Adds environment boolean checks (#302)

Amber currently ships with 3 different environments: development, test
and production.

As a developer I would like to sometimes run code conditionally
depending on the environment that the application is.

```crystal
if Amber.env.development?
  # ... code here ...
end

```

This PR addresses the issue by creating a Amber::Env module that
contains 3 module methods:

```crystal
Amber.env.development?
Amber.env.test?
Amber.env.production?
Amber.env.integration?
Amber.env.staging?
Amber.env.sandbox?

Amber.env.in? %w(development test)
Amber.env.in? %i(development test)

Amber.env.is? "test"
Amber.env.is? :test
```

With the changes in this PR a developer should be able to call the
appropriate method to check for the desired environment.

Adds Additional Module methods

`in?` and `is?` methods to check for inclusion of the environments

Uses rails style for Amber environment checks

spec/amber/amber_spec.cr

@@ -6,14 +6,13 @@ struct RoomSocket < Amber::WebSockets::ClientSocket; end
 
 describe Amber::Server do
   describe ".configure" do
-    it "it loads environment settings from test.yml" do
+    it "loads environment settings from test.yml" do
       settings = Amber::Server.settings
 
       settings.name.should eq "amber_test_app"
       settings.port_reuse.should eq true
       settings.redis_url.should eq "#{ENV["REDIS_URL"]? || "redis://localhost:6379"}"
       settings.port.should eq 3000
-      settings.env.should eq "test"
       settings.color.should eq true
       settings.secret_key_base.should eq "mV6kTmG3k1yVFh-fPYpugSn0wbZveDvrvfQuv88DPF8"
       # Sometimes settings get over written by other tests first and this fails
@@ -26,7 +25,7 @@ describe Amber::Server do
       settings.secrets.should eq expected_secrets
     end
 
-    it "allows you to overide enviroment settings" do
+    it "overrides enviroment settings" do
       Amber::Server.configure do |server|
         server.name = "Hello World App"
         server.port = 8080
@@ -45,7 +44,7 @@ describe Amber::Server do
       settings.secret_key_base.should eq "mV6kTmG3k1yVFh-fPYpugSn0wbZveDvrvfQuv88DPF8"
     end
 
-    it "should still retain environment.yml settings that haven't been overwritten" do
+    it "retains environment.yml settings that haven't been overwritten" do
       # NOTE: Any changes to settings here remain for all specs run afterwards.
       # This is a problem.
 

spec/amber/cli/commands/generator_spec.cr

@@ -5,6 +5,8 @@ module Amber::CLI
     describe MainCommand::Generate do
       context "scaffold" do
         it "generates and compile generated app" do
+          ENV["AMBER_ENV"] = "test"
+
           MainCommand.run ["new", TESTING_APP]
           Dir.cd(TESTING_APP)
           MainCommand.run ["generate", "scaffold", "Animal", "name:string"]
@@ -17,7 +19,8 @@ module Amber::CLI
       end
 
       context "controllers" do
-        it "should generate controller with correct verbs and actions" do
+        it "generates controller with correct verbs and actions" do
+          ENV["AMBER_ENV"] = "test"
           MainCommand.run ["new", TESTING_APP]
           Dir.cd(TESTING_APP)
           MainCommand.run ["generate", "controller", "Animal", "add:post", "list:get", "remove:delete"]

spec/amber/server/env_spec.cr

@@ -0,0 +1,59 @@
+require "../../../spec_helper"
+
+describe Amber do
+  {% for env in %w(development staging test sandbox production) %}
+    describe ".{{env.id}}?" do
+      it "returns true when the environment is {{env.id}}" do
+        Amber::Settings.env = {{env}}
+        Amber.env.{{env.id}}?.should be_truthy
+      end
+
+      it "returns false when the environment does not match" do
+        Amber::Settings.env = "invalid environment"
+        Amber.env.{{env.id}}?.should be_falsey
+      end
+    end
+  {% end %}
+
+  describe ".is?" do
+    it "returns true when the environment matches the argument" do
+      Amber::Settings.env = "staging"
+      result = Amber.env.is? :staging
+
+      result.should be_truthy
+    end
+
+    it "returns true when the environment matches the argument" do
+      Amber::Settings.env = "invalid"
+      result = Amber.env.is? :staging
+
+      result.should be_falsey
+    end
+  end
+
+  describe ".in?" do
+    context "when settings environment is in list" do
+      it "returns true" do
+        Amber::Settings.env = "development"
+
+        symbols_result = Amber.env.in? %i(development test production)
+        strings_result = Amber.env.in? %w(development test production)
+
+        symbols_result.should be_truthy
+        strings_result.should be_truthy
+      end
+    end
+
+    context "when settings environment is not in list" do
+      it "returns false" do
+        Amber::Settings.env = "invalid"
+
+        symbols_result = Amber.env.in? %w(development test production)
+        strings_result = Amber.env.in? %w(development test production)
+
+        symbols_result.should be_falsey
+        strings_result.should be_falsey
+      end
+    end
+  end
+end

src/amber.cr

@@ -13,6 +13,7 @@ require "./amber/exceptions/**"
 require "./amber/extensions/**"
 require "./amber/router/**"
 require "./amber/server/settings"
+require "./amber/server/env"
 require "./amber/validations/**"
 require "./amber/websockets/**"
 

src/amber/server/env.cr

@@ -0,0 +1,34 @@
+module Amber
+  def self.env
+    Env.new(Settings.env.not_nil!.downcase)
+  end
+
+  class Env
+    def initialize(@env : String | Symbol)
+    end
+
+    def in?(environment_list : Array(String | Symbol))
+      (environment_list.map &.to_s.downcase).includes? @env
+    end
+
+    def is?(environment : String | Symbol)
+      @env == environment.to_s.downcase
+    end
+
+    def to_s(io)
+      io << @env
+    end
+
+    private def environments
+      (Dir.entries(CONFIG_DIR).map &.downcase.tr(".yml", "") + ENVIRONMENTS).to_set
+    end
+
+    macro method_missing(call)
+      environment = {{call.name.id.stringify.downcase}}
+      if environment.chars.last == '?'
+        environment  = environment.downcase.tr("?", "")
+        (@env == environment)
+      end
+    end
+  end
+end

src/amber/server/settings.cr

@@ -23,7 +23,8 @@ module Amber
     class_property redis_url = ""
     class_property session : Hash(Symbol, Symbol | String | Int32)
 
-    # loads settings from environment yaml
+    # Loads environment yml settings from the current AMBER_ENV environment variable
+    # and defaults to development environment
     {{ run("./environment.cr") }}
   end
 end