Merge pull request #82 from sul-dlss/less-confusing-token-refresh

Less confusing token refresh (maybe?)

lib/folio_client.rb

@@ -51,15 +51,15 @@ class << self
     def configure(url:, login_params:, okapi_headers:, timeout: default_timeout)
       instance.config = OpenStruct.new(
         # For the initial token, use a dummy value to avoid hitting any APIs
-        # during configuration, allowing the `TokenWrapper` to handle auto-magic
-        # token refreshing. Why not immediately get a valid token? Our apps
+        # during configuration, allowing `with_token_refresh_when_unauthorized` to handle
+        # auto-magic token refreshing. Why not immediately get a valid token? Our apps
         # commonly invoke client `.configure` methods in the initializer in all
         # application environments, even those that are never expected to
         # connect to production APIs, such as local development machines.
         #
         # NOTE: `nil` and blank string cannot be used as dummy values here as
         # they lead to a malformed request to be sent, which triggers an
-        # exception not rescued by `TokenWrapper`
+        # exception not rescued by `with_token_refresh_when_unauthorized`
         token: "a temporary dummy token to avoid hitting the API before it is needed",
         url: url,
         login_params: login_params,
@@ -83,7 +83,7 @@ def configure(url:, login_params:, okapi_headers:, timeout: default_timeout)
   # @param path [String] the path to the Folio API request
   # @param params [Hash] params to get to the API
   def get(path, params = {})
-    response = TokenWrapper.refresh(config, connection) do
+    response = with_token_refresh_when_unauthorized do
       connection.get(path, params, {"x-okapi-token": config.token})
     end
 
@@ -100,7 +100,7 @@ def get(path, params = {})
   # @param body [Object] body to post to the API as JSON
   def post(path, body = nil, content_type: "application/json")
     req_body = (content_type == "application/json") ? body&.to_json : body
-    response = TokenWrapper.refresh(config, connection) do
+    response = with_token_refresh_when_unauthorized do
       req_headers = {
         "x-okapi-token": config.token,
         "content-type": content_type
@@ -121,7 +121,7 @@ def post(path, body = nil, content_type: "application/json")
   # @param body [Object] body to put to the API as JSON
   def put(path, body = nil, content_type: "application/json")
     req_body = (content_type == "application/json") ? body&.to_json : body
-    response = TokenWrapper.refresh(config, connection) do
+    response = with_token_refresh_when_unauthorized do
       req_headers = {
         "x-okapi-token": config.token,
         "content-type": content_type
@@ -227,4 +227,30 @@ def interface_details(...)
   def default_timeout
     120
   end
+
+  private
+
+  # Wraps API operations to request new access token if expired.
+  # @yieldreturn response [Faraday::Response] the response to inspect
+  #
+  # @note You likely want to make sure you're wrapping a _single_ HTTP request in this
+  # method, because 1) all calls in the block will be retried from the top if there's
+  # an authN failure detected, and 2) only the response returned by the block will be
+  # inspected for authN failure.
+  # Related: consider that the client instance and its token will live across many
+  # invocations of the FolioClient methods once the client is configured by a consuming application,
+  # since this class is a Singleton.  Thus, a token may expire between any two calls (i.e. it
+  # isn't necessary for a set of operations to collectively take longer than the token lifetime for
+  # expiry to fall in the middle of that related set of HTTP calls).
+  def with_token_refresh_when_unauthorized
+    response = yield
+
+    # if unauthorized, token has likely expired. try to get a new token and then retry the same request(s).
+    if response.status == 401
+      config.token = Authenticator.token(config.login_params, connection)
+      response = yield
+    end
+
+    response
+  end
 end

spec/folio_client_spec.rb

@@ -488,7 +488,8 @@
     end
   end
 
-  # Tests the TokenWrapper that requests a new token, with a method that might first encounter the error
+  # Tests that we request a new token and then retry the same HTTP call, if the HTTP call
+  # returns an unauthorized error
   context "when token is expired" do
     let(:inventory) { instance_double(FolioClient::Inventory, fetch_hrid: nil) }
     let(:hrid) { "in56789" }