add documentation to add new grpc api functions (#21)

README.md

@@ -30,7 +30,7 @@ Running the [top-level API tests](./src/HavenoDaemon.test.tsx) is a great way to
   Example: `docker run --rm -it -v ~/git/haveno-ui-poc/config/envoy.test.yaml:/envoy.test.yaml -p 8080:8080 -p 8081:8081 envoyproxy/envoy-dev:8a2143613d43d17d1eb35a24b4a4a4c432215606 -c /envoy.test.yaml`
 5. `npm install`
 6. Modify test config as needed in [HavenoDaemon.test.tsx](./src/HavenoDaemon.test.tsx).
-7. `npm test` to run all tests or `npm run test -- -t 'my test'` to run tests by name
+7. `npm test` to run all tests or `npm run test -- -t 'my test'` to run tests by name.
 
 ## How to Update the Protobuf Client
 

docs/adding_api_functions.md

@@ -0,0 +1,13 @@
+# How to add and test new gRPC API functions in Haveno
+
+1. Follow [instructions](https://github.com/haveno-dex/haveno-ui-poc#run-tests) to run Haveno's existing API tests successfully.
+2. Define the new service or message in Haveno's [protobuf definition](../proto/src/main/proto/grpc.proto).
+3. Clean and build Haveno after modifying the protobuf definition: `make clean && make`
+4. Implement the new service in Haveno's backend, following existing patterns.<br>
+   For example, the gRPC function to get offers is implemented by [`GrpcServer`](https://github.com/haveno-dex/haveno/blob/master/daemon/src/main/java/bisq/daemon/grpc/GrpcServer.java) > [`GrpcOffersService.getOffers(...)`](https://github.com/haveno-dex/haveno/blob/b761dbfd378faf49d95090c126318b419af7926b/daemon/src/main/java/bisq/daemon/grpc/GrpcOffersService.java#L104) > [`CoreApi.getOffers(...)`](https://github.com/haveno-dex/haveno/blob/b761dbfd378faf49d95090c126318b419af7926b/core/src/main/java/bisq/core/api/CoreApi.java#L128) > [`CoreOffersService.getOffers(...)`](https://github.com/haveno-dex/haveno/blob/b761dbfd378faf49d95090c126318b419af7926b/core/src/main/java/bisq/core/api/CoreOffersService.java#L126) > [`OfferBookService.getOffers()`](https://github.com/haveno-dex/haveno/blob/b761dbfd378faf49d95090c126318b419af7926b/core/src/main/java/bisq/core/offer/OfferBookService.java#L193).
+5. Build Haveno: `make`
+6. Follow [instructions](https://github.com/haveno-dex/haveno-ui-poc#how-to-update-the-protobuf-client) to update the protobuf client in haveno-ui-poc.
+7. Add the corresponding typescript method(s) to [HavenoDaemon.tsx](https://github.com/haveno-dex/haveno-ui-poc/blob/master/src/HavenoDaemon.tsx) with clear and concise documentation.
+8. Add clean and comprehensive tests to [HavenoDaemon.test.tsx](https://github.com/haveno-dex/haveno-ui-poc/blob/master/src/HavenoDaemon.test.tsx), following existing patterns.
+9. Verify the tests with `npm run test -- -t 'my test'` to run tests by name and `npm test` to run all tests together.
+10. Open a pull request for review.

src/HavenoDaemon.tsx

@@ -56,7 +56,7 @@ class HavenoDaemon {
    * @param {string} currencyCode - currency code to get the price of
    * @return {number} the current market price of the given currency code as a ratio, e.g. XMR/ETH
    */
-  async getPrice(currencyCode: string) {
+  async getPrice(currencyCode: string): Promise<number> {
     let that = this;
     return new Promise(function(resolve, reject) {
       that._priceClient.getMarketPrice(new MarketPriceRequest().setCurrencyCode(currencyCode), {password: that._password}, function(err: grpcWeb.Error, response: MarketPriceReply) {