UnderscoreJS to find results in an Angular controller - angularjs

Question

I have a controller setup with an input that takes a Purchase Order number. At the moment to get results I am setting data[0] and always returns the first result. I want to set up a validation where the the number entered will return the correct result. Before I can do that though I need to iterate through the results to just return the data I need rather than hard-coding it to the first result. I am using underscore and have set up the following but not retrieving the result I want. Please could someone just advice how I use underscore to do this?
Underscore that did not work:
var test = _.map(data, function(data) {
return {
purchaseOrderNumber: data.purchaseOrderNumber
};
});
console.log(test);
Console output:
[Object, Object]
0: Object
1: Object
length: 2
__proto__: Array[0]
The html:
<form novalidate name="goodsIssueForm" class="form-group cnc-inline-field">
<input type="number" class="form-control" name="purchaseOrderInput" ng-model="purchaseOrderInput" ng-change="resetGoodsIssueValidity()" required></input>
<button data-auto="rpoBtn" ng-click="getPurchaseOrder()" class="btn btn-primary">Find</button>
</form>
The controller:
$scope.getPurchaseOrder = function() {
var purchaseOrderNumber = $scope.purchaseOrderInput;
GoodsIssueService.getPurchaseOrders(purchaseOrderNumber)
.then(function(data) {
if ($scope.goodsIssueForm.$valid) {
$scope.goodsIssueDocument = data;
$scope.goodsIssueDocument.purchaseOrderNumber = data[0].purchaseOrderNumber;
}
})
.catch(function() {
$scope.goodsIssueForm.$setValidity('notfound', false);
});
};