feat: add a diffUsing method

ecrmnn · Mar 20, 2023 · 6c3ba5d · 6c3ba5d
1 parent 84ad447
commit 6c3ba5d
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diff --git a/dist/methods/diffUsing.js b/dist/methods/diffUsing.js
@@ -0,0 +1,10 @@
+'use strict';
+
+module.exports = function diffUsing(values, callback) {
+  var collection = this.items.filter(function (item) {
+    return !(values && values.some(function (otherItem) {
+      return callback(item, otherItem) === 0;
+    }));
+  });
+  return new this.constructor(collection);
+};
diff --git a/src/index.js b/src/index.js
@@ -44,6 +44,7 @@ Collection.prototype.dd = require('./methods/dd');
 Collection.prototype.diff = require('./methods/diff');
 Collection.prototype.diffAssoc = require('./methods/diffAssoc');
 Collection.prototype.diffKeys = require('./methods/diffKeys');
+Collection.prototype.diffUsing = require('./methods/diffUsing');
 Collection.prototype.doesntContain = require('./methods/doesntContain');
 Collection.prototype.dump = require('./methods/dump');
 Collection.prototype.duplicates = require('./methods/duplicates');

diff --git a/src/methods/diffUsing.js b/src/methods/diffUsing.js
@@ -0,0 +1,9 @@
+'use strict';
+
+module.exports = function diffUsing(values, callback) {
+  const collection = this.items.filter(item => (
+    !(values && values.some(otherItem => callback(item, otherItem) === 0))
+  ));
+
+  return new this.constructor(collection);
+};
diff --git a/test/methods/diffUsing_test.js b/test/methods/diffUsing_test.js
@@ -0,0 +1,38 @@
+'use strict';
+
+module.exports = (it, expect, collect) => {
+  it('should compare the collection against a javascript array using a callback', () => {
+    const collection = collect(['fr', 'en_gb', 'hr']);
+    const diffArray = ['en_gb', 'hr'];
+
+    const diff = collection.diffUsing(diffArray, (a, b) => a.localeCompare(b));
+
+    expect(diff.all()).to.eql(['fr']);
+    expect(collection.all()).to.eql(['fr', 'en_gb', 'hr']);
+  });
+
+  it('should compare the collection against another collection using on a callback', () => {
+    const collection = collect([
+      { name: 'Alice', age: 25 },
+      { name: 'Bob', age: 30 },
+      { name: 'Charlie', age: 35 },
+    ]);
+
+    const diffCollection = collect([
+      { name: 'Bob', age: 30 },
+      { name: 'Charlie', age: 35 },
+      { name: 'David', age: 40 },
+    ]);
+
+    const diff = collection.diffUsing(diffCollection, (a, b) => a.age - b.age);
+
+    expect(diff.all()).to.be.eql([{ name: 'Alice', age: 25 }]);
+  });
+
+  it('does not return a difference when the comparison is null', () => {
+    const collection = collect(['apple', 'banana', 'cherry']);
+    const diff = collection.diffUsing(null, (a, b) => a.localeCompare(b));
+
+    expect(diff.all()).to.eql(['apple', 'banana', 'cherry']);
+  });
+};