Merge pull request #1 from DoneDeal0/deep-nested-diff

feat: start deep nested diff

src/model.ts

@@ -27,6 +27,7 @@ export type Subproperties = {
   previousValue: any;
   currentValue: any;
   status: DiffStatus;
+  subDiff?: Subproperties[];
 };
 
 export type ObjectDiff = {

src/object-diff.ts

@@ -58,6 +58,52 @@ function formatSingleObjectDiff(
   };
 }
 
+function getPreviousMatch(
+  prevSubValues: [string, any][] | null,
+  nextSubProperty: any
+): any | undefined {
+  if (!prevSubValues) {
+    return undefined;
+  }
+  const previousMatch = prevSubValues.find(([subPreviousKey]) =>
+    isEqual(subPreviousKey, nextSubProperty)
+  );
+  return previousMatch ? previousMatch[1] : undefined;
+}
+
+function getSubPropertiesDiff(
+  previousValue: Record<string, any> | undefined,
+  nextValue: Record<string, any>
+): Subproperties[] {
+  const subPropertiesDiff: Subproperties[] = [];
+  const prevSubValues = previousValue ? Object.entries(previousValue) : null;
+  let subDiff: Subproperties["subDiff"];
+  Object.entries(nextValue).forEach(([nextSubProperty, nextSubValue]) => {
+    const previousMatch = getPreviousMatch(prevSubValues, nextSubProperty);
+    if (isObject(nextSubValue)) {
+      const data: Subproperties[] = getSubPropertiesDiff(
+        previousMatch,
+        nextSubValue
+      );
+      if (data && data.length > 0) {
+        subDiff = data;
+      }
+    }
+    if (previousMatch) {
+      subPropertiesDiff.push({
+        name: nextSubProperty,
+        previousValue: previousMatch,
+        currentValue: nextSubValue,
+        status: isEqual(previousMatch, nextSubValue)
+          ? STATUS.EQUAL
+          : STATUS.UPDATED,
+        ...(!!subDiff && { subDiff }),
+      });
+    }
+  });
+  return subPropertiesDiff;
+}
+
 export function getObjectDiff(
   prevData: ObjectData,
   nextData: ObjectData
@@ -80,27 +126,10 @@ export function getObjectDiff(
     const previousValue = prevData[nextProperty];
 
     if (isObject(nextValue)) {
-      const prevSubValues = previousValue
-        ? Object.entries(previousValue)
-        : null;
-      const subPropertiesDiff: Subproperties[] = [];
-      Object.entries(nextValue).forEach(([nextSubProperty, nextSubValue]) => {
-        if (prevSubValues) {
-          const previousMatch = prevSubValues.find(([subPreviousKey]) =>
-            isEqual(subPreviousKey, nextSubProperty)
-          );
-          if (previousMatch) {
-            subPropertiesDiff.push({
-              name: nextSubProperty,
-              previousValue: previousMatch[1],
-              currentValue: nextSubValue,
-              status: isEqual(previousMatch[1], nextSubValue)
-                ? STATUS.EQUAL
-                : STATUS.UPDATED,
-            });
-          }
-        }
-      });
+      const subPropertiesDiff: Subproperties[] = getSubPropertiesDiff(
+        previousValue,
+        nextValue
+      );
       const _status = subPropertiesDiff.some(
         (property) => property.status !== STATUS.EQUAL
       )

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

@@ -148,4 +148,131 @@ describe("getObjectDiff", () => {
       ],
     });
   });
+  it("detects changed between two deep nested objects", () => {
+    expect(
+      getObjectDiff(
+        {
+          id: 54,
+          user: {
+            name: "joe",
+            data: {
+              member: true,
+              hobbies: {
+                football: ["psg"],
+                rugby: ["france"],
+              },
+            },
+          },
+        },
+        {
+          id: 54,
+          user: {
+            name: "joe",
+            data: {
+              member: true,
+              hobbies: {
+                football: ["psg", "nantes"],
+                rugby: ["france"],
+              },
+            },
+          },
+        }
+      )
+    ).toStrictEqual({
+      type: "object",
+      status: "updated",
+      diff: [
+        {
+          property: "id",
+          previousValue: 54,
+          currentValue: 54,
+          status: "equal",
+        },
+        {
+          property: "user",
+          previousValue: {
+            name: "joe",
+            data: {
+              member: true,
+              hobbies: {
+                football: ["psg"],
+                rugby: ["france"],
+              },
+            },
+          },
+          currentValue: {
+            name: "joe",
+            data: {
+              member: true,
+              hobbies: {
+                football: ["psg", "nantes"],
+                rugby: ["france"],
+              },
+            },
+          },
+          status: "updated",
+          subPropertiesDiff: [
+            {
+              name: "name",
+              previousValue: "joe",
+              currentValue: "joe",
+              status: "equal",
+            },
+            {
+              name: "data",
+              previousValue: {
+                member: true,
+                hobbies: {
+                  football: ["psg"],
+                  rugby: ["france"],
+                },
+              },
+              currentValue: {
+                member: true,
+                hobbies: {
+                  football: ["psg", "nantes"],
+                  rugby: ["france"],
+                },
+              },
+              status: "updated",
+              subDiff: [
+                {
+                  name: "member",
+                  previousValue: true,
+                  currentValue: true,
+                  status: "equal",
+                },
+                {
+                  name: "hobbies",
+                  previousValue: {
+                    football: ["psg"],
+                    rugby: ["france"],
+                  },
+                  currentValue: {
+                    football: ["psg", "nantes"],
+                    rugby: ["france"],
+                  },
+                  status: "updated",
+                  subDiff: [
+                    {
+                      name: "football",
+                      previousValue: ["psg"],
+                      currentValue: ["psg", "nantes"],
+                      status: "updated",
+                    },
+                    {
+                      name: "rugby",
+                      previousValue: ["france"],
+                      currentValue: ["france"],
+                      status: "equal",
+                    },
+                  ],
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
 });

test/utils.test.ts

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