2 files changed, 74 insertions, 0 deletions
diff --git a/packages/connect/src/utils/orderbook_channel_message_parsers.ts b/packages/connect/src/utils/orderbook_channel_message_parsers.ts
new file mode 100644
index 000000000..b590b189b
--- /dev/null
+++ b/packages/connect/src/utils/orderbook_channel_message_parsers.ts
@@ -0,0 +1,43 @@
+import * as _ from 'lodash';
+import {SignedOrder} from '0x.js';
+import {assert} from '@0xproject/assert';
+import {schemas} from '@0xproject/json-schemas';
+import {
+    OrderbookChannelMessage,
+    OrderbookChannelMessageTypes,
+} from '../types';
+import {typeConverters} from './type_converters';
+
+export const orderbookChannelMessageParsers = {
+    parser(utf8Data: string): OrderbookChannelMessage {
+        const messageObj = JSON.parse(utf8Data);
+        const type: string = _.get(messageObj, 'type');
+        assert.assert(!_.isUndefined(type), `Message is missing a type parameter: ${utf8Data}`);
+        switch (type) {
+            case (OrderbookChannelMessageTypes.Snapshot): {
+                assert.doesConformToSchema('message', messageObj, schemas.relayerApiOrderbookChannelSnapshotSchema);
+                const orderbook = messageObj.payload;
+                typeConverters.convertOrderbookStringFieldsToBigNumber(orderbook);
+                return {
+                    type,
+                    payload: orderbook,
+                };
+            }
+            case (OrderbookChannelMessageTypes.Update): {
+                assert.doesConformToSchema('message', messageObj, schemas.relayerApiOrderbookChannelUpdateSchema);
+                const order = messageObj.payload;
+                typeConverters.convertOrderStringFieldsToBigNumber(order);
+                return {
+                    type,
+                    payload: order,
+                };
+            }
+            default: {
+                return {
+                    type: OrderbookChannelMessageTypes.Unknown,
+                    payload: undefined,
+                };
+            }
+        }
+    },
+};
diff --git a/packages/connect/src/utils/type_converters.ts b/packages/connect/src/utils/type_converters.ts
new file mode 100644
index 000000000..bf17a5629
--- /dev/null
+++ b/packages/connect/src/utils/type_converters.ts
@@ -0,0 +1,31 @@
+import * as _ from 'lodash';
+import {BigNumber} from 'bignumber.js';
+
+// TODO: convert all of these to non-mutating, pure functions
+export const typeConverters = {
+    convertOrderbookStringFieldsToBigNumber(orderbook: object): void {
+        _.each(orderbook, (orders: object[]) => {
+            _.each(orders, (order: object) => this.convertOrderStringFieldsToBigNumber(order));
+        });
+    },
+    convertOrderStringFieldsToBigNumber(order: object): void {
+        this.convertStringsFieldsToBigNumbers(order, [
+            'makerTokenAmount',
+            'takerTokenAmount',
+            'makerFee',
+            'takerFee',
+            'expirationUnixTimestampSec',
+            'salt',
+        ]);
+    },
+    convertBigNumberFieldsToStrings(obj: object, fields: string[]): void {
+        _.each(fields, field => {
+            _.update(obj, field, (value: BigNumber) => value.toString());
+        });
+    },
+    convertStringsFieldsToBigNumbers(obj: object, fields: string[]): void {
+        _.each(fields, field => {
+            _.update(obj, field, (value: string) => new BigNumber(value));
+        });
+    },
+};