Switch to the recommended-type-checked linter preset

eslint.config.mjs

@@ -15,7 +15,7 @@ const compat = new FlatCompat({
 });
 
 export default [
-  ...compat.extends("eslint:recommended", "plugin:@typescript-eslint/recommended"),
+  ...compat.extends("eslint:recommended", "plugin:@typescript-eslint/recommended-type-checked"),
   {
     plugins: {
       "@typescript-eslint": typescriptEslint,
@@ -25,14 +25,19 @@ export default [
       globals: {
         ...globals.node,
       },
-
       parser: tsParser,
+      parserOptions: {
+        project: "./tsconfig.json"
+      },
       ecmaVersion: 2021,
       sourceType: "module",
     },
 
     rules: {
       "no-console": "error",
+      // We have type-hinted functions that in their dummy implementations return static data
+      "@typescript-eslint/require-await": "off",
+      "@typescript-eslint/return-await": "error"
     },
   },
 ];

package.json

@@ -34,6 +34,7 @@
     "@influxdata/influxdb-client": "^1.33.2",
     "modbus-serial": "^8.0.16",
     "mqtt": "^5.1.2",
+    "set-interval-async": "^3.0.3",
     "slugify": "^1.6.6",
     "winston": "^3.11.0",
     "ws": "^8.17.1",

src/characteristics.ts

@@ -18,5 +18,5 @@ export const pollCharacteristicsSensors = async (
     promises.push(sensor.pollFunc(timestamp, c))
   }
 
-  return await Promise.all(promises)
+  return Promise.all(promises)
 }

src/circuit.ts

@@ -33,5 +33,5 @@ export const pollPowerSensors = async (
     promises.push(sensor.pollFunc(timestamp, circuit, existingSensorData))
   }
 
-  return await Promise.all(promises)
+  return Promise.all(promises)
 }

src/config.ts

@@ -189,7 +189,7 @@ export const resolveAndValidateConfig = (config: Config): Config => {
         circuit.sensor.pollFunc = getDummySensorData
         break
       default:
-        throw new Error(`Unrecognized sensor type ${circuit.sensor.type}`)
+        throw new Error(`Unrecognized sensor type ${circuit.sensor.type as string}`)
     }
   }
 

src/eachwatt.ts

@@ -12,6 +12,7 @@ import { createLogger, LogLevel, setLogLevel } from './logger'
 import { setRequestTimeout as setHttpRequestTimeout } from './http/client'
 import { setRequestTimeout as setModbusRequestTimeout } from './modbus/client'
 import { applyFilters } from './filter/filter'
+import { setIntervalAsync } from 'set-interval-async'
 
 // Set up a signal handler, so we can exit on Ctrl + C when run from Docker
 process.on('SIGINT', () => {
@@ -95,7 +96,7 @@ const mainPollerFunc = async (config: Config) => {
   }
 }
 
-;(async () => {
+void (async () => {
   const configFile = argv.config as string
   if (!fs.existsSync(configFile)) {
     logger.error(`Configuration ${configFile} file does not exist or is not readable`)
@@ -120,13 +121,13 @@ const mainPollerFunc = async (config: Config) => {
   })
 
   // Adjust request timeouts to be half that of the polling interval
-  const pollingInterval = config.settings.pollingInterval
+  const pollingInterval = config.settings.pollingInterval as number
   logger.info(`Polling sensors with interval ${pollingInterval} milliseconds`)
-  const timeoutMs = (pollingInterval as number) / 2
+  const timeoutMs = pollingInterval / 2
   setHttpRequestTimeout(timeoutMs)
   setModbusRequestTimeout(timeoutMs)
 
   // Start polling sensors
   await mainPollerFunc(config)
-  setInterval(mainPollerFunc, pollingInterval, config)
+  setIntervalAsync(mainPollerFunc, pollingInterval, config)
 })()

src/http/client.ts

@@ -4,7 +4,7 @@ const logger = createLogger('http')
 
 let requestTimeout = 0
 let lastTimestamp = 0
-const promiseCache = new Map()
+const promiseCache = new Map<string, Promise<Response>>()
 
 const createRequestParams = (): RequestInit => {
   return {
@@ -30,7 +30,7 @@ export const getDedupedResponse = async (timestamp: number, url: string): Promis
   const key = `${timestamp}_${url}`
 
   if (promiseCache.has(key)) {
-    return promiseCache.get(key)
+    return promiseCache.get(key)!
   }
 
   const request = new Request(url, createRequestParams())

src/http/server.ts

@@ -14,7 +14,7 @@ const mimeTypes = new Map<string, string>([
   ['.png', 'image/png'],
 ])
 
-export const httpRequestHandler: RequestListener = async (req: IncomingMessage, res: ServerResponse) => {
+export const httpRequestHandler: RequestListener = (req: IncomingMessage, res: ServerResponse) => {
   const filePath = resolveFilePath(req.url)
 
   // Serve 404 if file doesn't exist
@@ -28,7 +28,10 @@ export const httpRequestHandler: RequestListener = async (req: IncomingMessage,
   const extension = path.extname(filePath).toLowerCase()
   const mimeType = mimeTypes.get(extension)
 
-  await serveStaticFile(filePath, mimeType, res)
+  // RequestListener returns void so we must wrap awaits
+  void (async () => {
+    await serveStaticFile(filePath, mimeType, res)
+  })()
 }
 
 const resolveFilePath = (reqUrl: string | undefined): string => {

src/modbus/register.ts

@@ -67,11 +67,11 @@ export const parseRegisterDefinition = (definition: string): ModbusRegister => {
   }
 
   if (!isValidDataType(dataType)) {
-    throw new Error(`Invalid data type specified: ${dataType}`)
+    throw new Error(`Invalid data type specified: ${dataType as string}`)
   }
 
   return {
-    registerType: registerType as RegisterType,
+    registerType,
     address: parsedAddress,
     dataType,
   }

src/publisher.ts

@@ -8,8 +8,8 @@ export enum PublisherType {
 }
 
 export interface PublisherImpl {
-  publishSensorData: (sensorData: PowerSensorData[]) => void
-  publishCharacteristicsSensorData: (sensorData: CharacteristicsSensorData[]) => void
+  publishSensorData: (sensorData: PowerSensorData[]) => Promise<void>
+  publishCharacteristicsSensorData: (sensorData: CharacteristicsSensorData[]) => Promise<void>
 }
 
 export interface Publisher {

src/publisher/console.ts

@@ -9,13 +9,13 @@ export interface ConsolePublisher extends Publisher {
 const logger = createLogger('publisher.console')
 
 export class ConsolePublisherImpl implements PublisherImpl {
-  publishSensorData(sensorData: PowerSensorData[]): void {
+  async publishSensorData(sensorData: PowerSensorData[]): Promise<void> {
     for (const data of sensorData) {
       logger.info(`${data.circuit.name}: ${data.power}W`)
     }
   }
 
-  publishCharacteristicsSensorData(sensorData: CharacteristicsSensorData[]): void {
+  async publishCharacteristicsSensorData(sensorData: CharacteristicsSensorData[]): Promise<void> {
     for (const data of sensorData) {
       logger.info(`${data.characteristics.name}: ${data.voltage}V, ${data.frequency}Hz`)
     }

src/publisher/websocket.ts

@@ -30,7 +30,7 @@ export class WebSocketPublisherImpl implements PublisherImpl {
     // Reuse the HTTP server given to us
     this.wss = new WebSocketServer({ server: httpServer })
 
-    // Keep track of the last published sensor data so we can deliver it immediately (if available) to newly connected
+    // Keep track of the last published sensor data, so we can deliver it immediately (if available) to newly connected
     // clients
     this.lastPublishedSensorData = {
       characteristicsSensorData: null,
@@ -62,7 +62,7 @@ export class WebSocketPublisherImpl implements PublisherImpl {
     })
   }
 
-  publishCharacteristicsSensorData(sensorData: CharacteristicsSensorData[]): void {
+  async publishCharacteristicsSensorData(sensorData: CharacteristicsSensorData[]): Promise<void> {
     this.broadcastMessage({
       type: 'characteristicsSensorData',
       data: sensorData,
@@ -71,7 +71,7 @@ export class WebSocketPublisherImpl implements PublisherImpl {
     this.lastPublishedSensorData.characteristicsSensorData = sensorData
   }
 
-  publishSensorData(sensorData: PowerSensorData[]): void {
+  async publishSensorData(sensorData: PowerSensorData[]): Promise<void> {
     // Remove circular references so we can encode as JSON
     sensorData = untangleCircularDeps(sensorData)
 

src/sensor/modbus.ts

@@ -60,13 +60,13 @@ const readRegisters = async (
 
   switch (register.registerType) {
     case RegisterType.HOLDING_REGISTER:
-      return await client.readHoldingRegisters(address, length)
+      return client.readHoldingRegisters(address, length)
     case RegisterType.INPUT_REGISTER:
-      return await client.readInputRegisters(address, length)
+      return client.readInputRegisters(address, length)
     case RegisterType.COIL:
-      return await client.readCoils(address, length)
+      return client.readCoils(address, length)
     case RegisterType.DISCRETE_INPUT:
-      return await client.readDiscreteInputs(address, length)
+      return client.readDiscreteInputs(address, length)
   }
 }