feat(decorator): defaultValueProvider for @Property()

With a defaultValueProvider you're able to have properties like createdAt without the necessity to set the date by hand.
With this we also dropped the UUID as peerDependency.

BREAKING CHANGE:
`@PartitionKeyUUID()` does no longer exist. Use `@Property({ defaultValueProvider: uuidGeneratorFunction })` instead

package.json

@@ -61,7 +61,6 @@
     "@types/jest": "^24.0.18",
     "@types/lodash": "^4.14.137",
     "@types/node": "8.10.40",
-    "@types/uuid": "^3.4.5",
     "aws-sdk": "^2.401.0",
     "colors": "^1.3.3",
     "coveralls": "^3.0.6",
@@ -82,14 +81,12 @@
     "tsutils": "^3.17.1",
     "typedoc": "0.14.0",
     "typedoc-plugin-external-module-name": "^2.1.0",
-    "typescript": ">=2.9.1",
-    "uuid": "^3.3.2"
+    "typescript": ">=2.9.1"
   },
   "peerDependencies": {
     "aws-sdk": "^2.401.0",
     "lodash": "^4.17.11",
     "reflect-metadata": "^0.1.12",
-    "tslib": "^1.10.0",
-    "uuid": "^3.3.2"
+    "tslib": "^1.10.0"
   }
 }

src/decorator/decorators.spec.ts

@@ -117,7 +117,6 @@ describe('Decorators should add correct metadata', () => {
         expect(prop!.nameDb).toBe('id')
         expect(prop!.key).toBeDefined()
         expect(prop!.key!.type).toBe('HASH')
-        expect(prop!.key!.uuid).toBeFalsy()
         expect(prop!.transient).toBeFalsy()
         expect(prop!.typeInfo).toBeDefined()
         expect(prop!.typeInfo!.type).toBe(String)
@@ -130,7 +129,6 @@ describe('Decorators should add correct metadata', () => {
         expect(prop!.nameDb).toBe('creationDate')
         expect(prop!.key).toBeDefined()
         expect(prop!.key!.type).toBe('RANGE')
-        expect(prop!.key!.uuid).toBeFalsy()
         expect(prop!.transient).toBeFalsy()
         expect(prop!.typeInfo).toBeDefined()
       })

src/decorator/impl/property/property-data.model.ts

@@ -6,8 +6,11 @@ import { MapperForType } from '../../../mapper/for-type/base.mapper'
 /**
  * Option interface for @Property decorator
  */
-export interface PropertyData {
-  // the name of property how it is named in dynamoDB
+export interface PropertyData<T> {
+  /**
+   * the name of property how it is named in dynamoDB
+   */
   name: string
-  mapper: MapperForType<any, any>
+  mapper: MapperForType<T, any>
+  defaultValueProvider: () => T
 }

src/decorator/impl/property/property.decorator.ts

@@ -5,12 +5,13 @@ import { PropertyMetadata } from '../../metadata/property-metadata.model'
 import { initOrUpdateProperty } from './init-or-update-property.function'
 import { PropertyData } from './property-data.model'
 
-export function Property(opts: Partial<PropertyData> = {}): PropertyDecorator {
+export function Property<T>(opts: Partial<PropertyData<T>> = {}): PropertyDecorator {
   return (target: object, propertyKey: string | symbol) => {
     if (typeof propertyKey === 'string') {
       const propertyOptions: Partial<PropertyMetadata<any>> = {
         name: propertyKey,
         nameDb: opts.name || propertyKey,
+        defaultValueProvider: opts.defaultValueProvider,
       }
 
       if ('mapper' in opts && !!opts.mapper) {

src/decorator/impl/public-api.ts

@@ -14,7 +14,6 @@ export * from './index/lsi-sort-key.decorator'
 export * from './index/index-type.enum'
 // key
 export * from './key/partition-key.decorator'
-export * from './key/partition-key-uuid.decorator'
 export * from './key/sort-key.decorator'
 
 // model

src/decorator/metadata/metadata.spec.ts

@@ -6,7 +6,7 @@ import {
   INDEX_ACTIVE_CREATED_AT,
   INDEX_COUNT,
   ModelWithABunchOfIndexes,
-  ModelWithAutogeneratedId,
+  ModelWithDefaultValue,
   ModelWithGSI,
   ModelWithLSI,
   ModelWithoutPartitionKeyModel,
@@ -22,7 +22,7 @@ describe('metadata', () => {
   let metaDataLsi: Metadata<ModelWithLSI>
   let metaDataGsi: Metadata<ModelWithGSI>
   let metaDataIndexes: Metadata<ModelWithABunchOfIndexes>
-  let metaDataUuid: Metadata<ModelWithAutogeneratedId>
+  let metaDataDefaultValue: Metadata<ModelWithDefaultValue>
   let metaDataComplex: Metadata<ComplexModel>
 
   beforeEach(() => {
@@ -32,7 +32,7 @@ describe('metadata', () => {
     metaDataLsi = new Metadata(ModelWithLSI)
     metaDataGsi = new Metadata(ModelWithGSI)
     metaDataIndexes = new Metadata(ModelWithABunchOfIndexes)
-    metaDataUuid = new Metadata(ModelWithAutogeneratedId)
+    metaDataDefaultValue = new Metadata(ModelWithDefaultValue)
     metaDataComplex = new Metadata(ComplexModel)
   })
 
@@ -61,12 +61,13 @@ describe('metadata', () => {
     expect(nestedObjDateMeta).toBeUndefined()
   })
 
-  it('getKeysWithUUID', () => {
-    const uuid = metaDataUuid.getKeysWithUUID()
-    expect(uuid.length).toBe(1)
-    expect(uuid[0].key).toBeDefined()
-    expect(uuid[0].key!.uuid).toBeTruthy()
-    expect(uuid[0].name).toBe('id')
+  it('getPropertiesWithDefaultValueProvider', () => {
+    const props = metaDataDefaultValue.getPropertiesWithDefaultValueProvider()
+    expect(props.length).toBe(1)
+    expect(props[0].key).toBeDefined()
+    expect(props[0].name).toBe('id')
+    expect(props[0].defaultValueProvider).toBeDefined()
+    expect(props[0].defaultValueProvider!()).toBeDefined()
   })
 
   it('getPartitionKey', () => {

src/decorator/metadata/metadata.ts

@@ -70,10 +70,10 @@ export class Metadata<T> {
 
   /**
    *
-   * @returns {Array<PropertyMetadata<any>>} Returns all the properties property the @PartitionKeyUUID decorator is present, returns an empty array by default
+   * @returns {Array<PropertyMetadata<any>>} Returns all the properties a defaultValueProvider, returns an empty array by default
    */
-  getKeysWithUUID(): Array<PropertyMetadata<any>> {
-    return filterBy(this.modelOptions, p => !!(p.key && p.key.uuid), [])
+  getPropertiesWithDefaultValueProvider(): Array<PropertyMetadata<any>> {
+    return filterBy(this.modelOptions, p => !!p.defaultValueProvider, [])
   }
 
   /**

src/decorator/metadata/property-metadata.model.ts

@@ -13,7 +13,6 @@ export interface TypeInfo {
 
 export interface Key {
   type: DynamoDB.KeyType
-  uuid?: boolean
 }
 
 export interface PropertyMetadata<T, R extends Attribute = Attribute> {
@@ -49,6 +48,8 @@ export interface PropertyMetadata<T, R extends Attribute = Attribute> {
 
   // index?: IModelAttributeIndex
   transient?: boolean
+
+  defaultValueProvider?: () => any
 }
 
 /**

src/dynamo/expression/logical-operator/attribute.function.ts

@@ -16,7 +16,7 @@ import {
  * @Model()
  * class Person{
  *
- *   @PartitionKeyUUID()
+ *   @PartitionKey()
  *   id: string
  *   age: number
  * }

src/dynamo/expression/logical-operator/update.function.ts

@@ -15,7 +15,7 @@ import {
  * @Model()
  * class Person {
  *
- *   @PartitionKeyUUID()
+ *   @PartitionKey()
  *   id: string
  *   age: number
  * }

src/mapper/mapper.spec.ts

@@ -14,7 +14,7 @@ import {
   Employee,
   Gift,
   Id,
-  ModelWithAutogeneratedId,
+  ModelWithDefaultValue,
   ModelWithCustomMapperModel,
   ModelWithDateAsHashKey,
   ModelWithDateAsIndexHashKey,
@@ -32,6 +32,8 @@ import {
   SimpleWithRenamedPartitionKeyModel,
   StringType,
   Type,
+  ModelWithCustomMapperAndDefaultValue,
+  MyProp,
 } from '../../test/models'
 import { IdMapper } from '../../test/models/model-with-custom-mapper.model'
 import { ModelWithEmptyValues } from '../../test/models/model-with-empty-values'
@@ -667,15 +669,21 @@ describe('Mapper', () => {
         })
       })
 
-      describe('model with autogenerated id', () => {
-        it('should create an uuid', () => {
-          const toDbVal = toDb(new ModelWithAutogeneratedId(), ModelWithAutogeneratedId)
+      describe('model with autogenerated value for id', () => {
+        it('should create an id', () => {
+          const toDbVal = toDb(new ModelWithDefaultValue(), ModelWithDefaultValue)
           expect(toDbVal.id).toBeDefined()
           expect(keyOf(toDbVal.id)).toBe('S')
-          // https://stackoverflow.com/questions/7905929/how-to-test-valid-uuid-guid
-          expect((<StringAttribute>toDbVal.id).S).toMatch(
-            /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
-          )
+          expect((<StringAttribute>toDbVal.id).S).toMatch(/^generated-id-\d{1,3}$/)
+        })
+      })
+
+      describe('model with default value provider AND custom mapper', () => {
+        it('should create correct value', () => {
+          const toDbVal = toDb(new ModelWithCustomMapperAndDefaultValue(), ModelWithCustomMapperAndDefaultValue)
+          expect(toDbVal.myProp).toBeDefined()
+          expect(keyOf(toDbVal.myProp)).toBe('S')
+          expect((<StringAttribute>toDbVal.myProp).S).toBe(MyProp.default().toString())
         })
       })
 

src/mapper/mapper.ts

@@ -1,7 +1,6 @@
 /**
  * @module mapper
  */
-import { v4 as uuidv4 } from 'uuid'
 import { hasSortKey, Metadata } from '../decorator/metadata/metadata'
 import { metadataForModel } from '../decorator/metadata/metadata-for-model.function'
 import { hasType, Key, PropertyMetadata } from '../decorator/metadata/property-metadata.model'
@@ -42,12 +41,14 @@ export function toDb<T>(item: T, modelConstructor?: ModelConstructor<T>): Attrib
     const metadata: Metadata<T> = metadataForModel(modelConstructor)
 
     /*
-     * initialize possible properties with auto generated uuid
+     * initialize possible properties with default value providers
      */
     if (metadata) {
-      metadata.getKeysWithUUID().forEach(propertyMetadata => {
-        if (!Reflect.get(<any>item, propertyMetadata.name)) {
-          Reflect.set(<any>item, propertyMetadata.name, uuidv4())
+      metadata.getPropertiesWithDefaultValueProvider().forEach(propertyMetadata => {
+        const currentVal = Reflect.get(<any>item, propertyMetadata.name)
+        if (currentVal === undefined || currentVal === null) {
+          // tslint:disable-next-line:no-non-null-assertion
+          Reflect.set(<any>item, propertyMetadata.name, propertyMetadata.defaultValueProvider!())
         }
       })
     }

test/models/index.ts

@@ -1,9 +1,10 @@
 export * from './complex.model'
 export * from './custom-table-name.model'
 export * from './employee.model'
-export * from './model-with-autogenerated-id.model'
+export * from './model-with-default-value.model'
 export * from './model-with-custom-mapper.model'
 export * from './model-with-custom-mapper-for-sort-key.model'
+export * from './model-with-custom-mapper-and-default-value.model'
 export * from './model-with-date.model'
 export * from './model-with-enum.model'
 export * from './model-with-indexes.model'

test/models/model-with-custom-mapper-and-default-value.model.ts

@@ -0,0 +1,40 @@
+// tslint:disable:max-classes-per-file
+import { Model } from '../../src/decorator/impl/model/model.decorator'
+import { Property } from '../../src/decorator/impl/property/property.decorator'
+import { MapperForType } from '../../src/mapper/for-type/base.mapper'
+import { StringAttribute } from '../../src/mapper/type/attribute.type'
+
+export class MyProp {
+  static default() {
+    return new MyProp('default', 'none')
+  }
+
+  static parse(v: string) {
+    const p = v.split('-')
+    return new MyProp(p[0], p[1])
+  }
+
+  static toString(v: MyProp) {
+    return `${v.type}-${v.name}`
+  }
+
+  constructor(public type: string, public name: string) {}
+
+  toString() {
+    return MyProp.toString(this)
+  }
+}
+
+const myPropMapper: MapperForType<MyProp, StringAttribute> = {
+  fromDb: a => MyProp.parse(a.S),
+  toDb: v => ({ S: MyProp.toString(v) }),
+}
+
+@Model()
+export class ModelWithCustomMapperAndDefaultValue {
+  @Property({
+    mapper: myPropMapper,
+    defaultValueProvider: () => MyProp.default(),
+  })
+  myProp: MyProp
+}

test/models/model-with-default-value.model.ts

@@ -0,0 +1,8 @@
+import { Model, PartitionKey, Property } from '../../src/dynamo-easy'
+
+@Model()
+export class ModelWithDefaultValue {
+  @PartitionKey()
+  @Property({ defaultValueProvider: () => `generated-id-${Math.floor(Math.random() * 1000)}` })
+  id: string
+}