add rest/non-browser session, which we can create a lot more off

src/rest/session.js

@@ -0,0 +1,88 @@
+/*
+Copyright 2018 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+const request = require('request-promise-native');
+const RestRoom = require('./room');
+const {approveConsent} = require('./consent');
+
+module.exports = class RestSession {
+    constructor(credentials) {
+        this.credentials = credentials;
+    }
+
+    _post(csApiPath, body) {
+        return this._request("POST", csApiPath, body);
+    }
+
+    _put(csApiPath, body) {
+        return this._request("PUT", csApiPath, body);
+    }
+
+    async _request(method, csApiPath, body) {
+        try {
+            const responseBody = await request({
+                url: `${this.credentials.hsUrl}/_matrix/client/r0${csApiPath}`,
+                method,
+                headers: {
+                    "Authorization": `Bearer ${this.credentials.accessToken}`
+                },
+                json: true,
+                body
+            });
+            return responseBody;
+
+        } catch(err) {
+            const responseBody = err.response.body;
+            if (responseBody.errcode === 'M_CONSENT_NOT_GIVEN') {
+                await approveConsent(responseBody.consent_uri);
+                return this._request(method, csApiPath, body);
+            } else if(responseBody && responseBody.error) {
+                throw new Error(`${method} ${csApiPath}: ${responseBody.error}`);
+            } else {
+                throw new Error(`${method} ${csApiPath}: ${err.response.statusCode}`);
+            }
+        }
+    }
+
+    async join(roomId) {
+        const {room_id} = await this._post(`/rooms/${roomId}/join`);
+        return new RestRoom(this, room_id);
+    }
+
+
+    async createRoom(name, options) {
+        const body = {
+            name,
+        };
+        if (options.invite) {
+            body.invite = options.invite;
+        }
+        if (options.public) {
+            body.visibility = "public";
+        } else {
+            body.visibility = "private";
+        }
+        if (options.dm) {
+            body.is_direct = true;
+        }
+        if (options.topic) {
+            body.topic = options.topic;
+        }
+
+        const {room_id} = await this._post(`/createRoom`, body);
+        return new RestRoom(this, room_id);
+    }
+}