merge.all tests and implementation

index.js

@@ -68,6 +68,17 @@ function deepmerge(target, source, optionsArgument) {
     }
 }
 
+deepmerge.all = function deepmergeAll(array, optionsArgument) {
+    if (!Array.isArray(array) || array.length < 2) {
+        throw new Error('first argument should be an array with at least two elements')
+    }
+
+    // we are sure there are at least 2 values, so it is safe to have no initial value
+    return array.reduce(function(prev, next) {
+        return deepmerge(prev, next, optionsArgument)
+    })
+}
+
 return deepmerge
 
 }));

test/merge-all.js

@@ -0,0 +1,67 @@
+var merge = require('../')
+var test = require('tap').test
+
+test('throw error if first argument is not an array', function(t) {
+    t.throws(merge.all.bind(null, { example: true }, { another: '2' }), Error)
+    t.end()
+})
+
+test('throw error if first argument is an array with least than two elements', function(t) {
+    t.throws(merge.all.bind(null, [{ example: true }]), Error)
+    t.end()
+})
+
+test('execute correctly if options object were not passed', function(t) {
+    var arrayToMerge = [{ example: true }, { another: '123' }]
+    t.doesNotThrow(merge.all.bind(null, arrayToMerge))
+    t.end()
+})
+
+test('execute correctly if options object were passed', function(t) {
+    var arrayToMerge = [{ example: true }, { another: '123' }]
+    t.doesNotThrow(merge.all.bind(null, arrayToMerge, { clone:true }))
+    t.end()
+})
+
+test('invoke merge on every item in array should result with all props', function(t) {
+    var firstObject = { first: true }
+    var secondObject = { second: false }
+    var thirdObject = { third: 123 }
+    var fourthObject = { fourth: 'some string' }
+
+    var mergedObject = merge.all([firstObject, secondObject, thirdObject, fourthObject])
+
+    t.ok(mergedObject.first === true)
+    t.ok(mergedObject.second === false)
+    t.ok(mergedObject.third === 123)
+    t.ok(mergedObject.fourth === 'some string')
+    t.end()
+})
+
+test('invoke merge on every item in array with clone should clone all elements', function(t) {
+    var firstObject = { a: { d: 123 } }
+    var secondObject = { b: { e: true } }
+    var thirdObject = { c: { f: 'string' } }
+
+    var mergedWithClone = merge.all([firstObject, secondObject, thirdObject], { clone: true })
+
+    t.notEqual(mergedWithClone.a, firstObject.a)
+    t.notEqual(mergedWithClone.b, secondObject.b)
+    t.notEqual(mergedWithClone.c, thirdObject.c)
+
+    t.end()
+})
+
+test('invoke merge on every item in array without clone should not clone all elements', function(t) {
+    var firstObject = { a: { d: 123 } }
+    var secondObject = { b: { e: true } }
+    var thirdObject = { c: { f: 'string' } }
+
+    var mergedWithoutClone = merge.all([firstObject, secondObject, thirdObject])
+
+    t.equal(mergedWithoutClone.a, firstObject.a)
+    t.equal(mergedWithoutClone.b, secondObject.b)
+    t.equal(mergedWithoutClone.c, thirdObject.c)
+
+    t.end()
+})