Refactor event bus and queue system; detect cycles in DI realization and make

src/orm/migrations/Migrator.ts

@@ -2,12 +2,12 @@ import {Container, Inject, Injectable} from '../../di'
 import {Awaitable, collect, ErrorWithContext} from '../../util'
 import {Migration} from './Migration'
 import {Migrations} from '../services/Migrations'
-import {EventBus} from '../../event/EventBus'
 import {ApplyingMigrationEvent} from './events/ApplyingMigrationEvent'
 import {AppliedMigrationEvent} from './events/AppliedMigrationEvent'
 import {RollingBackMigrationEvent} from './events/RollingBackMigrationEvent'
 import {RolledBackMigrationEvent} from './events/RolledBackMigrationEvent'
 import {NothingToMigrateError} from './NothingToMigrateError'
+import {Bus} from '../../support/bus'
 
 /**
  * Manages single-run patches/migrations.
@@ -18,7 +18,7 @@ export abstract class Migrator {
     protected readonly migrations!: Migrations
 
     @Inject()
-    protected readonly bus!: EventBus
+    protected readonly bus!: Bus
 
     @Inject('injector')
     protected readonly injector!: Container
@@ -193,31 +193,11 @@ export abstract class Migrator {
      * @protected
      */
     protected async filterAppliedMigrations(identifiers: string[]): Promise<string[]> {
-        return collect(identifiers)
-            .partialMap(identifier => {
-                const migration = this.migrations.get(identifier)
-                if ( migration ) {
-                    return {
-                        identifier,
-                        migration,
-                    }
-                }
-            })
-            .asyncPipe()
-            .tap(coll => {
-                return coll.promiseMap(async group => {
-                    return {
-                        ...group,
-                        has: await this.has(group.migration),
-                    }
-                })
-            })
-            .tap(coll => {
-                return coll.filter(group => !group.has)
-                    .pluck<string>('identifier')
-                    .all()
-            })
-            .resolve()
+        const ids = await collect(identifiers)
+            .toAsync()
+            .filterOut(async id => this.has(this.migrations.getOrFail(id)))
+
+        return ids.all()
     }
 
     /**
@@ -226,31 +206,11 @@ export abstract class Migrator {
      * @protected
      */
     protected async filterPendingMigrations(identifiers: string[]): Promise<string[]> {
-        return collect(identifiers)
-            .partialMap(identifier => {
-                const migration = this.migrations.get(identifier)
-                if ( migration ) {
-                    return {
-                        identifier,
-                        migration,
-                    }
-                }
-            })
-            .asyncPipe()
-            .tap(coll => {
-                return coll.promiseMap(async group => {
-                    return {
-                        ...group,
-                        has: await this.has(group.migration),
-                    }
-                })
-            })
-            .tap(coll => {
-                return coll.filter(group => group.has)
-                    .pluck<string>('identifier')
-                    .all()
-            })
-            .resolve()
+        const ids = await collect(identifiers)
+            .toAsync()
+            .filter(async id => this.has(this.migrations.getOrFail(id)))
+
+        return ids.all()
     }
 
     /**
@@ -260,7 +220,7 @@ export abstract class Migrator {
      */
     protected async applying(migration: Migration): Promise<void> {
         const event = <ApplyingMigrationEvent> this.injector.make(ApplyingMigrationEvent, migration)
-        await this.bus.dispatch(event)
+        await this.bus.push(event)
     }
 
     /**
@@ -270,7 +230,7 @@ export abstract class Migrator {
      */
     protected async applied(migration: Migration): Promise<void> {
         const event = <AppliedMigrationEvent> this.injector.make(AppliedMigrationEvent, migration)
-        await this.bus.dispatch(event)
+        await this.bus.push(event)
     }
 
     /**
@@ -280,7 +240,7 @@ export abstract class Migrator {
      */
     protected async rollingBack(migration: Migration): Promise<void> {
         const event = <RollingBackMigrationEvent> this.injector.make(RollingBackMigrationEvent, migration)
-        await this.bus.dispatch(event)
+        await this.bus.push(event)
     }
 
     /**
@@ -290,6 +250,6 @@ export abstract class Migrator {
      */
     protected async rolledBack(migration: Migration): Promise<void> {
         const event = <RolledBackMigrationEvent> this.injector.make(RolledBackMigrationEvent, migration)
-        await this.bus.dispatch(event)
+        await this.bus.push(event)
     }
 }

src/orm/migrations/events/AppliedMigrationEvent.ts

@@ -5,4 +5,6 @@ import {MigrationEvent} from './MigrationEvent'
  * Event fired after a migration is applied.
  */
 @Injectable()
-export class AppliedMigrationEvent extends MigrationEvent {}
+export class AppliedMigrationEvent extends MigrationEvent {
+    eventName = '@extollo/lib.AppliedMigrationEvent'
+}

src/orm/migrations/events/ApplyingMigrationEvent.ts

@@ -5,4 +5,6 @@ import {MigrationEvent} from './MigrationEvent'
  * Event fired before a migration is applied.
  */
 @Injectable()
-export class ApplyingMigrationEvent extends MigrationEvent {}
+export class ApplyingMigrationEvent extends MigrationEvent {
+    eventName = '@extollo/lib.ApplyingMigrationEvent'
+}

src/orm/migrations/events/MigrationEvent.ts

@@ -1,49 +1,13 @@
-import {Event} from '../../../event/Event'
 import {Migration} from '../Migration'
-import {Inject, Injectable} from '../../../di'
-import {Migrations} from '../../services/Migrations'
-import {ErrorWithContext} from '../../../util'
+import {BaseEvent} from '../../../support/bus'
 
 /**
  * Generic base-class for migration-related events.
  */
-@Injectable()
-export abstract class MigrationEvent extends Event {
-    @Inject()
-    protected readonly migrations!: Migrations
-
-    /** The migration relevant to this event. */
-    private internalMigration: Migration
-
-    /**
-     * Get the relevant migration.
-     */
-    public get migration(): Migration {
-        return this.internalMigration
-    }
-
+export abstract class MigrationEvent extends BaseEvent {
     constructor(
-        migration: Migration,
+        public readonly migration: Migration,
     ) {
         super()
-        this.internalMigration = migration
-    }
-
-    dehydrate(): {identifier: string} {
-        return {
-            identifier: this.migration.identifier,
-        }
-    }
-
-    rehydrate(state: {identifier: string}): void {
-        const migration = this.migrations.get(state.identifier)
-
-        if ( !migration ) {
-            throw new ErrorWithContext(`Unable to find migration with identifier: ${state.identifier}`, {
-                identifier: state.identifier,
-            })
-        }
-
-        this.internalMigration = migration
     }
 }

src/orm/migrations/events/MigrationEventSerializer.ts

@@ -0,0 +1,59 @@
+import {BaseSerializer} from '../../../support/bus'
+import {ObjectSerializer} from '../../../support/bus/serial/decorators'
+import {Injectable, Instantiable} from '../../../di'
+import {Awaitable, ErrorWithContext, JSONState} from '../../../util'
+import {MigrationEvent} from './MigrationEvent'
+import {Migrations} from '../../services/Migrations'
+import {AppliedMigrationEvent} from './AppliedMigrationEvent'
+import {ApplyingMigrationEvent} from './ApplyingMigrationEvent'
+import {RolledBackMigrationEvent} from './RolledBackMigrationEvent'
+import {RollingBackMigrationEvent} from './RollingBackMigrationEvent'
+
+export interface MigrationEventSerialPayload extends JSONState {
+    identifier: string
+    eventType: string
+}
+
+@ObjectSerializer()
+@Injectable()
+export class MigrationEventSerializer extends BaseSerializer<MigrationEvent, MigrationEventSerialPayload> {
+    protected decodeSerial(serial: MigrationEventSerialPayload): Awaitable<MigrationEvent> {
+        const migration = this.make<Migrations>(Migrations).get(serial.identifier)
+        if ( !migration ) {
+            throw new ErrorWithContext(`Invalid serialized migration identifier: ${serial.identifier}`)
+        }
+
+        return (new (this.stringToEvent(serial.eventType))(migration))
+    }
+
+    protected encodeActual(actual: MigrationEvent): Awaitable<MigrationEventSerialPayload> {
+        return {
+            identifier: actual.migration.identifier,
+            eventType: actual.eventName,
+        }
+    }
+
+    protected getName(): string {
+        return '@extollo/lib.MigrationEventSerializer'
+    }
+
+    matchActual(some: MigrationEvent): boolean {
+        return some instanceof MigrationEvent
+    }
+
+    private stringToEvent(name: string): Instantiable<MigrationEvent> {
+        if ( name === '@extollo/lib.AppliedMigrationEvent' ) {
+            return AppliedMigrationEvent
+        } else if ( name === '@extollo/lib.ApplyingMigrationEvent' ) {
+            return ApplyingMigrationEvent
+        } else if ( name === '@extollo/lib.RollingBackMigrationEvent' ) {
+            return RollingBackMigrationEvent
+        } else if ( name === '@extollo/lib.RolledBackMigrationEvent' ) {
+            return RolledBackMigrationEvent
+        }
+
+        throw new ErrorWithContext(`Invalid migration event name: ${name}`, {
+            name,
+        })
+    }
+}

src/orm/migrations/events/RolledBackMigrationEvent.ts

@@ -5,4 +5,6 @@ import {MigrationEvent} from './MigrationEvent'
  * Event fired after a migration has been rolled-back.
  */
 @Injectable()
-export class RolledBackMigrationEvent extends MigrationEvent {}
+export class RolledBackMigrationEvent extends MigrationEvent {
+    eventName = '@extollo/lib.RolledBackMigrationEvent'
+}

src/orm/migrations/events/RollingBackMigrationEvent.ts

@@ -5,4 +5,6 @@ import {MigrationEvent} from './MigrationEvent'
  * Event fired before a migration is rolled back.
  */
 @Injectable()
-export class RollingBackMigrationEvent extends MigrationEvent {}
+export class RollingBackMigrationEvent extends MigrationEvent {
+    eventName = '@extollo/lib.RollingBackMigrationEvent'
+}