fix #83: Correctly handle changing and shrinking object arrays in diffs

SierraSoftworks · Jul 7, 2017 · 5202a5a · 5202a5a
1 parent 44cfc9f
commit 5202a5a
Show file tree

Hide file tree

Showing 3 changed files with 50 additions and 3 deletions.
diff --git a/lib/utils/Omnom.ts b/lib/utils/Omnom.ts
@@ -128,7 +128,12 @@ export class Omnom {
       let j = 0;
 
       for (; i < original.length && j < modified.length; i++) {
-          if (this.almostEqual(original[i], modified[j])) j++;
+          const equalityDistance = this.almostEqual(original[i], modified[j])
+          if (equalityDistance == 1) j++;
+          else if(equalityDistance > 0)
+            // If we would need to both pull and $set on this array, we have to
+            // just use the $set operator.
+            return this.set(changePath, modified);
           else pulls.push(original[i]);
       }
 
@@ -143,7 +148,7 @@ export class Omnom {
 
       // If we have a smaller target array than our source, we will need to re-create it
       // regardless (if we want to do so in a single operation anyway)
-      else return this.set(changePath, modified);
+      return this.set(changePath, modified);
     }
 
     private onLargerArray(original: any[], modified: any[], changePath: string): void {

diff --git a/test/Omnom.ts b/test/Omnom.ts
@@ -303,5 +303,32 @@ describe("Omnom",() => {
 
             chai.expect(Omnom.diff(oldObject, newObject)).to.exist.and.be.eql(expectedDiff);
         });
+
+        it("should handle complex array objects which should be replaced in a smaller array", () => {
+            let oldObject = { a: [{x: 1, y: "a"}, {x: 2, y: "b"}, {x: 3, y: "c"}, {x: 4, y: "d"}]};
+            let newObject = { a: [{x: 1, y: "z"}, {x: 2, y: "y"}] };
+            let expectedDiff = {
+                $set: {
+                    "a": [{x: 1, y: "z"}, {x: 2, y: "y"}]
+                }
+            };
+
+            chai.expect(Omnom.diff(oldObject, newObject)).to.exist.and.be.eql(expectedDiff);
+        });
+
+        it("should handle complex array objects which should be replaced in a larger array", () => {
+            let oldObject = { a: [{x: 1, y: "a"}, {x: 2, y: "b"}]};
+            let newObject = { a: [{x: 1, y: "z"}, {x: 2, y: "y"}, {x: 3, y: "x"}, {x: 4, y: "w"}] };
+            let expectedDiff = {
+                $set: {
+                    "a.0.y": "z",
+                    "a.1.y": "y",
+                    "a.2": {x: 3, y: "x"},
+                    "a.3": {x: 4, y: "w"}
+                }
+            };
+
+            chai.expect(Omnom.diff(oldObject, newObject)).to.exist.and.be.eql(expectedDiff);
+        });
     });
 });
diff --git a/test/issues/#83.ts b/test/issues/#83.ts
@@ -1,4 +1,5 @@
 import * as Iridium from "../../iridium";
+import {Omnom} from "../../lib/utils/Omnom";
 import * as chai from "chai";
 
 interface TestDocument {
@@ -31,7 +32,7 @@ describe("issues", () => {
         });
     }
 
-    describe.only("#83", () => {
+    describe("#83", () => {
         let model = new Iridium.Model<TestDocument, Test>(core, Test);
 
         it("track.save should update track accordingly", () => {
@@ -44,5 +45,19 @@ describe("issues", () => {
                 chai.expect(test.stuff).to.eql(build_dataset(20, 14));
             });
         });
+
+        it("should derive the correct change definition", () => {
+            const diff = Omnom.diff({
+                stuff: build_dataset(1, 19)
+            }, {
+                stuff: build_dataset(20, 14)
+            });
+
+            chai.expect(diff).to.eql({
+                "$set": {
+                    stuff: build_dataset(20, 14)
+                }
+            });
+        });
     });
 });