Extollo/lib
2
0
Fork 0
Code Issues 15 Pull Requests Projects Releases 21 Wiki Activity

Fix property injection prototype hoisting bug

Browse Source
This commit is contained in:
Garrett Mills
2022-09-13 22:34:16 -05:00
parent c966904418
commit a173393697
16 changed files with 64 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
src/di/decorator/injection.ts
View File

@@ -2,16 +2,16 @@ import 'reflect-metadata'
import {collect, Collection} from '../../util'
import {logIfDebugging} from '../../util/support/debug'
import {
DEPENDENCY_KEYS_METADATA_KEY,
DEPENDENCY_KEYS_SERVICE_TYPE_KEY,
DependencyKey,
DependencyRequirement,
DEPENDENCY_KEYS_METADATA_KEY,
DEPENDENCY_KEYS_PROPERTY_METADATA_KEY,
isInstantiable,
InjectionType,
DEPENDENCY_KEYS_SERVICE_TYPE_KEY,
isInstantiable,
PropertyDependency,
} from '../types'
import {ContainerBlueprint} from '../ContainerBlueprint'
import {propertyInjectionMetadata} from './propertyInjectionMetadata'
/**
* Get a collection of dependency requirements for the given target object.
@@ -67,6 +67,7 @@ export const Injectable = (): ClassDecorator => {
}
}
/**
* Mark the given class property to be injected by the container.
* If a `key` is specified, that DependencyKey will be injected.
@@ -77,10 +78,27 @@ export const Injectable = (): ClassDecorator => {
*/
export const Inject = (key?: DependencyKey, { debug = false } = {}): PropertyDecorator => {
return (target, property) => {
let propertyMetadata = Reflect.getMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, target?.constructor || target) as Collection<PropertyDependency>
if ( !target?.constructor ) {
logIfDebugging('extollo.di.decoration', '[DEBUG] @Inject(): target has no constructor', target)
throw new Error('Unable to define property injection: target has no constructor. Enable `extollo.di.decoration` logging to debug')
}
const propertyTarget = target.constructor
// let propertyMetadata = Reflect.getMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, propertyTarget) as Collection<PropertyDependency>
// Okay, this is a little fucky. We can't use Reflect's metadata capabilities because we need to write the metadata to
// the constructor, not the `target`. Because Reflect is using the prototype to store data, defining a metadata key on the constructor
// will define it for its parent constructors as well.
// So, if you have class A, class B extends A, and class C extends A, the properties for B and C will be defined on A, causing
// BOTH B and C's properties to be injected on any class extending A.
// To get around this, we instead define a custom property on the constructor itself, then use hasOwnProperty to make sure we're not
// getting the one for the parent class via the prototype chain.
let propertyMetadata = Object.prototype.hasOwnProperty.call(propertyTarget, propertyInjectionMetadata) ?
(propertyTarget as any)[propertyInjectionMetadata] as Collection<PropertyDependency> : undefined
if ( !propertyMetadata ) {
propertyMetadata = new Collection<PropertyDependency>()
Reflect.defineMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, propertyMetadata, target?.constructor || target)
;(propertyTarget as any)[propertyInjectionMetadata] = propertyMetadata
}
const type = Reflect.getMetadata('design:type', target, property)
@@ -103,7 +121,7 @@ export const Inject = (key?: DependencyKey, { debug = false } = {}): PropertyDec
logIfDebugging('extollo.di.decoration', '[DEBUG] @Inject() - key:', key, 'property:', property, 'target:', target, 'target constructor:', target?.constructor, 'type:', type)
Reflect.defineMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, propertyMetadata, target?.constructor || target)
;(propertyTarget as any)[propertyInjectionMetadata] = propertyMetadata
}
}