cosmos-trigger-post-addRefund-complete.ts

function addRefund() {
    // capture the contextual variables we'll need
    var request = getContext().getRequest();
    var collection = getContext().getCollection();

    // run the core logic of the trigger
    addRefundImpl(request, collection);
}

function addRefundImpl(request: IRequest, collection: ICollection) {
    if (request.getOperationType() == "Delete") {
        // this is not a 'Create' or 'Replace' operation, so we can ignore it in this trigger
        return;
    }

    var document = request.getBody() as BaseDocument;
    if (document.type != DocumentTypes.Order) {
        // this is not an order, so we can ignore it in this trigger
        return;
    }
    var orderDocument = <OrderDocument>document;

    // check for any order items with a negative quantity
    var refundedProductIds = orderDocument.items.filter(i => i.quantity < 0).map(i => i.productId);
    if (refundedProductIds.length == 0) {
        return;
    }

    // prepare and upsert a refund document
    var refundDocument: RefundDocument = {
        id: "refund-" + orderDocument.id,
        type: DocumentTypes.Refund,
        customer: {
            id: orderDocument.customer.id
        },
        order: {
            id: orderDocument.id
        },
        refundedProducts: refundedProductIds
    }
    var inserted = collection.upsertDocument(collection.getSelfLink(), refundDocument);
    if (! inserted) {
        throw new Error("Could not insert refund document for order.");
    }
}

const enum DocumentTypes {
    Order = "order",
    Refund = "refund"
}

interface BaseDocument {
    id: string,
    type: DocumentTypes
}

interface OrderDocument extends BaseDocument {
    customer: {
        id: string
    },
    items: [
        {
            productId: string,
            quantity: number
        }
    ]
}

interface RefundDocument extends BaseDocument {
    customer: {
        id: string
    },
    order: {
        id: string
    },
    refundedProducts: string[]
}