Saved code change is not hot reloaded

[Michael-Xie]

Bug Report

Current Behavior

I have a lambda that returns a response by providing a POST request with specific parameters in the body. When I make a small code change, like renaming a variable or calculation within one line, the change won't be in effect when I invoke the lambda.

Sample Code

• file: serverless.ts

const serverlessConfiguration: AWS = {
    service: 'portal-lambda',
    frameworkVersion: '3',

    custom: {
        webpack: {
            webpackConfig: './webpack.config.js',
            includeModules: true,
        },
    },
    plugins: ['serverless-webpack', 'serverless-offline'],
    provider: {
        name: 'aws',
        runtime: 'nodejs16.x',
        timeout: 30,

        vpc: {
            securityGroupIds: ['${file(./secrets.json):SECURITY_GROUP}'],
            subnetIds: [
                '${file(./secrets.json):SUBNET1}',
                '${file(./secrets.json):SUBNET2}',
            ],
        },
        apiGateway: {
            minimumCompressionSize: 1024,
            shouldStartNameWithService: true,
        },
        environment: {
                    // key value pairs of env variables
        },
    },
    // import the function via paths
    functions: {
        // functions
    },
    resources: {
        // resources
    },
};

• file: tsconfig.json

{
    "extends": "./tsconfig.paths.json",
    "compilerOptions": {
        "lib": ["ESNext"],
        "moduleResolution": "node",
        "noUnusedLocals": true,
        "noUnusedParameters": true,
        "removeComments": true,
        "sourceMap": true,
        "target": "ES2020",
        "outDir": "lib",
        "esModuleInterop": true
    },
    "include": ["src/**/*.ts", "serverless.ts"],
    "exclude": [
        "node_modules/**/*",
        ".serverless/**/*",
        ".webpack/**/*",
        "_warmup/**/*",
        ".vscode/**/*"
    ],
    "ts-node": {
        "require": ["tsconfig-paths/register"]
    }
}

• file: tsconfig.paths.json

{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "@functions/*": ["src/functions/*"],
      "@libs/*": ["src/libs/*"]
    }
  }
}

Expected behavior/code

I expect the saved code changes can be observed the next time I invoke the function containing them. Now, I have to restart sls offline to see the changes.

Environment

• "serverless": "^3.25.0",

• "serverless-offline": "^11.5.0",

• "@serverless/typescript": "^3.21.0",

• "@shelf/jest-mongodb": "^4.1.3",

• "@types/aws-lambda": "^8.10.108",

• "@types/jest": "^29.2.3",

• "@types/node": "^18.11.9",

• "@typescript-eslint/eslint-plugin": "^5.44.0",

• "@typescript-eslint/parser": "^5.44.0",

• "cz-conventional-changelog": "^3.3.0",

• "eslint": "^8.28.0",

• "eslint-config-prettier": "^8.5.0",

• "eslint-plugin-prettier": "^4.2.1",

• "husky": "^8.0.2",

• "jest": "^29.3.1",

• "json-schema-to-ts": "^2.6.1",

• "lint-staged": "^13.0.3",

• "prettier": "^2.7.1",

• "pretty-quick": "^3.1.3",

• "serverless": "^3.25.0",

• "serverless-webpack": "^5.11.0",

• "standard-version": "^9.5.0",

• "ts-jest": "^29.0.3",

• "ts-loader": "^9.4.1",

• "ts-node": "^10.9.1",

• "tsconfig-paths": "^4.1.0",

• "tsconfig-paths-webpack-plugin": "^4.0.0",

• "typescript": "^4.9.3",

• "webpack": "^5.75.0",

• "webpack-node-externals": "^3.0.0"

• node.js version: v16.17.0

• OS: Ubuntu 19.04

[terozio]

Noticed the same behaviour when I upgraded one older function from serverless-offline 8.8.x to 12.0.x

[Michael-Xie]

Noticed the same behaviour when I upgraded one older function from serverless-offline 8.8.x to 12.0.x

This issue occurred when I finished updating my packages too.

[NickParks]

Same issue here after updating

[IsaaX]

Use the reloadHandler flag.

I personally not sure what the considerations are around the flag but I'd prefer this to be enabled by default?

Just an FYI i'm also using serverless-webpack so that might why there's additional config reloadHandler

[robin-glimp]

Use the reloadHandler flag.

I'm using serverless-esbuild and this works in my case as well 🎉 ! Just sometimes I need to call the API 2 times for the reload to trigger.

To be clear I am starting the serverless-offline cli service with this command now:

• sls offline start --reloadHandler

Note! It does make the API call significantly slower: I have a function that scans a small DynamoDB table and returns the filtered results. This takes ~230ms for each call using the reloadHandler flag. If I dont use that flag it takes ~25ms on subsequent calls. But this tradeoff is so much worth it for being able to hot reload the code!

[terozio]

Use the reloadHandler flag.

Thanks! Missed that one in the release notes.

[Michael-Xie]

Use the reloadHandler flag.

I'm using serverless-esbuild and this works in my case as well tada ! Just sometimes I need to call the API 2 times for the reload to trigger.

To be clear I am starting the serverless-offline cli service with this command now:

• sls offline start --reloadHandler

Note! It does make the API call significantly slower: I have a function that scans a small DynamoDB table and returns the filtered results. This takes ~230ms for each call using the reloadHandler flag. If I dont use that flag it takes ~25ms on subsequent calls. But this tradeoff is so much worth it for being able to hot reload the code!

Thanks this worked~! :+1: