Introduce error handling policy

lib/postmen.rb

@@ -6,6 +6,7 @@
 require 'forwardable'
 
 require 'postmen/version'
+require 'postmen/errors'
 require 'postmen/types'
 require 'postmen/connection'
 require 'postmen/collection_proxy'
@@ -37,17 +38,6 @@
 class Postmen
   extend Dry::Configurable
 
-  # Generic Exception class, all other exceptions should inherit from this class
-  Error = Class.new(StandardError)
-  # Exception raised if rate limit was exceeded
-  RateLimitExceeded = Class.new(Error)
-  # Exception raised in case of any connection error
-  ConnectionError = Class.new(Error)
-  # Generic exception raised if the API returns an error
-  RequestError = Class.new(Error)
-  # Expcetion raised if resource was not found.
-  ResourceNotFound = Class.new(RequestError)
-
   # @#!attribute [rw] api_key [String] API key taken from the application.
   setting :api_key
 

lib/postmen/connection.rb

@@ -33,11 +33,34 @@ def get(path, options = {})
       # Switch to failover domain & retry the request
       Postmen.failover!
       retry
+    # Handle Rate limits.
+    # Rate limits are being reset every 60 seconds - we're retrying
+    # given request after that.
+    # @see https://docs.postmen.com/ratelimit.html Documentation
     rescue RateLimitExceeded
       @requests += 1
       raise if @requests > MAX_REQUESTS
       sleep(60)
       retry
+    # If the resource was not found, simply re-raise the exception
+    rescue ResourceNotFound
+      raise
+    # Handle request errors.
+    # Our current error handling policy depends on the error type.
+    # If the API returns information, that the request is retriable,
+    # We're waiting 5 seconds, and trying again with exact same request.
+    # To prevent having infinite loops, we're trying maximum 5 times.
+    # In case that we were unable to make successfull request with that 5 tries,
+    # MaximumNumberOfRetriesReachedError is being raised.
+    #
+    # @raise RequestError if the request is not retriable
+    # @raise MaximumNumberOfRetriesReachedError if the API returned error after 5 retries
+    rescue RequestError => error
+      raise unless error.retriable?
+      raise MaximumNumberOfRetriesReachedError, self if @requests > MAX_REQUESTS
+      @requests += 1
+      sleep(5)
+      retry
     end
 
     # Performs a HTTP POST request.

lib/postmen/errors.rb

@@ -0,0 +1,52 @@
+class Postmen
+  # Generic Exception class, all other exceptions should inherit from this class
+  Error = Class.new(StandardError)
+
+  # Generic exception raised if the API returns an error
+  class RequestError < Error
+    extend Forwardable
+
+    def_delegators :@request, :meta
+
+    def initialize(request)
+      @request = request
+    end
+
+    # Indicates whether request is retryable.
+    # @see https://docs.postmen.com/errors.html API Documentation
+    def retryable?
+      meta.fetch(:retryable, false)
+    end
+
+    # Returns details for the request error
+    # @see https://docs.postmen.com/#meta API Documentation
+    def details
+      meta[:details]
+    end
+
+    # Internal API error code
+    # @see https://docs.postmen.com/errors.html List of Error codes
+    def code
+      meta[:code]
+    end
+
+    # Returns human-readable error message
+    # @see https://docs.postmen.com/#meta API Documentation
+    def message
+      meta[:message]
+    end
+
+    private
+
+    attr_reader :request
+  end
+
+  # Exception raised if rate limit was exceeded
+  RateLimitExceeded = Class.new(Error)
+  # Exception raised in case of any connection error
+  ConnectionError = Class.new(Error)
+  # Exception raised if retriable request reached maximum number of attempts.
+  MaximumNumberOfRetriesReachedError = Class.new(Error)
+  # Expcetion raised if resource was not found.
+  ResourceNotFound = Class.new(RequestError)
+end