Add support for jobs & queueables, migrations

- Create migration directives & migrators
- Modify Cache classes to support array manipulation
- Create Redis unit and RedisCache implementation
- Create Queueable base class and Queue class that uses Cache backend

src/service/Canon.ts

@@ -1,5 +1,6 @@
 import {Canonical} from './Canonical'
 import {Singleton} from '../di'
+import {Maybe} from '../util'
 
 /**
  * Error throw when a duplicate canonical key is registered.
@@ -46,6 +47,17 @@ export class Canon {
         return this.resources[key] as Canonical<T>
     }
 
+    /**
+     * Get a canonical item from a fully-qualified canonical name.
+     * This is just a quality-of-life wrapper around `this.resource(...).get(...)`.
+     * @param key
+     */
+    getFromFullyQualified(key: string): Maybe<any> {
+        const [namespace, ...parts] = key.split('::')
+        const unqualified = parts.join('::')
+        return this.resource(namespace).get(unqualified)
+    }
+
     /**
      * Register a canonical resource.
      * @param {Canonical} unit

src/service/Canonical.ts

@@ -7,6 +7,7 @@ import {Logging} from './Logging'
 import {Inject} from '../di'
 import * as nodePath from 'path'
 import {Unit} from '../lifecycle/Unit'
+import {isCanonicalReceiver} from '../support/CanonicalReceiver'
 
 /**
  * Interface describing a definition of a single canonical item loaded from the app.
@@ -228,7 +229,16 @@ export abstract class Canonical<T> extends Unit {
 
             const definition = await this.buildCanonicalDefinition(entry)
             this.logging.verbose(`Registering canonical ${this.canonicalItem} "${definition.canonicalName}" from ${entry}`)
-            this.loadedItems[definition.canonicalName] = await this.initCanonicalItem(definition)
+            const resolvedItem = await this.initCanonicalItem(definition)
+
+            if ( isCanonicalReceiver(resolvedItem) ) {
+                resolvedItem.setCanonicalResolver(
+                    `${this.canonicalItems}::${definition.canonicalName}`,
+                    definition.canonicalName,
+                )
+            }
+
+            this.loadedItems[definition.canonicalName] = resolvedItem
         }
 
         this.canon.registerCanonical(this)

src/service/Queueables.ts

@@ -0,0 +1,25 @@
+import {CanonicalStatic} from './CanonicalStatic'
+import {Singleton, Instantiable, StaticClass} from '../di'
+import {CanonicalDefinition} from './Canonical'
+import {Queueable} from '../support/queue/Queue'
+
+/**
+ * A canonical unit that resolves Queueable classes from `app/queueables`.
+ */
+@Singleton()
+export class Queueables extends CanonicalStatic<Queueable, Instantiable<Queueable>> {
+    protected appPath = ['queueables']
+
+    protected canonicalItem = 'job'
+
+    protected suffix = '.job.js'
+
+    public async initCanonicalItem(definition: CanonicalDefinition): Promise<StaticClass<Queueable, Instantiable<Queueable>>> {
+        const item = await super.initCanonicalItem(definition)
+        if ( !(item.prototype instanceof Queueable) ) {
+            throw new TypeError(`Invalid middleware definition: ${definition.originalName}. Controllers must extend from @extollo/lib.Queueable.`)
+        }
+
+        return item
+    }
+}