feat: nested objects comparison added

Readme.md

@@ -8,23 +8,26 @@ First, define the source and destination data arrays. In this example, we have `
 
 ```ts
 const src = [
-  { id: 1, firstName: "John", lastName: "Doe" },
-  { id: 2, firstName: "Jane", lastName: "Diana" },
-  { id: 4, firstName: "Rid", lastName: "Lomba" },
+  { id: 1, company: 1, firstName: "John", lastName: "Doe", age: null },
+  { id: 1, company: 2, firstName: "John", lastName: "Doe", age: null },
+  { id: 2, company: 1, firstName: "Jane", lastName: "Diana", age: null },
+  { id: 4, company: 1, firstName: "Rid", lastName: "Lomba", age: 25 },
+  { id: 5, company: 1, firstName: "Homa", lastName: "Shiri", age: 30 },
 ];
 const dst = [
-  { id: 1, FullName: "John Doe" },
-  { id: 3, FullName: "Doe Risko" },
-  { id: 4, FullName: "Fids Almo" },
+  { id: 1, company: 1, FullName: "John Doe", bio: { age: null } },
+  { id: 3, company: 1, FullName: "Doe Risko", bio: { age: 30 } },
+  { id: 4, company: 1, FullName: "Fids Almo", bio: { age: 26 } },
+  { id: 5, company: 1, FullName: "Homa Shiri", bio: { age: 30 } },
 ];
 ```
 
 ## Step 2: Define the Keys
 
-Specify the keys that uniquely identify each record in the arrays. In this example, we use the `"id"` property as the key.
+Specify the keys that uniquely identify each record in the arrays. In this example, we use the `"id"` and `"company"` property as the key.
 
 ```ts
-const keys = ["id"];
+const keys = ["id", "company"];
 ```
 
 ## Step 3: Create the Sync Engine
@@ -42,11 +45,12 @@ const engine = new SyncEngine<typeof src, typeof dst>({
       // Async function to map the FullName field
       fn: async (row) => {
         // await some async operation
-        return `${row.firstName} ${row.lastName}`;
+        return Promise.resolve(`${row.firstName} ${row.lastName}`);
       },
     },
-    // Sync function to map the id field
     { fieldName: "id", fn: (row) => row.id },
+    { fieldName: "company", fn: (row) => row.company },
+    { fieldName: "bio", fn: (row) => ({ age: row.age }) }, // Nested field
   ],
   // Optional
   syncFns: {

deno.json

@@ -1,5 +1,5 @@
 {
   "name": "@sostad/sync-engine",
-  "version": "1.2.1",
+  "version": "1.3.0",
   "exports": "./mod.ts"
 }

mod.ts

@@ -126,7 +126,7 @@ export class SyncEngine<
       }
     }
 
-    // Find updated records and log the changes
+    // Find updated records
     for (const srcRecord of mappedData) {
       const srcKey = this.keys.map((key) => srcRecord[key]).join("_");
       const dstRecord = this.dst.find((dstRecord) => {
@@ -143,11 +143,22 @@ export class SyncEngine<
 
         for (const [key, value] of Object.entries(srcRecord)) {
           if (dstRecord[key] !== value) {
-            fields.push({
-              fieldName: key,
-              oldValue: dstRecord[key],
-              newValue: value,
-            });
+            // check if value is an object, use _shallowEqual to compare
+            if (typeof value === "object") {
+              if (!this._shallowEqual(value, dstRecord[key])) {
+                fields.push({
+                  fieldName: key,
+                  oldValue: dstRecord[key],
+                  newValue: value,
+                });
+              }
+            } else {
+              fields.push({
+                fieldName: key,
+                oldValue: dstRecord[key],
+                newValue: value,
+              });
+            }
           }
         }
 
@@ -163,6 +174,19 @@ export class SyncEngine<
     return { inserted, deleted, updated };
   }
 
+  // to compare two objects
+  private _shallowEqual(src: Record<any, any>, dst: Record<any, any>) {
+    if (typeof src !== "object" || typeof dst !== "object") {
+      return false;
+    }
+    for (let key in src) {
+      if (src[key] !== dst[key]) {
+        return false;
+      }
+    }
+    return true;
+  }
+
   public async sync(): Promise<{
     inserts: any[] | null;
     deletes: any[] | null;
@@ -225,3 +249,63 @@ export class SyncEngine<
     return results;
   }
 }
+
+// sample usage
+const src = [
+  { id: 1, company: 1, firstName: "John", lastName: "Doe", age: null },
+  { id: 1, company: 2, firstName: "John", lastName: "Doe", age: null },
+  { id: 2, company: 1, firstName: "Jane", lastName: "Diana", age: null },
+  { id: 4, company: 1, firstName: "Rid", lastName: "Lomba", age: 25 },
+  { id: 5, company: 1, firstName: "Homa", lastName: "Shiri", age: 30 },
+];
+const dst = [
+  { id: 1, company: 1, FullName: "John Doe", bio: { age: null } },
+  { id: 3, company: 1, FullName: "Doe Risko", bio: { age: 30 } },
+  { id: 4, company: 1, FullName: "Fids Almo", bio: { age: 26 } },
+  { id: 5, company: 1, FullName: "Homa Shiri", bio: { age: 30 } },
+];
+const keys = ["id", "company"];
+
+const engine = new SyncEngine<typeof src, typeof dst>({
+  src,
+  dst,
+  keys,
+  mappings: [
+    {
+      fieldName: "FullName",
+      fn: async (row) => {
+        await new Promise((resolve) => setTimeout(resolve, 100));
+        return `${row.firstName} ${row.lastName}`;
+      },
+    },
+    { fieldName: "id", fn: (row) => row.id },
+    { fieldName: "company", fn: (row) => row.company },
+    {
+      fieldName: "bio",
+      fn: (row) => {
+        return {
+          age: row.age,
+        };
+      },
+    },
+  ],
+  syncFns: {
+    insertFn: async (row) => {
+      await new Promise((resolve) => setTimeout(resolve, 500));
+      return row.id;
+    },
+    deleteFn: (row) => {
+      return row.id;
+    },
+    updateFn: async (row, fields) => {
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+      return row.id;
+    },
+  },
+});
+
+const mappings = await engine.mapFields();
+console.log(mappings);
+
+const changes = await engine.getChanges();
+console.log(JSON.stringify(changes, null, 2));