piotr-yuxuan / closeable-map

Application state management made simple: a Clojure map that implements java.io.Closeable.

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• closeable-map: State management with a java.io.Closeable Clojure map
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• walter-ci: ✨ GitHub Action-based automation for my personal projects
• ephemeral-server: A small test server to catch http calls you don't mock
• poor-mans-distributed-cache: little poc to use KTable as a distributed cache

closeable-map's Issues

`close-with` doesn't work on Java objects

It uses ::fn meta and as such needs a Clojure object. The implementation should change so that it attach the fn to the map and not the object.

Request for comments: `java.io.{Throwable,Error,Exception}`, `clojure.lang.ExceptionInfo`?

Currently closeable-map tries very hard to swallow everything, and as such uses the apex class java.io.Throwable in order to make completely sure errors truly are silent. This is opinionated. Is it a sane default? Why choose another better default? Perhaps this behaviour could be dynamically tuned according to the user's whishes?

Example:

closeable-map/src/piotr_yuxuan/closeable_map.clj

Line 589 in 0bbba17

(catch Throwable th#

This kind of change would break the API as a matter of course, and would trigger version 1.0.0.

Difference of ancestors between CloseableMap and Clj map

See clj-commons/potemkin#63 for an explanation, if any.

Jar issue

Looks like something is wrong with the uploaded jar.

suggested readme example

here is a suggestion for your TL;DR example

TL;DR example

;; in your project
(require '[piotr-yuxuan/closeable-map :refer [closeable-map]])

(defn start
  "Return a running context with values that can be closed."
  [config]
  (closeable-map
    {;; Kafka producers/consumers are java.io.Closeable
     :producer (kafka-producer config)
     :consumer (kafka-consumer config)

     ;; File streams are java.io.Closeable too
     :outfile (io/output-stream (io/file "/tmp/outfile.txt"))

     ;; some libs return a function which when called stop the server, like:
     :server ^closeable-map/fn (http/start-server (api config) (:server config))}))


;; then you can start/stop the app in the repl with:
(comment
  (def config (load-config))
  (def system (start config))

  ;; stop/close all processes/resources with
  (.close system)
)


;; or use in conjunction with `with-open` like in test file
(with-open [context (start config)]
  (testing "unit test with isolated, repeatable context"
    (is (= :yay/🚀 (some-business/function context)))))

When (.close system) is executed, it will:

• Recursively close all instances of java.io.Closeable and java.lang.AutoCloseable
• Recursively call all stop functions marked with ^:closeable-map/fn
• Skip all Closeable marked with ^:closeable-map/ignore
• If the key :closeable-map/on-close is present, it will be assumed
  as a function which takes one argument (the map itself) and used
  run additional closing logic.

  (closeable-map
    {;; Kafka producers/consumers are java.io.Closeable
     :producer (kafka-producer config)
     :consumer (kafka-consumer config)
  
     ;; this function will be executed before the auto close.
     :closeable-map/on-close (fn [this-map] (flush!))
     }
  )

add the possibility to ignore closing errors during close

It would be good to be able to ignore errors during close at key level or for the whole map, like

(closeable-map
    ^:closeable-map/ignore-errors
    {;; Kafka producers/consumers are java.io.Closeable
     :producer (kafka-producer config)
     :consumer (kafka-consumer config)

     ;; File streams are java.io.Closeable too
     :outfile (io/output-stream (io/file "/tmp/outfile.txt"))

     ;; some libs return a function which when called stop the server, like:
     :server ^closeable-map/fn (http/start-server (api config) (:server config))})

Add usage reference

For example: https://github.com/Flexiana/framework/blob/470547cede16aa1dc5a29793abc5ca14d9d73414/examples/state-events/dev/user.clj#L19