fix(runtime-handler): add warning for optional context vars (#317)

Author: dkundel

Diff for: packages/runtime-handler/src/dev-runtime/internal/functionRunner.ts

@@ -1,6 +1,11 @@
 import { ServerlessCallback } from '@twilio-labs/serverless-runtime-types/types';
 import { serializeError } from 'serialize-error';
-import { constructContext, constructGlobalScope, isTwiml } from '../route';
+import {
+  augmentContextWithOptionals,
+  constructContext,
+  constructGlobalScope,
+  isTwiml,
+} from '../route';
 import { ServerConfig } from '../types';
 import { Response } from './response';
 import { setRoutes } from './route-cache';
@@ -62,8 +67,9 @@ process.on(
     try {
       setRoutes(config.routes);
       constructGlobalScope(config);
-      const context = constructContext(config, path);
+      let context = constructContext(config, path);
       sendDebugMessage('Context for %s: %p', path, context);
+      context = augmentContextWithOptionals(config, context);
       sendDebugMessage('Event for %s: %o', path, event);
       let run_timings: { start: [number, number]; end: [number, number] } = {
         start: [0, 0],

Diff for: packages/runtime-handler/src/dev-runtime/route.ts

@@ -6,6 +6,7 @@ import {
   TwilioClientOptions,
   TwilioPackage,
 } from '@twilio-labs/serverless-runtime-types/types';
+import chalk from 'chalk';
 import { fork } from 'child_process';
 import {
   NextFunction,
@@ -23,6 +24,7 @@ import * as Runtime from './internal/runtime';
 import { ServerConfig } from './types';
 import debug from './utils/debug';
 import { wrapErrorInHtml } from './utils/error-html';
+import { getCodeLocation } from './utils/getCodeLocation';
 import { requireFromProject } from './utils/requireFromProject';
 import { cleanUpStackTrace } from './utils/stack-trace/clean-up';
 
@@ -39,6 +41,60 @@ export function constructEvent<T extends {} = {}>(req: ExpressRequest): T {
   return { ...req.query, ...req.body };
 }
 
+export function augmentContextWithOptionals(
+  config: ServerConfig,
+  context: Context
+): Context<{
+  ACCOUNT_SID?: string;
+  AUTH_TOKEN?: string;
+  DOMAIN_NAME: string;
+  PATH: string;
+  SERVICE_SID: string | undefined;
+  ENVIRONMENT_SID: string | undefined;
+  [key: string]: string | undefined | Function;
+}> {
+  log('Adding getters with warnings to optional properties');
+  if (typeof context.SERVICE_SID === 'undefined') {
+    let _serviceSid: string | undefined = undefined;
+    Object.defineProperty(context, 'SERVICE_SID', {
+      get: () => {
+        if (_serviceSid === undefined) {
+          console.warn(
+            chalk`{bold.yellow WARNING} at ${getCodeLocation({
+              relativeFrom: config.baseDir,
+              offset: 1,
+            })} The SERVICE_SID variable is undefined by default in local development. This variable will be autopopulated when your Functions get deployed. Learn more at: https://twil.io/toolkit-variables`
+          );
+        }
+        return _serviceSid;
+      },
+      set: (value: string) => {
+        _serviceSid = value;
+      },
+    });
+  }
+  if (typeof context.ENVIRONMENT_SID === 'undefined') {
+    let _environmentSid: string | undefined = undefined;
+    Object.defineProperty(context, 'ENVIRONMENT_SID', {
+      get: () => {
+        if (_environmentSid === undefined) {
+          console.warn(
+            chalk`{bold.yellow WARNING} at ${getCodeLocation({
+              relativeFrom: config.baseDir,
+              offset: 1,
+            })}: The ENVIRONMENT_SID variable is undefined by default in local development. This variable will be autopopulated when your Functions get deployed. Learn more at: https://twil.io/toolkit-variables`
+          );
+        }
+        return _environmentSid;
+      },
+      set: (value: string) => {
+        _environmentSid = value;
+      },
+    });
+  }
+  return context;
+}
+
 export function constructContext<T extends {} = {}>(
   { url, env, logger, baseDir }: ServerConfig,
   functionPath: string
@@ -74,7 +130,15 @@ export function constructContext<T extends {} = {}>(
   }
   const DOMAIN_NAME = url.replace(/^https?:\/\//, '');
   const PATH = functionPath;
-  return { PATH, DOMAIN_NAME, ...env, getTwilioClient };
+  const context = {
+    PATH,
+    DOMAIN_NAME,
+    SERVICE_SID: undefined,
+    ENVIRONMENT_SID: undefined,
+    ...env,
+    getTwilioClient,
+  };
+  return context;
 }
 
 export function constructGlobalScope(config: ServerConfig): void {

Diff for: packages/runtime-handler/src/dev-runtime/utils/getCodeLocation.ts

@@ -0,0 +1,67 @@
+import os from 'os';
+import path from 'path';
+
+export type CodeLocation =
+  | {
+      line: null;
+      filePath: null;
+      column: null;
+      toString(): 'unknown';
+    }
+  | {
+      line: number;
+      column: number;
+      filePath: string;
+      toString(): string;
+    };
+
+export const UNKNOWN_LOCATION = {
+  line: null,
+  filePath: null,
+  column: null,
+  toString: (): 'unknown' => {
+    return 'unknown';
+  },
+};
+
+const STACK_TRACE_REGEX = /.*\((?<fullFilePath>.*):(?<line>\d+):(?<column>\d+)\)$/i;
+
+export function getCodeLocation(
+  options: { relativeFrom?: string; offset?: number } = {}
+): CodeLocation {
+  options = { relativeFrom: undefined, offset: 0, ...options };
+  const fullStackTrace = new Error().stack;
+  if (typeof fullStackTrace !== 'string') {
+    return UNKNOWN_LOCATION;
+  }
+
+  const stackLines = fullStackTrace.split(os.EOL);
+  // add two to the offset because the first line is "Error" and the next is the location of this function.
+  const locationLine = stackLines[(options.offset || 0) + 2];
+
+  if (!locationLine) {
+    return UNKNOWN_LOCATION;
+  }
+
+  const match = STACK_TRACE_REGEX.exec(locationLine);
+  if (match === null) {
+    return UNKNOWN_LOCATION;
+  }
+
+  const line = parseInt(match.groups?.line || '0', 0);
+  const column = parseInt(match.groups?.column || '0', 0);
+  let filePath = match.groups?.fullFilePath || 'unknown';
+
+  if (options.relativeFrom) {
+    filePath = path.relative(options.relativeFrom, filePath);
+  }
+
+  const stringVersion = `${filePath}:${line}:${column}`;
+
+  return {
+    line,
+    column,
+    filePath,
+    toString: () => stringVersion,
+  };
+}

Diff for: packages/serverless-runtime-types/types.d.ts

@@ -46,6 +46,9 @@ export type RuntimeInstance = {
 export type Context<T = {}> = {
   getTwilioClient(options?: TwilioClientOptions): twilio.Twilio;
   DOMAIN_NAME: string;
+  PATH: string;
+  SERVICE_SID: string | undefined;
+  ENVIRONMENT_SID: string | undefined;
 } & T;
 
 export type ServerlessCallback = (

Diff for: packages/twilio-run/package.json

@@ -36,7 +36,7 @@
   "license": "MIT",
   "dependencies": {
     "@twilio-labs/serverless-api": "^5.2.0",
-    "@twilio-labs/serverless-runtime-types": "^2.1.0",
+    "@twilio-labs/serverless-runtime-types": "2.1.0-rc.0",
     "@types/express": "4.17.7",
     "@types/inquirer": "^6.0.3",
     "@types/is-ci": "^2.0.0",