js}")
+        env = {}
+        env['JSII_DEBUG'] = '1' if @debug
+        @stdin, @stdout, wait_thr = Open3.popen2(env, 'node', runtime_js)
+
+        @logger.debug("jsii-runtime started on pid #{wait_thr.pid}")
+
+        # ensure version compat.
+        handshake
+
+        at_exit { close }
+      end
+
+      def close
+        @logger.debug('closing jsii-runtime child-process streams...')
+        @stdin.close
+        @stdout.close
+      end
+
+      def self.define_api(api)
+        define_method(api) do |**opts|
+          request_response(api: api, **opts)
+        end
+      end
+
+      define_api(:load)
+      define_api(:create)
+      define_api(:del)
+      define_api(:get)
+      define_api(:sget)
+      define_api(:set)
+      define_api(:sset)
+      define_api(:invoke)
+      define_api(:sinvoke)
+      define_api(:begin)
+      define_api(:end)
+      define_api(:callbacks)
+      define_api(:complete)
+      define_api(:naming)
+      define_api(:stats)
+
+      def on_callback(&blk)
+        @callback_handler = blk
+      end
+
+      private
+
+      def request_response(req)
+        req_s = JSON.generate(req.delete_if { |_, v| v.nil? })
+
+        @logger.debug("> #{req_s}")
+        @stdin.puts(req_s)
+
+        resp = read_next_response
+        @logger.debug("< #{JSON.generate(resp)}")
+
+        return process_error(resp) if resp['error']
+        return process_callback(resp) if resp['callback']
+
+        # nil "ok" means undefined result (or void).
+        resp['ok']
+      end
+
+      def read_next_response
+        line = @stdout.readline
+        @logger.debug("line: #{line}")
+        JSON.parse(line)
+      end
+
+      def handshake
+        hello = read_next_response
+        version = hello['hello']
+
+        expected_version = File.read(File.join(File.dirname(__FILE__), '..', 'version.txt')).strip
+        expected_version_string = "jsii-runtime@#{expected_version}"
+
+        if version != expected_version_string
+          raise JsiiError, "Invalid jsii-runtime handshake version '#{version}'. Expected: '#{expected_version_string}'"
+        end
+      end
+
+      def process_error(resp)
+        message = resp['error']
+        stack = resp['stack']
+        message += "\n" + stack unless stack.nil?
+        raise JsiiError, message
+      end
+
+      def process_callback(resp)
+        raise JsiiError, 'no callback handler registered with on_callback' if @callback_handler.nil?
+        callback = resp['callback']
+
+        result = nil
+        err = nil
+
+        begin
+          result = @callback_handler.call(callback)
+        rescue StandardError => e
+          err = e
+        end
+
+        request_response(complete: {
+          cbid: callback['cbid'],
+          err: err,
+          result: result
+        })
+      end
+    end
+  end
+end

packages/jsii-ruby-runtime/project/lib/jsii_runtime/errors.rb

@@ -0,0 +1,6 @@
+module Aws
+  module Jsii
+    class JsiiError < StandardError
+    end
+  end
+end