olivergeorge

Problem

Given some function specs we would like to know if there are bugs in a function definition associated with invalid function calls.

Example

(s/fdef foo :args (s/cat :x number? :y number?) :ret string?)
(s/fdef bar :args (s/cat :z coll?) :ret number?)

olivergeorge

So what did re-natal add over the react-native template?

The shorter version is:

• an extra node dependency
• tweak to where the native apps look for their index file
• a clojurescript project
• a configuration file for re-natal

So not a lot of intrusive changes to how react-native works at all.

olivergeorge

Navigating between scenes

React Native lets us render views but doesn't solve the problem of transitioning between scenes.

Navigation concerns include:

• rendering common elements (headers)
• rendering navigation elements (back button)
• keeping track of global history stack
• navigating between scenes

olivergeorge

Storing data in the app

Without a persistent data store our React Native app would lose all state if killed and restarted.

React Native solves this by providing a simple storage system that is global to the app called AsyncStorage.

Tradeoffs

It is recommended that you use an abstraction on top of AsyncStorage like sunnylqm/react-native-storage but for now a few helper functions seem to suffice. Here's an alternative approach.

Effects

olivergeorge

Storing data in the app using react-native-storage

Without a persistent data store our app would lose all state if killed and restarted.

React Native solves this by providing a simple storage system that is global to the app called AsyncStorage. It is recommended that you use an abstraction on top of AsyncStorage so we use sunnylqm/react-native-storage.

tradeoffs

We've introduced a dependency here. It's possible working directly with StorageAsync would have sufficed. See alternative approach.

olivergeorge

I was struggling to compose datomic queries neatly. In the end I googled and found a blogpost which proposed a sane solution.

My motivation was an API endpoint with optional filters. I'd like my query include additional filters based on the args present.

Anyway, here's how my code ended up looking...

And the article: http://grishaev.me/en/datomic-query

olivergeorge

(ns olivergeorge.schema
  "generate datomic schema from simple spec forms"
  (:require [clojure.spec.alpha :as s]))

(s/def ::schema-type
  (s/or :db.type/string #{'string?}
        :db.type/long #{'int? 'pos-int? 'neg-int? 'nat-int?}
        :db.type/boolean #{'boolean?}
        :db.type/float #{'float?}
        :db.type/double #{'double?}

olivergeorge

(ns can-i-spy.dbg
  (:require [clojure.spec.alpha :as s]))

(defonce dbg-meta (atom {}))

#?(:cljs (defonce dbg-data (atom {})))

(defmacro spy
  [k]
  (let [symbols (keys (:locals &env))

olivergeorge

(ns can-i-stub.main
  (:require [cljs.nodejs :as nodejs]
            [cljs.spec.alpha :as s]
            [clojure.spec.test.alpha :as stest]))

(nodejs/enable-util-print!)

(defn add2 [a b] 10.1)

(s/fdef add2 :args (s/cat :a int? :b int?) :ret int?)

olivergeorge

Couple of extracts from lein deps :tree

With

:dependencies [[com.taoensso/encore "2.92.0"]
                 [org.clojure/clojurescript "1.9.946"]]

[com.taoensso/encore "2.92.0"]