state-flow.api — nubank/state-flow 5.0.0

defflow clj macro

(defflow name & flows)

(defflow name parameters & flows)

Creates a flow and binds it a Var named by name

flow clj macro

(flow description & flows)

Creates a flow which is a composite of flows.

fmap clj

(fmap f flow)

Creates a flow that returns the application of f to the return of flow

get-state clj

(get-state)

(get-state f & args)

Creates a flow that returns the result of applying f (default identity) to state with any additional args.

ignore-error clj

(ignore-error pair)

No-op error handler that simply ignores the error.

invoke clj

(invoke my-fn)

Creates a flow that invokes a function of no arguments and returns the result. Used to invoke side effects e.g.

(state-flow.core/invoke #(Thread/sleep 1000))

log-and-throw-error! clj

(log-and-throw-error! pair)

Error handler that logs the error and throws an exception to notify the flow has failed.

match? clj macro

(match? expected actual & [{:keys [times-to-try sleep-time] :as params}])

Builds a state-flow step which uses matcher-combinators to make an assertion.

expected can be a literal value or a matcher-combinators matcher actual can be a literal value, a primitive step, or a flow params are optional keyword-style args, supporting:

:times-to-try optional, default 1 :sleep-time optional, millis to wait between tries, default 200

Given (= times-to-try 1), match? will evaluate actual just once.

Given (> times-to-try 1), match? will use state-flow-probe/probe to retry up to :times-to-try times, waiting :sleep-time between each try, and stopping when actual produces a value that matches expected.

NOTE: when (> times-to-try 1), actual must be a step or a flow.

Returns a map (in the left value) with information about the success or failure of the match, the details of which are used internally by state-flow and subject to change.

return clj

(return v)

Creates a flow that returns v. Use this as the last step in a flow that you want to reuse in other flows, in order to clarify the return value, e.g.

(def increment-count (flow "increments :count and returns it" (state/modify update :count inc) [new-count (state/gets :count)] (state-flow/return new-count)))

run clj

(run flow)

(run flow initial-state)

Given an initial-state (default {}), runs a flow and returns a tuple of the result of the last step in the flow and the end state.

run* clj

(run* {:keys [init cleanup runner on-error]
       :or {init (constantly {})
            cleanup identity
            runner run
            on-error log-and-throw-error!}
       :as opts}
      flow)

Runs a flow with specified parameters. Use run unless you need the customizations run* supports.

Supported keys in the first argument are:

init optional, default (constantly {}), function of no arguments that returns the initial state cleanup optional, default identity, function of the final state used to perform cleanup, if necessary runner optional, default run, function of a flow and an initial state which will execute the flow on-error optional, default log-and-throw-error!, function of the final result pair to be invoked when the first value in the pair represents an error

swap-state clj

(swap-state f & args)

Creates a flow that replaces state with the result of applying f to state with any additional args.