Schema for Expressions

.github/workflows/ci.yml

@@ -50,15 +50,16 @@ jobs:
           mongodb-version: 4.0
       - name: Check out repository code
         uses: actions/checkout@v4
-      - name: Do some action caching
-        uses: actions/cache@v3
         with:
-          path: vendor/bundle
-          key: ${{ runner.os }}-gems-${{ matrix.ruby }}-${{ matrix.rails }}-${{ hashFiles('**/Gemfile.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-gems-${{ matrix.ruby }}-${{ matrix.rails }}-
+          # Install gems/npm packages from GitHub fails without this
+          persist-credentials: false
       - name: Install libpq-dev
         run: sudo apt-get -yqq install libpq-dev
+      - name: Set up Node
+        uses: actions/setup-node@v3
+        with:
+          cache: 'npm'
+      - run: npm clean-install
       - name: Set up Ruby ${{ matrix.ruby }}
         uses: ruby/setup-ruby@v1
         with:

.github/workflows/examples.yml

@@ -51,15 +51,13 @@ jobs:
           mongodb-version: 4.0
       - name: Check out repository code
         uses: actions/checkout@v4
-      - name: Do some action caching
-        uses: actions/cache@v3
-        with:
-          path: vendor/bundle
-          key: ${{ runner.os }}-gems-${{ matrix.ruby }}-${{ matrix.rails }}-${{ hashFiles('**/Gemfile.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-gems-${{ matrix.ruby }}-${{ matrix.rails }}-
       - name: Install libpq-dev
         run: sudo apt-get -yqq install libpq-dev
+      - name: Set up Node
+        uses: actions/setup-node@v3
+        with:
+          cache: 'npm'
+      - run: npm clean-install
       - name: Set up Ruby ${{ matrix.ruby }}
         uses: ruby/setup-ruby@v1
         with:

.gitignore

@@ -21,4 +21,5 @@ log
 .sass-cache
 bin
 .DS_Store
+node_modules
 .tool-versions

Guardfile

@@ -22,6 +22,9 @@ guard 'rspec', rspec_options do
   watch(/shared_adapter_specs\.rb$/) { 'spec' }
   watch('spec/helper.rb') { 'spec' }
 
+  watch(%r{lib/flipper/expressions}) { 'spec/flipper/expressions_schema_spec.rb' }
+  watch(%r{node_modules/@flippercloud.io/expressions}) { 'spec/flipper/expressions_schema_spec.rb' }
+
   # To run all specs on every change... (useful with focus and fit)
   # watch(%r{.*}) { 'spec' }
 end

Rakefile

@@ -7,6 +7,7 @@ require 'flipper/version'
 # gem uninstall flipper flipper-ui flipper-redis
 desc 'Build gem into the pkg directory'
 task :build do
+  sh 'npm clean-install --silent'
   FileUtils.rm_rf('pkg')
   Dir['*.gemspec'].each do |gemspec|
     system "gem build #{gemspec}"

flipper-expressions-schema.gemspec

@@ -0,0 +1,37 @@
+# -*- encoding: utf-8 -*-
+require File.expand_path('../lib/flipper/version', __FILE__)
+require File.expand_path('../lib/flipper/metadata', __FILE__)
+
+Gem::Specification.new do |gem|
+  SCHEMAS_DIR = File.expand_path("node_modules/@flippercloud.io/expressions/schemas", __dir__)
+
+  # Ensure schemas are downloaded when installed as a git dependency.
+  # This will be handled by rake when the gem is built and published.
+  Gem.post_install do
+    unless File.exist?(SCHEMAS_DIR)
+      warn "Getting schemas from @flippercloud.io/expressions..."
+      Dir.chdir(__dir__) { exec "npm install --silent" }
+    end
+  end
+
+  gem.authors       = ['John Nunemaker']
+  gem.email         = '[email protected]'
+  gem.summary       = 'ActiveRecord adapter for Flipper'
+  gem.license       = 'MIT'
+  gem.homepage      = 'https://www.flippercloud.io/docs/expressions'
+
+  gem.files         = [
+    'package.json',
+    'package-lock.json',
+    'lib/flipper-expressions-schema.rb',
+    'lib/flipper/expression/schema.rb',
+    'lib/flipper/version.rb',
+  ] + Dir['node_modules/@flippercloud.io/expressions/schemas/*.json']
+  gem.name          = 'flipper-expressions-schema'
+  gem.require_paths = ['lib']
+  gem.version       = Flipper::VERSION
+  gem.metadata      = Flipper::METADATA
+
+  gem.add_dependency 'flipper', "~> #{Flipper::VERSION}"
+  gem.add_dependency 'json_schemer', '~> 1.0'
+end

flipper.gemspec

@@ -6,7 +6,7 @@ plugin_files = []
 plugin_test_files = []
 
 Dir['flipper-*.gemspec'].map do |gemspec|
-  spec = eval(File.read(gemspec))
+  spec = Bundler.load_gemspec(gemspec)
   plugin_files << spec.files
   plugin_test_files << spec.files
 end

lib/flipper-expressions-schema.rb

@@ -0,0 +1 @@
+require "flipper/expression/schema"

lib/flipper/expression.rb

@@ -10,14 +10,18 @@ def self.build(object)
 
       case object
       when Hash
-        name = object.keys.first
-        args = object.values.first
-        unless name
+        if(object.keys.size != 1)
           raise ArgumentError, "#{object.inspect} cannot be converted into an expression"
         end
 
-        new(name, Array(args).map { |o| build(o) })
-      when String, Numeric, FalseClass, TrueClass
+        name = object.keys.first
+        args = object.values.first
+
+        # Ensure args are an array, but we can't just use Array(args) because it will convert a Hash to Array
+        args = args.is_a?(Hash) ? [args] : Array(args)
+
+        new(name, args.map { |o| build(o) })
+      when String, Numeric, FalseClass, TrueClass, nil
         Expression::Constant.new(object)
       when Symbol
         Expression::Constant.new(object.to_s)
@@ -56,6 +60,10 @@ def value
       }
     end
 
+    def validate
+      Schema.new.validate(value)
+    end
+
     private
 
     def call_with_context?

lib/flipper/expression/constant.rb

@@ -20,6 +20,10 @@ def eql?(other)
         other.is_a?(self.class) && other.value == value
       end
       alias_method :==, :eql?
+
+      def validate
+        Schema.new.validate(value)
+      end
     end
   end
 end

lib/flipper/expression/schema.rb

@@ -0,0 +1,33 @@
+require "json_schemer"
+
+module Flipper
+  class Expression
+    class Schema < JSONSchemer::Schema::Draft7
+      PATH = Pathname.new(File.expand_path("../../../node_modules/@flippercloud.io/expressions", __dir__))
+
+      def self.schemas
+        @schemas ||=
+          Hash[
+            PATH
+              .glob("schemas/*.json")
+              .map { |path| [File.basename(path), JSON.parse(File.read(path))] }
+          ]
+      end
+
+      def self.examples
+        PATH
+          .glob("examples/*.json")
+          .map { |path| [File.basename(path), JSON.parse(File.read(path))] }
+      end
+
+      def initialize(schema = self.class.schemas["schema.json"])
+        super(
+          schema,
+          insert_property_defaults: true,
+          ref_resolver:
+            lambda { |url| self.class.schemas[File.basename(url.path)] }
+        )
+      end
+    end
+  end
+end

lib/flipper/expressions/add.rb

@@ -0,0 +1,9 @@
+module Flipper
+  module Expressions
+    class Add
+      def self.call(left, right)
+        left + right
+      end
+    end
+  end
+end

lib/flipper/expressions/divide.rb

@@ -0,0 +1,9 @@
+module Flipper
+  module Expressions
+    class Divide
+      def self.call(left, right)
+        left / right
+      end
+    end
+  end
+end

lib/flipper/expressions/duration.rb

@@ -11,7 +11,7 @@ class Duration
         "year" => 31_556_952 # length of a gregorian year (365.2425 days)
       }.freeze
 
-      def self.call(scalar, unit = 'second')
+      def self.call(scalar, unit)
         unit = unit.to_s.downcase.chomp("s")
 
         unless scalar.is_a?(Numeric)

lib/flipper/expressions/max.rb

@@ -0,0 +1,11 @@
+require "flipper/expression"
+
+module Flipper
+  module Expressions
+    class Max
+      def self.call(*args)
+        args.max
+      end
+    end
+  end
+end

lib/flipper/expressions/min.rb

@@ -0,0 +1,11 @@
+require "flipper/expression"
+
+module Flipper
+  module Expressions
+    class Min
+      def self.call(*args)
+        args.min
+      end
+    end
+  end
+end

lib/flipper/expressions/multiply.rb

@@ -0,0 +1,9 @@
+module Flipper
+  module Expressions
+    class Multiply
+      def self.call(left, right)
+        left * right
+      end
+    end
+  end
+end

lib/flipper/expressions/percentage.rb

@@ -2,7 +2,7 @@ module Flipper
   module Expressions
     class Percentage
       def self.call(value)
-        value.to_f.clamp(0, 100)
+        value.clamp(0, 100)
       end
     end
   end

lib/flipper/expressions/percentage_of_actors.rb

@@ -5,7 +5,7 @@ class PercentageOfActors
 
       def self.call(text, percentage, context: {})
         prefix = context[:feature_name] || ""
-        Zlib.crc32("#{prefix}#{text}") % (100 * SCALING_FACTOR) < percentage * SCALING_FACTOR
+        Zlib.crc32("#{prefix}#{text}") % (100 * SCALING_FACTOR) < percentage.clamp(0, 100) * SCALING_FACTOR
       end
     end
   end

lib/flipper/expressions/subtract.rb

@@ -0,0 +1,9 @@
+module Flipper
+  module Expressions
+    class Subtract
+      def self.call(left, right)
+        left - right
+      end
+    end
+  end
+end

lib/flipper/expressions/time.rb

@@ -2,7 +2,7 @@ module Flipper
   module Expressions
     class Time
       def self.call(value)
-        ::Time.parse(value)
+        ::Time.iso8601(value)
       end
     end
   end

lib/flipper/gates/expression.rb

@@ -39,7 +39,7 @@ def open?(context)
       end
 
       def protects?(thing)
-        thing.is_a?(Flipper::Expression) || thing.is_a?(Hash)
+        thing.is_a?(Flipper::Expression) || thing.is_a?(Flipper::Expression::Constant) || thing.is_a?(Hash)
       end
 
       def wrap(thing)