Improve node client example

The existing example didn't show how to set the `x-access-token` header, so it was not really usable.

See also cs3org/cs3apis#140.

Author: michielbdejong

README.md

@@ -12,40 +12,73 @@ npm i @cs3org/node-cs3apis
 
 ## Example usage
 ```js
+const util = require('util');
 const grpc = require('grpc');
 const { GatewayAPIClient } = require('@cs3org/node-cs3apis/cs3/gateway/v1beta1/gateway_api_grpc_pb');
-const { AuthenticateRequest } = require('@cs3org/node-cs3apis/cs3/gateway/v1beta1/gateway_api_pb');
+const { AuthenticateRequest, WhoAmIRequest } = require('@cs3org/node-cs3apis/cs3/gateway/v1beta1/gateway_api_pb');
+const { ListReceivedOCMSharesRequest } = require('@cs3org/node-cs3apis/cs3/sharing/ocm/v1beta1/ocm_api_pb');
+
+// Specifies the name of the Reva access token used during requests.
+// Align this string with the server expects, in the case of revad see:
+// https://github.com/cs3org/reva/blob/v1.11.0/pkg/token/token.go#L30
+const TOKEN_HEADER = 'x-access-token';
 
 const TARGET = process.env.TARGET || 'localhost:19000';
 
-const client = new GatewayAPIClient(TARGET, grpc.credentials.createInsecure());
+function promisifyMethods(instance, methodNames) {
+  const result = {};
+  methodNames.forEach(methodName => {
+    result[methodName] = util.promisify(instance[methodName].bind(instance));
+  });
+  return result;
+}
+
+const client = promisifyMethods(new GatewayAPIClient(TARGET, grpc.credentials.createInsecure()), [
+  'authenticate',
+  'listReceivedOCMShares',
+  'whoAmI'
+]);
+
+let metadata = new grpc.Metadata();
 
-function authenticate(authType, clientId, clientSecret) {
+async function authenticate() {
   const req = new AuthenticateRequest();
-  req.setType(authType);
-  req.setClientId(clientId);
-  req.setClientSecret(clientSecret);
-  return new Promise((resolve, reject) => {
-    client.authenticate(req, (err, response) => {
-      if (err) {
-        reject(err);
-      } else {
-        resolve(response);
-      }
-    });
-  });
+  req.setType('basic');
+  req.setClientId('einstein');
+  req.setClientSecret('relativity');
+  const res = await client.authenticate(req);
+
+  // See AuthenticateResponse https://github.com/cs3org/cs3apis/blob/a86e5cb6ac360/cs3/gateway/v1beta1/gateway_api.proto#L415
+  const user = res.getUser();
+  // * User https://github.com/cs3org/cs3apis/blob/a86e5cb6ac360/cs3/identity/user/v1beta1/resources.proto#L53
+  const displayName = user.getDisplayName();
+  console.log('DisplayName from AuthenticateResponse:', displayName);
+
+  // add the token to the metadata for subsequent client calls
+  const token = res.getToken();
+  metadata.add(TOKEN_HEADER, token);
+  // one exception is the 'WhoAmI' method, which takes the token as a request parameter
+  return token;
+}
+
+async function whoAmI(token) {
+  const req = new WhoAmIRequest();
+  req.setToken(token);
+  const res = await client.whoAmI(req /* , metadata */);
+  console.log('DisplayName from WhoAmIResponse:', res.getUser().getDisplayName());
+}
+
+async function listReceivedOCMShares() {
+  const req = new ListReceivedOCMSharesRequest();
+  // req.setToken(token);
+  const shares = await client.listReceivedOCMShares(req, metadata);
+  console.log('SharesList from ListReceivedOCMSharesResponse:', shares.getSharesList());
 }
 
 async function example() {
-  try {
-    const res = await authenticate('basic', 'einstein', 'relativity');
-    // See:
-    // * AuthenticateResponse https://github.com/cs3org/cs3apis/blob/a86e5cb6ac360/cs3/gateway/v1beta1/gateway_api.proto#L415
-    // * User https://github.com/cs3org/cs3apis/blob/a86e5cb6ac360/cs3/identity/user/v1beta1/resources.proto#L53
-    console.log(res.getUser().getDisplayName());
-  } catch (e) {
-    console.error(e);
-  }
+  const token = await authenticate();
+  await whoAmI(token);
+  await listReceivedOCMShares();
 }
 
 // ...