TypeScript noteworthy notes

The moment you start focusing on yourself, things start falling into place.

TypeScript Errors

Cannot use import statement outside a module

When import a module, getting

import generateMsg from '@ovotech/avro-mock-generator'
(node:33073) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
/Users/todzhang/dev/workspace/avro-mock-generator/todd.js:1
import generateMsg from '@ovotech/avro-mock-generator'
^^^^^^

SyntaxError: Cannot use import statement outside a module
    at Object.compileFunction (node:vm:352:18)
    at wrapSafe (node:internal/modules/cjs/loader:1026:15)
    at Module._compile (node:internal/modules/cjs/loader:1061:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1151:10)
    at Module.load (node:internal/modules/cjs/loader:975:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:77:12)
    at node:internal/main/run_main_module:17:47

Solutions

To solve this issue, in your package.json file, add "type": "module" in the upper level as show below:

{
  "name": "my-app",
  "version": "0.0.0",
  "type": "module",
  "scripts": { ...
  },

Error: Cannot find package

node:internal/errors:465
    ErrorCaptureStackTrace(err);
    ^

Error [ERR_MODULE_NOT_FOUND]: Cannot find package '@ovotech/avro-mock-generator' imported from /Users/todzhang/dev/workspace/avro-mock-generator/todd.js
    at new NodeError (node:internal/errors:372:5)
    at packageResolve (node:internal/modules/esm/resolve:901:9)
    at moduleResolve (node:internal/modules/esm/resolve:950:20)
    at defaultResolve (node:internal/modules/esm/resolve:1166:11)
    at ESMLoader.resolve (node:internal/modules/esm/loader:536:30)
    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:250:18)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:79:40)
    at link (node:internal/modules/esm/module_job:78:36) {
  code: 'ERR_MODULE_NOT_FOUND'
}

Solutions

To install the library

npm i --save-dev @ovotech/avro-mock-generator

Error: xx is not a function

TypeError: generate is not a function

Async Await keywords

Async Await Support in TypeScript Async - Await has been supported by TypeScript since version 1.7. Asynchronous functions are prefixed with the async keyword; await suspends the execution until an asynchronous function return promise is fulfilled and unwraps the value from the Promise returned. It was only supported for target es6 transpiling directly to ES6 generators.

Troubleshooting

Unexpected token …

That’s because your node version is lower (e.g. node v4.x), which don’t support spread operator. You’d firstly check your node version

node -v

If above result say node is v4.x, then you should run following commands to upgrade your node. Normally you can leverage Node Package Manager n as below:

sudo npm install -g n
sudo n stable 

2024

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2023

Az Cli

To run commands in VMs in Azure

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2022

Minium Workable Mvp Vimrc

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Linux Tips

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How to user fire extinguisher

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2020

Debug Stuck IntelliJ

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2019

Conversations with God

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Foreign Exchange

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Guice

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NodeJs Notes

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R Language

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