add error log handler (#218)

* add error log handler

* use fs/promises

lib/util/dump_error_log.js

@@ -0,0 +1,28 @@
+'use strict'
+
+const os = require('os')
+const { appendFile, mkdir } = require('fs/promises')
+const { existsSync } = require('fs')
+const send = require('../util/ws/send')
+
+const LOG_DIR_PATH = `${os.tmpdir()}/bfx-hf-ui-logs`
+const APP_LOG_PATH = `${LOG_DIR_PATH}/app.log`
+
+/**
+ * Store the error log in app.log file
+ * @param {object} ws
+ * @param {string} errorLog - json string
+ * @returns {void}
+ */
+module.exports = async (ws, errorLog) => {
+ try {
+ if (!existsSync(LOG_DIR_PATH)) {
+ await mkdir(LOG_DIR_PATH)
+ }
+
+ await appendFile(APP_LOG_PATH, `${errorLog}${os.EOL}`)
+ } catch (e) {
+ console.error('ERR_APP_LOG', e)
+ send(ws, ['data.app_log_error', e.message])
+ }
+}

lib/ws_servers/api/handlers/on_dump_error_log.js

@@ -0,0 +1,19 @@
+'use strict'
+
+const send = require('../../../util/ws/send')
+const validateParams = require('../../../util/ws/validate_params')
+const dumpErrorLog = require('../../../util/dump_error_log')
+
+module.exports = async (server, ws, msg) => {
+ const [, errorLog] = msg
+
+ const validRequest = validateParams(ws, {
+ errorLog: { type: 'string', v: errorLog }
+ })
+
+ if (!validRequest) {
+ return send(ws, ['data.app_log', 'failed'])
+ }
+
+ await dumpErrorLog(ws, errorLog)
+}

lib/ws_servers/api/index.js

@@ -46,6 +46,8 @@ const onFeatureFlagsRequest = require('./handlers/on_feature_flags_request')
 
 const onChangeMode = require('./handlers/on_change_mode')
 
+const onDumpErrorLog = require('./handlers/on_dump_error_log')
+
 const getUserSettings = require('../../util/user_settings')
 const algoHost = require('bfx-hf-algo')
 
@@ -118,7 +120,9 @@ module.exports = class APIWSServer extends WSServer {
  'algo_order.remove': onAlgoOrderRemove,
  'algo_order.pause': onAlgoPause,
  'settings.update': onSettingsUpdate,
- 'favourite_trading_pairs.save': onSaveFavouriteTradingPairs
+ 'favourite_trading_pairs.save': onSaveFavouriteTradingPairs,
+
+ 'error_log.dump': onDumpErrorLog
  }
  })
 

test/unit/lib/util/dump_error_log.js

@@ -0,0 +1,77 @@
+/* eslint-disable no-unused-expressions */
+/* eslint-env mocha */
+'use strict'
+
+const chai = require('chai')
+const sinon = require('sinon')
+const proxyquire = require('proxyquire')
+const fs = require('fs')
+const { expect } = chai
+
+describe('dump error log', () => {
+ let mkdirStub
+ let appendFileStub
+ let existsSyncStub
+ let sendStub
+ let dumpErrorLog
+
+ beforeEach(() => {
+ mkdirStub = sinon.stub(fs.promises, 'mkdir')
+ appendFileStub = sinon.stub(fs.promises, 'appendFile')
+ existsSyncStub = sinon.stub(fs, 'existsSync')
+ sendStub = sinon.stub()
+
+ dumpErrorLog = proxyquire('../../../../lib/util/dump_error_log', {
+ 'fs/promises': {
+ mkdir: mkdirStub,
+ appendFile: appendFileStub
+ },
+ fs: {
+ existsSync: existsSyncStub
+ },
+ './ws/send': sendStub
+ })
+ })
+
+ afterEach(() => {
+ mkdirStub.restore()
+ appendFileStub.restore()
+ existsSyncStub.restore()
+ sendStub.reset()
+ })
+
+ it('should create the log directory if it does not exist', async () => {
+ existsSyncStub.returns(false)
+
+ await dumpErrorLog({}, {})
+
+ expect(mkdirStub.calledOnce).to.be.true
+ })
+
+ it('should not create the log directory if it is already exist', async () => {
+ existsSyncStub.returns(true)
+
+ await dumpErrorLog({}, {})
+
+ expect(mkdirStub.notCalled).to.be.true
+ })
+
+ it('should append the error log to the app.log file', async () => {
+ existsSyncStub.returns(true)
+
+ const errorLog = JSON.stringify({ error: 'app error' })
+ await dumpErrorLog({}, errorLog)
+
+ expect(appendFileStub.calledOnce).to.be.true
+ expect(appendFileStub.firstCall.args[1]).to.contain(errorLog)
+ })
+
+ it('should send a ws message if an error occurs', async () => {
+ existsSyncStub.returns(false)
+ mkdirStub.rejects(new Error('MKDIR_ERROR'))
+
+ await dumpErrorLog({}, {})
+
+ expect(sendStub.calledWith({}, ['data.app_log_error', 'MKDIR_ERROR'])).to.be.true
+ })
+})