Merge branch 'development' into fix/instant/signature-denied

* development: (914 commits)
  Unfix compiler version except for top level contracts
  Move OrderValidator to extensions
  Update CHANGELOG
  Remove assembly version of matchOrders
  Add getOrderInfo check before calling fillOrder
  Update comments and hard code function selector constants
  Fix build after rebase
  update comments
  Fix build and add back tests
  Update dependency paths
  Add OrderMatcher tests
  feat: Add OrderMatcher contract that takes spread in multiple assets by calling `matchOrders` followed by `fillOrder`
  Update CHANGELOG
  Use more efficient equality checks
  Add note about input validation
  Use more efficient check for overflow
  Check if amount == 0 before doing division
  Reapply prettier
  New relayers
  feat(sra_client.py): Test deployed pkg via tox
  ...

1 files changed, 65 insertions, 1 deletions

diff --git a/packages/order-watcher/src/types.ts b/packages/order-watcher/src/types.ts
index 8078dd971..2b529a939 100644
--- a/packages/order-watcher/src/types.ts
+++ b/packages/order-watcher/src/types.ts
@@ -1,4 +1,4 @@
-import { OrderState } from '@0x/types';
+import { OrderState, SignedOrder } from '@0x/types';
 import { LogEntryEvent } from 'ethereum-types';
 
 export enum OrderWatcherError {
@@ -31,3 +31,67 @@ export enum InternalOrderWatcherError {
     ZrxNotInTokenRegistry = 'ZRX_NOT_IN_TOKEN_REGISTRY',
     WethNotInTokenRegistry = 'WETH_NOT_IN_TOKEN_REGISTRY',
 }
+
+export enum OrderWatcherMethod {
+    // Methods initiated by the user.
+    GetStats = 'GET_STATS',
+    AddOrder = 'ADD_ORDER',
+    RemoveOrder = 'REMOVE_ORDER',
+    // These are spontaneous; they are primarily orderstate changes.
+    Update = 'UPDATE',
+    // `subscribe` and `unsubscribe` are methods of OrderWatcher, but we don't
+    // need to expose them to the WebSocket server user because the user implicitly
+    // subscribes and unsubscribes by connecting and disconnecting from the server.
+}
+
+// Users have to create a json object of this format and attach it to
+// the data field of their WebSocket message to interact with the server.
+export type WebSocketRequest = AddOrderRequest | RemoveOrderRequest | GetStatsRequest;
+
+export interface AddOrderRequest {
+    id: number;
+    jsonrpc: string;
+    method: OrderWatcherMethod.AddOrder;
+    params: { signedOrder: SignedOrder };
+}
+
+export interface RemoveOrderRequest {
+    id: number;
+    jsonrpc: string;
+    method: OrderWatcherMethod.RemoveOrder;
+    params: { orderHash: string };
+}
+
+export interface GetStatsRequest {
+    id: number;
+    jsonrpc: string;
+    method: OrderWatcherMethod.GetStats;
+}
+
+// Users should expect a json object of this format in the data field
+// of the WebSocket messages that the server sends out.
+export type WebSocketResponse = SuccessfulWebSocketResponse | ErrorWebSocketResponse;
+
+export interface SuccessfulWebSocketResponse {
+    id: number;
+    jsonrpc: string;
+    method: OrderWatcherMethod;
+    result: OrderState | GetStatsResult | undefined; // result is undefined for ADD_ORDER and REMOVE_ORDER
+}
+
+export interface ErrorWebSocketResponse {
+    id: number | null;
+    jsonrpc: string;
+    method: null;
+    error: JSONRPCError;
+}
+
+export interface JSONRPCError {
+    code: number;
+    message: string;
+    data?: string | object;
+}
+
+export interface GetStatsResult {
+    orderCount: number;
+}