fix: deep equality check

src/object-diff.ts

@@ -62,9 +62,10 @@ function getPreviousMatch(
   prevSubValues: [string, any][] | null,
   nextSubProperty: any
 ): any | undefined {
-  const previousMatch =
+  if (!prevSubValues) {
-    prevSubValues &&
+    return undefined;
-    prevSubValues.find(([subPreviousKey]) =>
+  }
+  const previousMatch = prevSubValues.find(([subPreviousKey]) =>
     isEqual(subPreviousKey, nextSubProperty)
   );
   return previousMatch ? previousMatch[1] : undefined;
@@ -88,7 +89,6 @@ function getSubPropertiesDiff(
         subDiff = data;
       }
     }
-    if (prevSubValues) {
     if (previousMatch) {
       subPropertiesDiff.push({
         name: nextSubProperty,
@@ -100,7 +100,6 @@ function getSubPropertiesDiff(
         ...(!!subDiff && { subDiff }),
       });
     }
-    }
   });
   return subPropertiesDiff;
 }

src/utils.ts

@@ -1,6 +1,9 @@
 export function isEqual(a: any, b: any): boolean {
   if (typeof a !== typeof b) return false;
   if (Array.isArray(a)) {
+    if (a.length !== b.length) {
+      return false;
+    }
     return a.every((v, i) => JSON.stringify(v) === JSON.stringify(b[i]));
   }
   if (typeof a === "object") {

test/object-diff.test.ts

@@ -1,189 +1,154 @@
 import { getObjectDiff } from "../src/object-diff";
 
 describe("getObjectDiff", () => {
-  // it("returns an empty diff if no objects are provided", () => {
+  it("returns an empty diff if no objects are provided", () => {
-  //   expect(getObjectDiff(null, null)).toStrictEqual({
+    expect(getObjectDiff(null, null)).toStrictEqual({
-  //     type: "object",
+      type: "object",
-  //     status: "equal",
+      status: "equal",
-  //     diff: [],
+      diff: [],
-  //   });
+    });
-  // });
+  });
-  // it("consider previous object as completely deleted if no next object is provided", () => {
+  it("consider previous object as completely deleted if no next object is provided", () => {
-  //   expect(
+    expect(
-  //     getObjectDiff(
-  //       { name: "joe", age: 54, hobbies: ["golf", "football"] },
-  //       null
-  //     )
-  //   ).toStrictEqual({
-  //     type: "object",
-  //     status: "deleted",
-  //     diff: [
-  //       {
-  //         property: "name",
-  //         previousValue: "joe",
-  //         currentValue: undefined,
-  //         status: "deleted",
-  //       },
-  //       {
-  //         property: "age",
-  //         previousValue: 54,
-  //         currentValue: undefined,
-  //         status: "deleted",
-  //       },
-  //       {
-  //         property: "hobbies",
-  //         previousValue: ["golf", "football"],
-  //         currentValue: undefined,
-  //         status: "deleted",
-  //       },
-  //     ],
-  //   });
-  // });
-  // it("consider next object as completely added if no previous object is provided", () => {
-  //   expect(
-  //     getObjectDiff(null, {
-  //       name: "joe",
-  //       age: 54,
-  //       hobbies: ["golf", "football"],
-  //     })
-  //   ).toStrictEqual({
-  //     type: "object",
-  //     status: "added",
-  //     diff: [
-  //       {
-  //         property: "name",
-  //         previousValue: undefined,
-  //         currentValue: "joe",
-  //         status: "added",
-  //       },
-  //       {
-  //         property: "age",
-  //         previousValue: undefined,
-  //         currentValue: 54,
-  //         status: "added",
-  //       },
-  //       {
-  //         property: "hobbies",
-  //         previousValue: undefined,
-  //         currentValue: ["golf", "football"],
-  //         status: "added",
-  //       },
-  //     ],
-  //   });
-  // });
-  // it("detects changed between two objects", () => {
-  //   expect(
-  //     getObjectDiff(
-  //       {
-  //         id: 54,
-  //         user: {
-  //           name: "joe",
-  //           member: true,
-  //           hobbies: ["golf", "football"],
-  //           age: 66,
-  //         },
-  //       },
-  //       {
-  //         id: 54,
-  //         user: {
-  //           name: "joe",
-  //           member: false,
-  //           hobbies: ["golf", "chess"],
-  //           age: 66,
-  //         },
-  //       }
-  //     )
-  //   ).toStrictEqual({
-  //     type: "object",
-  //     status: "updated",
-  //     diff: [
-  //       {
-  //         property: "id",
-  //         previousValue: 54,
-  //         currentValue: 54,
-  //         status: "equal",
-  //       },
-  //       {
-  //         property: "user",
-  //         previousValue: {
-  //           name: "joe",
-  //           member: true,
-  //           hobbies: ["golf", "football"],
-  //           age: 66,
-  //         },
-  //         currentValue: {
-  //           name: "joe",
-  //           member: false,
-  //           hobbies: ["golf", "chess"],
-  //           age: 66,
-  //         },
-  //         status: "updated",
-  //         subPropertiesDiff: [
-  //           {
-  //             name: "name",
-  //             previousValue: "joe",
-  //             currentValue: "joe",
-  //             status: "equal",
-  //           },
-  //           {
-  //             name: "member",
-  //             previousValue: true,
-  //             currentValue: false,
-  //             status: "updated",
-  //           },
-  //           {
-  //             name: "hobbies",
-  //             previousValue: ["golf", "football"],
-  //             currentValue: ["golf", "chess"],
-  //             status: "updated",
-  //           },
-  //           {
-  //             name: "age",
-  //             previousValue: 66,
-  //             currentValue: 66,
-  //             status: "equal",
-  //           },
-  //         ],
-  //       },
-  //     ],
-  //   });
-  // });
-  it("detects changed between two deep nested objects", () => {
-    console.log(
-      "res",
-      JSON.stringify(
       getObjectDiff(
+        { name: "joe", age: 54, hobbies: ["golf", "football"] },
+        null
+      )
+    ).toStrictEqual({
+      type: "object",
+      status: "deleted",
+      diff: [
         {
-            id: 54,
+          property: "name",
-            user: {
+          previousValue: "joe",
-              name: "joe",
+          currentValue: undefined,
-              data: {
+          status: "deleted",
-                member: true,
+        },
-                hobbies: {
+        {
-                  football: ["psg"],
+          property: "age",
-                  rugby: ["france"],
+          previousValue: 54,
+          currentValue: undefined,
+          status: "deleted",
+        },
+        {
+          property: "hobbies",
+          previousValue: ["golf", "football"],
+          currentValue: undefined,
+          status: "deleted",
         },
+      ],
+    });
+  });
+  it("consider next object as completely added if no previous object is provided", () => {
+    expect(
+      getObjectDiff(null, {
+        name: "joe",
+        age: 54,
+        hobbies: ["golf", "football"],
+      })
+    ).toStrictEqual({
+      type: "object",
+      status: "added",
+      diff: [
+        {
+          property: "name",
+          previousValue: undefined,
+          currentValue: "joe",
+          status: "added",
         },
+        {
+          property: "age",
+          previousValue: undefined,
+          currentValue: 54,
+          status: "added",
         },
+        {
+          property: "hobbies",
+          previousValue: undefined,
+          currentValue: ["golf", "football"],
+          status: "added",
         },
+      ],
+    });
+  });
+  it("detects changed between two objects", () => {
+    expect(
+      getObjectDiff(
         {
           id: 54,
           user: {
             name: "joe",
-              data: {
             member: true,
-                hobbies: {
+            hobbies: ["golf", "football"],
-                  football: ["psg", "nantes"],
+            age: 66,
-                  rugby: ["france"],
           },
         },
+        {
+          id: 54,
+          user: {
+            name: "joe",
+            member: false,
+            hobbies: ["golf", "chess"],
+            age: 66,
           },
         }
-        ),
-        null,
-        2
       )
-    );
+    ).toStrictEqual({
+      type: "object",
+      status: "updated",
+      diff: [
+        {
+          property: "id",
+          previousValue: 54,
+          currentValue: 54,
+          status: "equal",
+        },
+        {
+          property: "user",
+          previousValue: {
+            name: "joe",
+            member: true,
+            hobbies: ["golf", "football"],
+            age: 66,
+          },
+          currentValue: {
+            name: "joe",
+            member: false,
+            hobbies: ["golf", "chess"],
+            age: 66,
+          },
+          status: "updated",
+          subPropertiesDiff: [
+            {
+              name: "name",
+              previousValue: "joe",
+              currentValue: "joe",
+              status: "equal",
+            },
+            {
+              name: "member",
+              previousValue: true,
+              currentValue: false,
+              status: "updated",
+            },
+            {
+              name: "hobbies",
+              previousValue: ["golf", "football"],
+              currentValue: ["golf", "chess"],
+              status: "updated",
+            },
+            {
+              name: "age",
+              previousValue: 66,
+              currentValue: 66,
+              status: "equal",
+            },
+          ],
+        },
+      ],
+    });
+  });
+  it("detects changed between two deep nested objects", () => {
     expect(
       getObjectDiff(
         {
@@ -293,7 +258,7 @@ describe("getObjectDiff", () => {
                       name: "football",
                       previousValue: ["psg"],
                       currentValue: ["psg", "nantes"],
-                      status: "updated", // error the algo says it's equal...
+                      status: "updated",
                     },
                     {
                       name: "rugby",

test/utils.test.ts

@@ -38,6 +38,7 @@ describe("isEqual", () => {
         ]
       )
     ).toBeFalsy();
+    expect(isEqual(["psg"], ["psg", "nantes"])).toBeFalsy();
   });
 });