Merge branch 'dkom' of https://github.com/SAP-samples/cloud-cap-samples into dkom

What's working:
- Address information on OP
- Reading of S/4HANA Addresses
- Translations

packages/bookshop/.prettierrc

@@ -0,0 +1,3 @@
+{
+  "printWidth": 120
+}

packages/bookshop/README.md

@@ -0,0 +1,65 @@
+# Bookshop With Address Data From SAP S/4HANA
+
+This is an extended bookshop with business-partner address data from SAP S/4HANA.
+When the user creates an order and uses the value help of the shipping address,
+a synchronous request to SAP S/4HANA is triggered yielding all possible addresses
+belonging to this business partner. Once an address is selected, its data
+is replicated into a local database. To keep data in sync, an event handler
+is registered which listens to all changes of business partners and updates the 
+local database table.
+
+## Prerequisites
+
+`@sap/cds` >= 1.30
+
+
+## Running With Mocks
+Just execute the following command in the `bookshop` folder.
+```
+cds run --in-memory --with-mocks
+```
+
+
+
+## Running With an S/4HANA Backend
+
+To run your app in non-mock mode you need an SAP S/4HANA Cloud system and connect it to your SAP Cloud Platform. You can use the
+[SAP Cloud Platform Extension Factory](https://help.sap.com/viewer/65de2977205c403bbc107264b8eccf4b/Cloud/en-US/346864df64f24011b49abee07bbd79af.html) to automate parts of this task. You need to enable synchronous APIs as well as events that are sent whenever business partners are changed.
+
+To run the app locally, you need to create a `default-env.json` file in the `bookshop` folder containing the binding information (credentials of Enterprise Messaging as well as the destination to the business-partner service).
+
+Provide the credentials in the `cds.requires` section of the `package.json` file in the `bookshop` folder, e.g.
+
+```json
+  "cds": {
+    "requires": {
+      "API_BUSINESS_PARTNER": {
+        "kind": "odata",
+        "model": "srv/external",
+        "credentials": {
+          "destination": "cap-api098"
+        }
+      },
+      "messaging": {
+        "kind": "enterprise-messaging",
+        "credentials": {
+          "prefix": "sap/S4HANAOD/c098/BO"
+        }
+      }
+    }
+  }
+```
+
+Here, `destination` is the destination of your business-partner service and `prefix` is the prefix
+of the topic of the events.
+
+Then simply run the following command in the `bookshop` folder.
+```
+cds run --in-memory
+```
+
+## User Flow
+After starting the app, go to http://localhost:4004/fiori.html#Shell-home and open the app `Manage Orders` to create an order.
+Use the value help of the shipping address to select an address. Create an order item and save the order.
+Then change the address of your business partner (in the mocked case you can trigger the PATCH request in `req.http` ). Refresh
+the object page of your order and see the change.

packages/bookshop/app/_i18n/i18n.properties

@@ -9,5 +9,14 @@ Name = Name
 AuthorName = Author's Name
 Authors = Authors
 Order = Order
+OrderItems = Order Items
 Orders = Orders
 Price = Price
+shippingAddress = Shipping Address
+cityName = City Name
+houseNumber = House Number
+streetName = Street Name
+postalCode = Postal Code
+country = Country
+AddressID = Address ID
+contact = Contact

packages/bookshop/app/common.cds

@@ -72,3 +72,13 @@ annotate my.Authors with {
 	ID @title:'{i18n>ID}' @UI.HiddenFilter;
 	name @title:'{i18n>AuthorName}';
 }
+
+annotate my.Addresses with {
+	ID @title:'{i18n>AddressID}';
+	contact @title:'{i18n>contact}';
+	@readonly cityName @title:'{i18n>cityName}';
+	@readonly streetName @title:'{i18n>streetName}';
+	@readonly postalCode @title:'{i18n>postalCode}';
+	@readonly country @title:'{i18n>country}';
+	@readonly houseNumber @title:'{i18n>houseNumber}';
+}

packages/bookshop/app/orders/fiori-service.cds

@@ -1,117 +1,243 @@
 using AdminService from '../../srv/admin-service';
 
 annotate AdminService.Books with {
-	price @Common.FieldControl: #ReadOnly;
+    price @Common.FieldControl : #ReadOnly;
 }
+
 ////////////////////////////////////////////////////////////////////////////
 //
 //	Common
 //
 annotate AdminService.OrderItems with {
-	book @(
-		Common: {
-			Text: book.title,
-			FieldControl: #Mandatory
-		},
-		ValueList.entity:'Books',
-	);
-	amount @(
-		Common.FieldControl: #Mandatory
-	);
+    book   @(
+        Common                   : {
+            Text         : book.title,
+            FieldControl : #Mandatory
+        },
+        ValueList.entity : 'Books',
+    );
+    amount @(Common.FieldControl : #Mandatory);
 }
 
+annotate AdminService.Orders with {
+    shippingAddress @(Common : {
+        FieldControl : #Mandatory,
+        ValueList    : {
+            CollectionPath  : 'Addresses',
+            Label           : 'Addresses',
+            SearchSupported : 'true',
+            Parameters      : [
+                {
+                    $Type             : 'Common.ValueListParameterOut',
+                    LocalDataProperty : 'shippingAddress_ID',
+                    ValueListProperty : 'ID'
+                },
+                {
+                    $Type             : 'Common.ValueListParameterOut',
+                    LocalDataProperty : 'shippingAddress_contact',
+                    ValueListProperty : 'contact'
+                },
+                {
+                    $Type             : 'Common.ValueListParameterDisplayOnly',
+                    ValueListProperty : 'postalCode'
+                },
+                {
+                    $Type             : 'Common.ValueListParameterDisplayOnly',
+                    ValueListProperty : 'cityName'
+                },
+                {
+                    $Type             : 'Common.ValueListParameterDisplayOnly',
+                    ValueListProperty : 'country'
+                },
+                {
+                    $Type             : 'Common.ValueListParameterDisplayOnly',
+                    ValueListProperty : 'streetName'
+                },
+                {
+                    $Type             : 'Common.ValueListParameterDisplayOnly',
+                    ValueListProperty : 'houseNumber'
+                },
+            ]
+        },
+    });
+}
 
-annotate AdminService.Orders with @(
-	UI: {
-		////////////////////////////////////////////////////////////////////////////
-		//
-		//	Lists of Orders
-		//
-		SelectionFields: [ createdAt, createdBy ],
-		LineItem: [
-			{Value: createdBy, Label:'Customer'},
-			{Value: createdAt, Label:'Date'}
-		],
-		////////////////////////////////////////////////////////////////////////////
-		//
-		//	Order Details
-		//
-		HeaderInfo: {
-			TypeName: 'Order', TypeNamePlural: 'Orders',
-			Title: {
-				Label: 'Order number ', //A label is possible but it is not considered on the ObjectPage yet
-				Value: OrderNo
-			},
-			Description: {Value: createdBy}
-		},
-		Identification: [ //Is the main field group
-			{Value: createdBy, Label:'Customer'},
-			{Value: createdAt, Label:'Date'},
-			{Value: OrderNo },
-		],
-		HeaderFacets: [
-			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Created}', Target: '@UI.FieldGroup#Created'},
-			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Modified}', Target: '@UI.FieldGroup#Modified'},
-		],
-		Facets: [
-			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Details}', Target: '@UI.FieldGroup#Details'},
-			{$Type: 'UI.ReferenceFacet', Label: '{i18n>OrderItems}', Target: 'Items/@UI.LineItem'},
-		],
-		FieldGroup#Details: {
-			Data: [
-				{Value: currency_code, Label:'Currency'}
-			]
-		},
-		FieldGroup#Created: {
-			Data: [
-				{Value: createdBy},
-				{Value: createdAt},
-			]
-		},
-		FieldGroup#Modified: {
-			Data: [
-				{Value: modifiedBy},
-				{Value: modifiedAt},
-			]
-		},
-	},
+////////////////////////////////////////////////////////////////////////////
+//
+//	UI
+//
+annotate AdminService.Orders with @(UI : {
+    ////////////////////////////////////////////////////////////////////////////
+    //
+    //	Lists of Orders
+    //
+    SelectionFields             : [
+        createdAt,
+        createdBy
+    ],
+    LineItem                    : [
+        {
+            Value : createdBy,
+            Label : 'Customer'
+        },
+        {
+            Value : createdAt,
+            Label : 'Date'
+        }
+    ],
+    ////////////////////////////////////////////////////////////////////////////
+    //
+    //	Order Details
+    //
+    HeaderInfo                  : {
+        TypeName       :          'Order',
+        TypeNamePlural :          'Orders',
+        Title          :          {
+            Label                       : 'Order number ', //A label is possible but it is not considered on the ObjectPage yet
+                                  Value : OrderNo
+        },
+        Description    :          {Value : createdBy}
+    },
+    Identification              : [ //Is the main field group
+                                  // labels not considered
+                                  {
+            Value : createdBy,
+            Label : 'Customer'
+        },
+        {
+            Value : createdAt,
+            Label : 'Date'
+        },
+        {Value    : OrderNo},
+        {
+            Value : 'shippingAddress_ID',
+            Label : 'Address ID'
+        }
+    ],
+    HeaderFacets                : [
+        {
+            $Type  : 'UI.ReferenceFacet',
+            Label  : '{i18n>Created}',
+            Target : '@UI.FieldGroup#Created'
+        },
+        {
+            $Type  : 'UI.ReferenceFacet',
+            Label  : '{i18n>Modified}',
+            Target : '@UI.FieldGroup#Modified'
+        },
+    ],
+    Facets                      : [
+        {
+            $Type  : 'UI.ReferenceFacet',
+            Label  : '{i18n>shippingAddress}',
+            Target : '@UI.FieldGroup#ShippingAddress'
+        },
+        {
+            $Type  : 'UI.ReferenceFacet',
+            Label  : '{i18n>Details}',
+            Target : '@UI.FieldGroup#Details'
+        },
+        {
+            $Type  : 'UI.ReferenceFacet',
+            Label  : '{i18n>OrderItems}',
+            Target : 'Items/@UI.LineItem'
+        },
+    ],
+    FieldGroup #Details         : {Data : [{
+        Value : currency_code,
+        Label : 'Currency'
+    }]},
+    FieldGroup #Created         : {Data : [
+        {Value : createdBy},
+        {Value : createdAt},
+    ]},
+    FieldGroup #Modified        : {Data : [
+        {Value : modifiedBy},
+        {Value : modifiedAt},
+    ]},
+    FieldGroup #ShippingAddress : {Data : [
+        {
+            Value : shippingAddress_ID,
+            Label : '{i18n>shippingAddress}'
+        },
+        {
+            Value : shippingAddress.houseNumber,
+            Label : '{i18n>houseNumber}'
+        },
+        {
+            Value : shippingAddress.streetName,
+            Label : '{i18n>streetName}'
+        },
+        {
+            Value : shippingAddress.cityName,
+            Label : '{i18n>cityName}'
+        },
+        {
+            Value : shippingAddress.postalCode,
+            Label : '{i18n>postalCode}'
+        },
+    ]},
+},
+Common.SideEffects : {
+        EffectTypes      : #ValueChange,
+        SourceProperties : [shippingAddress_ID],
+        TargetProperties : [
+            shippingAddress.country,
+            shippingAddress.houseNumber,
+            shippingAddress.streetName,
+            shippingAddress.cityName,
+            shippingAddress.postalCode
+        ]
+    },
 ) {
-	createdAt @UI.HiddenFilter:false;
-	createdBy @UI.HiddenFilter:false;
+    createdAt @UI.HiddenFilter : false;
+    createdBy @UI.HiddenFilter : false;
 };
 
-
-
 //The enity types name is AdminService.my_bookshop_OrderItems
 //The annotations below are not generated in edmx WHY?
-annotate AdminService.OrderItems with @(
-	UI: {
-		HeaderInfo: {
-			TypeName: 'Order Item', TypeNamePlural: '	',
-			Title: {
-				Value: book.title
-			},
-			Description: {Value: book.descr}
-		},
-		// There is no filterbar for items so the selctionfileds is not needed
-		SelectionFields: [ book_ID ],
-		////////////////////////////////////////////////////////////////////////////
-		//
-		//	Lists of OrderItems
-		//
-		LineItem: [
-			{Value: book_ID, Label:'Book'},
-			//The following entry is only used to have the assoication followed in the read event
-			{Value: book.price, Label:'Book Price'},
-			{Value: amount, Label:'Quantity'},
-		],
-		Identification: [ //Is the main field group
-			//{Value: ID, Label:'ID'}, //A guid shouldn't be on the UI
-			{Value: book_ID, Label:'Book'},
-			{Value: amount, Label:'Amount'},
-		],
-		Facets: [
-			{$Type: 'UI.ReferenceFacet', Label: '{i18n>OrderItems}', Target: '@UI.Identification'},
-		],
-	},
-);
+annotate AdminService.OrderItems with @(UI : {
+    HeaderInfo      : {
+        TypeName       : 'Order Item',
+        TypeNamePlural : '	',
+        Title          : {Value : book.title},
+        Description    : {Value : book.descr}
+    },
+    // There is no filterbar for items so the selctionfileds is not needed
+    SelectionFields : [book_ID],
+    ////////////////////////////////////////////////////////////////////////////
+    //
+    //	Lists of OrderItems
+    //
+    LineItem        : [
+        {
+            Value : book_ID,
+            Label : 'Book'
+        },
+                      //The following entry is only used to have the assoication followed in the read event
+                      {
+            Value : book.price,
+            Label : 'Book Price'
+        },
+        {
+            Value : amount,
+            Label : 'Quantity'
+        },
+    ],
+    Identification  : [ //Is the main field group
+                      //{Value: ID, Label:'ID'}, //A guid shouldn't be on the UI
+                      {
+            Value : book_ID,
+            Label : 'Book'
+        },
+        {
+            Value : amount,
+            Label : 'Amount'
+        },
+    ],
+    Facets          : [{
+        $Type  : 'UI.ReferenceFacet',
+        Label  : '{i18n>OrderItems}',
+        Target : '@UI.Identification'
+    }, ],
+}, );

packages/bookshop/package.json

@@ -5,10 +5,43 @@
   "license": "SAP SAMPLE CODE LICENSE",
   "dependencies": {
     "@sap/cds": "latest",
-    "express": "*"
+    "@sap/xb-msg-amqp-v100": "^0.9.31-SNAPSHOT",
+    "express": "*",
+    "passport": "^0.4.0",
+    "sqlite3": "^4.1.0"
   },
   "scripts": {
     "start": "cds run --in-memory?",
     "watch": "cds watch"
+  },
+  "cds": {
+    "requires": {
+      "API_BUSINESS_PARTNER": {
+        "kind": "odata",
+        "model": "srv/external",
+        "--credentials": {
+          "destination": "cap-api098"
+        }
+      },
+      "--messaging": {
+        "kind": "enterprise-messaging",
+        "credentials": {
+          "prefix": "sap/S4HANAOD/c098/BO"
+        }
+      }
+    },
+    "auth": {
+      "passport": {
+        "strategy": "mock",
+        "users": {
+          "alice": {
+            "roles": [
+              "admin"
+            ],
+            "ID": "ALICE"
+          }
+        }
+      }
+    }
   }
 }

packages/bookshop/req.http

@@ -0,0 +1,19 @@
+PATCH  http://localhost:4004/api-business-partner/A_BusinessPartnerAddress(BusinessPartner='ALICE',AddressID='62640')
+Content-Type: application/json
+Authorization: Basic QUxJQ0Utc2VjcmV0
+
+{
+    "PostalCode": "123456",
+    "CityName": "AlteredTown"
+}
+
+###
+
+GET http://localhost:4004/admin/Orders(ID=7e2f2640-6866-4dcf-8f4d-3027aa831cad,IsActiveEntity=false)?
+&$expand=shippingAddress($select=cityName,houseNumber,postalCode,streetName)
+Authorization: Basic QUxJQ0U6c2VjcmV0
+
+
+###
+
+DELETE  http://localhost:4004/api-business-partner/A_BusinessPartnerAddress(BusinessPartner='ALICE',AddressID='62640')

packages/bookshop/srv/admin-service.cds

@@ -1,6 +1,6 @@
 using { sap.capire.bookshop as my } from '../db/schema';
 
-service AdminService @(_requires:'authenticated-user') {
+service AdminService @(requires:'admin') {
   entity Books as projection on my.Books;
   entity Authors as projection on my.Authors;
   entity Orders as select from my.Orders;

packages/bookshop/srv/admin-service.js

@@ -0,0 +1,77 @@
+const cds = require('@sap/cds')
+module.exports = cds.service.impl(async () => {
+  // We are mashing up three services...
+  const bupa = await cds.connect.to('API_BUSINESS_PARTNER')
+  const admin = await cds.connect.to('AdminService')
+  const db = await cds.connect.to('db')
+
+  // Using reflected definitions from connected services/database
+  const { Addresses: externalAddresses } = bupa.entities // projection on external addresses
+  const { Books, Addresses } = db.entities('sap.capire.bookshop') // entities in local database
+
+  // Delegate ValueHelp requests to S/4 backend, fetching current user's addresses from there
+  admin.on('READ', 'Addresses', req => {
+    console.log('Delegating to S/4 bupa service...')
+    const UsersAddresses = SELECT.from(externalAddresses)
+      .where({ contact: req.user.id })
+      .and(req.query.SELECT.where)
+    return bupa.tx(req).run(UsersAddresses)
+  })
+
+  // Replicate chosen addresses from S/4 when filling orders.
+  admin.before('PATCH', 'Orders', async req => {
+    const assigned = { ID: req.data.shippingAddress_ID, contact: req.user.id }
+    if (!assigned.ID) return //> something else
+    const local = db.transaction(req)
+    const [replica] = await local.read(Addresses).where(assigned)
+    if (replica) return //> already replicated
+    const [address] = await bupa.tx(req).run(SELECT.from(externalAddresses).where(assigned))
+    if (address) return local.create(Addresses).entries(address)
+  })
+
+  // Subscribe to S/4 event to update local replicas when sources change in S/4.
+  bupa.on('BusinessPartner/Changed', async msg => {
+    console.log('>> received:', msg.data)
+
+    const BuPaID = msg.data.KEY[0].BUSINESSPARTNER //> S/4HANA's weird payload format
+    const { SELECT, UPDATE } = cds.ql(msg) //> convenient alternative to <srv>.transaction(req).run(SELECT...)
+
+    // fetch affected entries from local replicas
+    const replicas = await SELECT.from(Addresses).where({ contact: BuPaID })
+    if (replicas.length === 0) return //> not affected
+
+    // fetch changed data from S/4 -> might be less than local due to deletes
+    const changed = await SELECT.from(externalAddresses).where({
+      contact: BuPaID,
+      ID: replicas.map(({ ID }) => ID)
+    })
+
+    // update local replicas with changes from S/4
+    const local = db.transaction(msg) //> using that variant to benefit from bulk runs
+    return local.run(changed.map(a => UPDATE(Addresses, a.ID).with(a)))
+  })
+
+  // Validate incoming orders and reduce books' stocks.
+  admin.before('CREATE', 'Orders', async req => {
+    const { Items } = req.data
+
+    // validate input...
+    if (!Items || Items.length === 0) return req.reject('Please order at least one item.')
+    if (!req.data.shippingAddress_ID) return req.reject('Please enter a valid shipping address.', 'shippingAddress_ID')
+
+    // reduce stock on ordered books...
+    const all = await db.tx(req).run(
+      Items.map(each =>
+        UPDATE(Books)
+          .where('ID =', each.book_ID)
+          .and('stock >=', each.amount)
+          .set('stock -=', each.amount)
+      )
+    )
+    all.forEach(
+      (affectedRows, i) =>
+        affectedRows > 0 || req.error(409, `${Items[i].amount} exceeds stock for book #${Items[i].book_ID}`)
+    )
+  })
+})
+require('./utils')

packages/bookshop/srv/cat-service.js

@@ -2,25 +2,28 @@ const cds = require('@sap/cds')
 const { Books } = cds.entities
 
 /** Service implementation for CatalogService */
-module.exports = cds.service.impl(function() {
-  this.after ('READ', 'Books', each => each.stock > 111 && _addDiscount2(each,11))
-  this.before ('CREATE', 'Orders', _reduceStock)
+module.exports = cds.service.impl(function () {
+  this.after('READ', 'Books', each => each.stock > 111 && _addDiscount2(each, 11))
+  this.before('CREATE', 'Orders', _reduceStock)
 })
 
 /** Add some discount for overstocked books */
-function _addDiscount2 (each,discount) {
+function _addDiscount2 (each, discount) {
   each.title += ` -- ${discount}% discount!`
 }
 
 /** Reduce stock of ordered books if available stock suffices */
 async function _reduceStock (req) {
   const { Items: OrderItems } = req.data
-  return cds.transaction(req) .run (()=> OrderItems.map (order =>
-    UPDATE (Books) .set ('stock -=', order.amount)
-    .where ('ID =', order.book_ID) .and ('stock >=', order.amount)
-  )) .then (all => all.forEach ((affectedRows,i) => {
-    if (affectedRows === 0)  req.error (409,
-      `${OrderItems[i].amount} exceeds stock for book #${OrderItems[i].book_ID}`
+  const all = await cds.transaction(req).run(() =>
+    OrderItems.map(order =>
+      UPDATE(Books)
+        .set('stock -=', order.amount)
+        .where('ID =', order.book_ID)
+        .and('stock >=', order.amount)
     )
-  }))
+  )
+  all.forEach((affectedRows, i) => {
+    if (affectedRows === 0) req.error(409, `${OrderItems[i].amount} exceeds stock for book #${OrderItems[i].book_ID}`)
+  })
 }

packages/bookshop/srv/external.cds

@@ -0,0 +1,39 @@
+using { API_BUSINESS_PARTNER as external } from './external/API_BUSINESS_PARTNER.csn';
+
+/**
+ * Tailor the imported API to our needs...
+ */
+extend service external with {
+
+  /**
+   * Simplified view on external addresses
+   */
+   // @cds.persistence.skip: false
+  @mashup entity Addresses as projection on external.A_BusinessPartnerAddress {
+    key AddressID as ID,
+    key BusinessPartner as contact,
+    Country as country,
+    CityName as cityName,
+    PostalCode as postalCode,
+    StreetName as streetName,
+    HouseNumber as houseNumber
+  }
+}
+
+
+/**
+ * Add an entity to replicate external address data for quick access,
+ * e.g. when displaying lists of orders.
+ */
+@cds.persistence:{table,skip:false} //> create a table with the view's inferred signature
+@cds.autoexpose //> auto-expose in services as targets for ValueHelps and joins
+entity sap.capire.bookshop.Addresses as projection on external.Addresses;
+
+
+/**
+ * Extend Orders with references to replicated external Addresses
+ */
+using { sap.capire.bookshop } from '../db/schema';
+extend bookshop.Orders with {
+  shippingAddress : Association to bookshop.Addresses;
+}

packages/bookshop/srv/external/API_BUSINESS_PARTNER.js

@@ -0,0 +1,11 @@
+module.exports = srv => {
+    srv.on(['CREATE', 'UPDATE', 'DELETE'], req => {
+
+        const payload = {
+            KEY: [{ BUSINESSPARTNER: req.data.BusinessPartner }]
+        }
+        console.log('<< emitting:', payload)
+        srv.emit('BusinessPartner/Changed', payload)
+
+  })
+}

packages/bookshop/srv/external/data/API_BUSINESS_PARTNER-A_BusinessPartnerAddress.csv

@@ -0,0 +1,5 @@
+BusinessPartner;AddressID;CityName;PostalCode;Country;StreetName;HouseNumber
+ALICE;62640;Walldorf;69190;GER;Dietmer-Hopp-Allee;16
+ALICE;62641;Berlin;69390;GER;Berlin-Street;19
+BOB;62341;Karlsruhe;61390;GER;Karlsruhe-Street;19
+anonymous;61321;Sometown;61290;GER;Sometown-Street;19

packages/bookshop/srv/utils.js

@@ -0,0 +1,27 @@
+// Hack for SAP Application Studio
+process.env['http_proxy'] = ''
+process.env['https_proxy'] = ''
+process.env['HTTP_PROXY'] = ''
+process.env['HTTPS_PROXY'] = ''
+
+const diff = (obj1, obj2) =>
+  Object.keys(obj1).reduce((res, curr) => (obj1[curr] === obj2[curr] ? res : (res[curr] = obj2[curr]) && res), {})
+
+const queriesToUpdateDifferences = (entity, ownEntries, otherEntries) =>
+  ownEntries
+    .map(ownEntry => {
+      const otherEntry = otherEntries.find(otherEntry =>
+        Object.keys(entity.keys).reduce((res, curr) => res && otherEntry[curr] === ownEntry[curr], true)
+      )
+      if (otherEntry) {
+        const differences = diff(ownEntry, otherEntry)
+        if (Object.keys(differences).length) {
+          return UPDATE(entity)
+            .set(differences)
+            .where(Object.keys(entity.keys).reduce((res, curr) => (res[curr] = ownEntry[curr]) && res, {}))
+        }
+      }
+    })
+    .filter(el => el)
+
+module.exports = { diff, queriesToUpdateDifferences }