Consistent roles handling

lib/Connection.d.ts

@@ -34,8 +34,7 @@ export default class Connection {
     MASTER: string;
     DATA: string;
     INGEST: string;
-    COORDINATING: string;
-    MACHINE_LEARNING: string;
+    ML: string;
   };
   url: URL;
   ssl: SecureContextOptions | null;

lib/Connection.js

@@ -19,7 +19,7 @@ class Connection {
 
     this._openRequests = 0
     this._status = opts.status || Connection.statuses.ALIVE
-    this.roles = opts.roles || defaultRoles
+    this.roles = Object.assign({}, defaultRoles, opts.roles) || Object.assign({}, defaultRoles)
 
     if (!['http:', 'https:'].includes(this.url.protocol)) {
       throw new ConfigurationError(`Invalid protocol: '${this.url.protocol}'`)
@@ -199,16 +199,14 @@ Connection.roles = {
   MASTER: 'master',
   DATA: 'data',
   INGEST: 'ingest',
-  COORDINATING: 'coordinating',
-  MACHINE_LEARNING: 'machine_learning'
+  ML: 'ml'
 }
 
 const defaultRoles = {
   [Connection.roles.MASTER]: true,
   [Connection.roles.DATA]: true,
   [Connection.roles.INGEST]: true,
-  [Connection.roles.COORDINATING]: true,
-  [Connection.roles.MACHINE_LEARNING]: true
+  [Connection.roles.ML]: false
 }
 
 const validStatuses = Object.keys(Connection.statuses)

lib/ConnectionPool.js

@@ -314,7 +314,6 @@ class ConnectionPool {
 
   /**
    * Transforms the nodes objects to a host object.
-   * TODO: handle ssl and agent options
    *
    * @param {object} nodes
    * @returns {array} hosts
@@ -331,13 +330,20 @@ class ConnectionPool {
       address = address.slice(0, 4) === 'http'
         ? address
         : 'http://' + address
+      const roles = node.roles.reduce((acc, role) => {
+        acc[role] = true
+        return acc
+      }, {})
+
       hosts.push({
         url: new URL(address),
         id: ids[i],
-        roles: node.roles.reduce((acc, role) => {
-          acc[role] = true
-          return acc
-        }, {})
+        roles: Object.assign({
+          [Connection.roles.MASTER]: true,
+          [Connection.roles.DATA]: true,
+          [Connection.roles.INGEST]: true,
+          [Connection.roles.ML]: false
+        }, roles)
       })
     }
 
@@ -371,9 +377,9 @@ ConnectionPool.resurrectStrategies = {
 
 function defaultNodeFilter (node) {
   // avoid master only nodes
-  if (!!node.roles.master === true &&
-      !!node.roles.data === false &&
-      !!node.roles.ingest === false) {
+  if (node.roles.master === true &&
+      node.roles.data === false &&
+      node.roles.ingest === false) {
     return false
   }
   return true