feat: added Unflat function for

README.md

@@ -18,7 +18,7 @@ npm install @kishor82/jsonflat
 
 ## Usage
 
-To flata nested JSON object, import the `flat` function from `jsonflat` and use it as follows:
+To flat nested JSON object, import the `flat` function from `jsonflat` and use it as follows:
 
 ```javascript
 const { flat } = require("@kishor82/jsonflat");
@@ -99,6 +99,44 @@ Output:
 }
 ```
 
+### nestedObject JSON Object
+
+```javascript
+
+const { unflat } = require("@kishor82/jsonflat");
+
+const flattenedObject = {
+  "person.name.first": "John",
+  "person.name.last": "Doe",
+  "person.age": 30,
+  "person.address.city": "New York",
+  "person.address.state": "NY"
+};
+
+const nestedObject = unflat(flattenedObject);
+
+console.log(nestedObject);
+
+```
+
+Output:
+
+```json
+{
+  person: {
+    name: {
+      first: "John",
+      last: "Doe",
+    },
+    age: 30,
+    address: {
+      city: "New York",
+      state: "NY",
+    },
+  },
+};
+```
+
 ## License
 
 This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

index.js

@@ -1,7 +1,7 @@
 // Directories are not valid import targets in ESM unless they have an explicit entry point defined.
 import jsonflat from "./lib/index.js";
 
-const { flat } = jsonflat;
+const { flat, unflat } = jsonflat;
 
 // https://github.com/rollup/rollup/issues/1961#issuecomment-618345638
-export { jsonflat as default, flat };
+export { jsonflat as default, flat, unflat };

lib/index.js

@@ -17,8 +17,24 @@ const flat = (data, delimeter = ".", parentKey) => {
   }, {});
 };
 
+const unflat = (data, delimiter = ".") => {
+  return Object.keys(data).reduce((unflattenedObject, key) => {
+    const keys = key.split(delimiter);
+    keys.reduce((acc, k, i) => {
+      if (i === keys.length - 1) {
+        acc[k] = data[key];
+      } else {
+        acc[k] = acc[k] || {};
+      }
+      return acc[k];
+    }, unflattenedObject);
+    return unflattenedObject;
+  }, {});
+};
+
 const jsonflat = {
   flat,
+  unflat,
 };
 
 export default jsonflat;

test/unit/index.test.js

@@ -88,4 +88,30 @@ describe("unflat functon", () => {
       // Assert that the unflat function is defined
       expect(unflat).toBeDefined();
   });
+
+    // Test case for unflattening a simple object
+    it("Unflattens a simple object", () => {
+      const data = {
+        name: "John",
+        age: 30,
+        "address.city": "New York",
+        "address.country": "USA",
+      };
+      const expected = {
+        name: "John",
+        age: 30,
+        address: {
+          city: "New York",
+          country: "USA",
+        },
+      };
+      expect(unflat(data)).toEqual(expected);
+    });
+
+  // Test case for unflattening an empty object
+  it("returns an empty object for an empty input", () => {
+    const data = {};
+    const expected = {};
+    expect(unflat(data)).toEqual(expected);
+  });
 })