feat: Enable recording for known environments

Recording methods are auto-enabled by known environments.
For example, RAILS_ENV and APP_ENV are env vars which indicate
the current environment.

Test case recording is auto-enabled in "test" environments.

Remote and request recording is auto-enabled in "development"
environments.

Recording methods can still be manually enabled or disabled using env
vars. But in most cases, this shouldn't be needed.

Author: kgilpin

lib/appmap.rb

@@ -76,4 +76,4 @@
 
 end.call unless ENV['APPMAP_AUTOREQUIRE'] == 'false'
 
-AppMap.initialize_configuration if ENV['APPMAP'] == 'true' && ENV['APPMAP_INITIALIZE'] != 'false'
+AppMap.initialize_configuration if AppMap.recording_enabled? && ENV['APPMAP_INITIALIZE'] != 'false'

lib/appmap/agent.rb

@@ -9,6 +9,7 @@
 
 # load extension
 require_relative 'appmap'
+require_relative './detect_enabled'
 
 module AppMap
   class << self
@@ -114,5 +115,9 @@ def parameter_schema?
     def explain_queries?
       ENV['APPMAP_EXPLAIN_QUERIES'] == 'true'
     end
+
+    def recording_enabled?(recording_method = nil)
+      DetectEnabled.new(recording_method).enabled?
+    end
   end
 end

lib/appmap/cucumber.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'appmap'
 require 'appmap/util'
 require 'fileutils'
 
@@ -55,7 +56,7 @@ def write_scenario(scenario, appmap)
       end
 
       def enabled?
-        ENV['APPMAP'] == 'true'
+        AppMap.recording_enabled?(:cucumber)
       end
 
       def run

lib/appmap/detect_enabled.rb

@@ -0,0 +1,112 @@
+require_relative './recording_methods'
+
+module AppMap
+  # Detects whether AppMap recording should be enabled. This test can be performed generally, or for
+  # a particular recording method. Recording can be enabled explicitly, for example via APPMAP=true,
+  # or it can be enabled implicitly, by running in a dev or test web application environment. Recording
+  # can also disabled explicitly, using environment variables.
+  class DetectEnabled
+    @@detected_for_method = {}
+
+    class << self
+      def clear_cache
+        @@detected_for_method = {}
+      end
+    end
+
+    def initialize(recording_method)
+      @recording_method = recording_method
+    end
+
+    def enabled?
+      unless @@detected_for_method[@recording_method].nil?
+        return @@detected_for_method[@recording_method]
+      end
+
+      raise "Unrecognized recording method: #{@recording_method}" if @recording_method && !AppMap::RECORDING_METHODS.member?(@recording_method)
+
+      message, enabled, enabled_by_env = detect_enabled
+
+      @@detected_for_method[@recording_method] = enabled
+
+      if @recording_method
+        if enabled
+          warn AppMap::Util.color("AppMap #{@recording_method.nil? ? '' : "#{@recording_method} "}recording is enabled because #{message}", :magenta)
+          # Inform the user that legacy APPMAP=true isn't required any more
+          if enabled_by_env && ENV['APPMAP'] == 'true'
+            warn AppMap::Util.color("Note: Setting envirnoment variable APPMAP=true is no longer necessary to enable #{@recording_method} recording in this environment.", :yellow)
+          end
+        end
+      end
+
+      enabled
+    end
+
+    def detect_enabled
+      detection_functions = %i[globally_disabled? recording_method_disabled? globally_enabled? recording_method_enabled? enabled_by_app_env?]
+
+      message, enabled = []
+      while enabled.nil? && !detection_functions.empty?
+        message, enabled = method(detection_functions.shift).call
+      end
+
+      unless enabled.nil?
+        _, enabled_by_env = enabled_by_app_env?
+        return [ message, enabled, enabled_by_env ]
+      else
+        return [ 'it is not enabled by any configuration or framework', false, false ]
+      end
+    end
+
+    def enabled_by_app_env?
+      env_name, app_env = detect_app_env
+      if %i[rspec minitest].member?(@recording_method)
+        return [ "#{env_name} is '#{app_env}'", true ] if app_env == 'test'
+      end
+
+      if @recording_method.nil?
+        return [ "#{env_name} is '#{app_env}'", true ] if %w[test development].member?(app_env)
+      end
+
+      if %i[remote requests].member?(@recording_method)
+        return [ "#{env_name} is '#{app_env}'", true ] if app_env == 'development'
+      end
+    end
+
+    def detect_app_env
+      if rails_env
+        return [ 'RAILS_ENV', rails_env ]
+      elsif ENV['APP_ENV']
+        return [ 'APP_ENV', ENV['APP_ENV']]
+      end
+    end
+
+    def globally_enabled?
+      [ 'APPMAP=true', true ] if ENV['APPMAP'] == 'true'
+    end
+
+    def globally_disabled?
+      [ 'APPMAP=false', false ] if ENV['APPMAP'] == 'false'
+    end
+
+    def recording_method_disabled?
+      return false unless @recording_method
+
+      env_var = [ 'APPMAP', 'RECORD', @recording_method.upcase ].join('_')
+      [ "#{[ 'APPMAP', 'RECORD', @recording_method.upcase ].join('_')}=false", false ] if ENV[env_var] == 'false'
+    end
+
+    def recording_method_enabled?
+      return false unless @recording_method
+
+      env_var = [ 'APPMAP', 'RECORD', @recording_method.upcase ].join('_')
+      [ "#{[ 'APPMAP', 'RECORD', @recording_method.upcase ].join('_')}=true", true ] if ENV[env_var] == 'true'
+    end
+
+    def rails_env
+      return Rails.env if defined?(Rails)
+      
+      return ENV['RAILS_ENV']
+    end
+  end
+end

lib/appmap/middleware/remote_recording.rb

@@ -82,7 +82,7 @@ def call(env)
         # 0
 
         req = Rack::Request.new(env)
-        return handle_record_request(req) if req.path == '/_appmap/record'
+        return handle_record_request(req) if AppMap.recording_enabled?(:remote) && req.path == '/_appmap/record'
 
         start_time = Time.now
         # Support multi-threaded web server such as Puma by recording each thread
@@ -150,7 +150,7 @@ def html_response?(headers)
       end
 
       def record_all_requests?
-        ENV['APPMAP_RECORD_REQUESTS'] == 'true'
+        AppMap.recording_enabled?(:requests)
       end
 
       def recording?

lib/appmap/minitest.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'appmap'
 require 'appmap/util'
 require 'fileutils'
 require 'active_support'
@@ -125,7 +126,7 @@ def save(name:, class_map:, source_location:, test_status:, exception:, events:)
       end
 
       def enabled?
-        ENV['APPMAP'] == 'true'
+        AppMap.recording_enabled?(:minitest)
       end
 
       def run

lib/appmap/railtie.rb

@@ -4,6 +4,11 @@ module AppMap
   # Railtie connects the AppMap recorder to Rails-specific features.
   class Railtie < ::Rails::Railtie
     initializer 'appmap.remote_recording' do
+      # Indicate early in the log when these methods are enabled.
+      %i[remote requests].each do |recording_method|
+        AppMap.recording_enabled?(recording_method)
+      end
+
       require 'appmap/middleware/remote_recording'
       Rails.application.config.middleware.insert_before \
         ActionDispatch::Executor,
@@ -29,4 +34,4 @@ class Railtie < ::Rails::Railtie
       end
     end
   end
-end if ENV['APPMAP'] == 'true'
+end if AppMap.recording_enabled?

lib/appmap/recording_methods.rb

@@ -0,0 +1,3 @@
+module AppMap
+  RECORDING_METHODS = %i[rspec minitest cucumber remote requests].freeze
+end

lib/appmap/rspec.rb

@@ -1,12 +1,11 @@
 # frozen_string_literal: true
 
+require 'appmap'
 require 'appmap/util'
 require 'set'
 require 'fileutils'
 
 module AppMap
-  # Integration of AppMap with RSpec. When enabled with APPMAP=true, the AppMap tracer will
-  # be activated around each scenario which has the metadata key `:appmap`.
   module RSpec
     APPMAP_OUTPUT_DIR = 'tmp/appmap/rspec'
     LOG = false
@@ -216,7 +215,7 @@ def save(name:, class_map:, source_location:, test_status:, exception:, events:)
       end
 
       def enabled?
-        ENV['APPMAP'] == 'true'
+        AppMap.recording_enabled?(:rspec)
       end
 
       def run
@@ -227,7 +226,6 @@ def run
 end
 
 if AppMap::RSpec.enabled?
-  require 'appmap'
   require 'active_support/inflector/transliterate'
   require 'rspec/core'
   require 'rspec/core/example'

lib/appmap/service/test_command_provider.rb

@@ -16,7 +16,7 @@ def all
               command: {
                 program: 'bundle',
                 args: %w[exec rspec] + integration_test_paths[:rspec].map { |path| "./#{path}" },
-                environment: { APPMAP: 'true', DISABLE_SPRING: 'true' }
+                environment: { }
               }
             }
           end
@@ -30,7 +30,7 @@ def all
               command: {
                 program: 'bundle',
                 args: %w[exec cucumber],
-                environment: { APPMAP: 'true', DISABLE_SPRING: 'true' }
+                environment: { }
               }
             }
           end
@@ -48,7 +48,7 @@ def minitest_commands
                 command: {
                   program: 'bundle',
                   args: %w[exec rails test] + integration_test_paths[:minitest].map { |path| "./#{path}" },
-                  environment: { APPMAP: 'true', DISABLE_SPRING: 'true' }
+                  environment: { }
                 }
               }
             ]
@@ -59,7 +59,7 @@ def minitest_commands
                 command: {
                   program: 'bundle',
                   args: ['exec', 'ruby', "./#{path}"],
-                  environment: { APPMAP: 'true', DISABLE_SPRING: 'true' }
+                  environment: { }
                 }
               }
             end