SyntaxError: Cannot use import statement outside a module means the JavaScript runtime encountered an import declaration in a file it is treating as a CommonJS script, not an ES module. The runtime refuses to parse import syntax in script mode because modules and scripts have different parsing goals and scoping rules.
This guide covers the 10 most common causes — from a missing "type": "module" in package.json to misconfigured test runners — with a reproduction and fix for each. If your case doesn't match any single cause, use the diagnostic checklist to narrow it down.
| Error | SyntaxError: Cannot use import statement outside a module |
|---|
| Where it happens | JavaScript — Node.js (v12+), browser
이 블로그의 인기 게시물
TypeError: Cannot read properties of undefined (reading 'map') means you called .map() on something that does not exist. JavaScript evaluated the expression to the left of .map , got undefined , and stopped there. The distinction that matters: the array is not empty, it is absent . An empty array maps fine and renders nothing. undefined has no properties at all, so the property lookup itself throws before your callback ever runs. Older JavaScript engines print the same failure as Cannot read property 'map' of undefined . Same bug, older wording - everything on this page applies. Below: the one-line fix, then 11 distinct causes with a reproduction and a fix for each, then a checklist for when your case matches none of them. Error TypeError: Cannot read properties of undefined (reading 'map') Where it happens JavaScript - browser or Node.js, any framework. Most often React or Vue rendering a list from data that has not arrived, or a server response wh...
What npm Is Actually Telling You npm ERR! code ERESOLVE unable to resolve dependency tree means npm found a peer dependency conflict it refuses to guess its way out of. Two packages in your tree each demand a version of the same dependency, and those demands do not overlap. It is not a network error, a corrupt cache, or a broken npm install. The tree you asked for is genuinely unsatisfiable as written. The reason this appeared in projects that installed fine for years is that npm 7 started enforcing peer dependencies instead of silently ignoring them. Nothing about your project got worse; the check got stricter. Below are the nine situations that produce it, most common first, with the fix for each and how to confirm it worked. Error npm ERR! code ERESOLVE npm ERR! ERESOLVE unable to resolve dependency tree npm ERR! While resolving: my-app@1.0.0 npm ERR! Found: react@18.2.0 npm ERR! Could not resolve dependency: npm ERR! peer react@"^17.0.0" from some-package@3.1....
Error: ERR_MODULE_NOT_FOUND: Cannot find package fires when Node.js resolves an import or require() and the target package does not exist on any search path. The runtime tried every directory in the module resolution chain and came up empty. This page covers 10 distinct causes — from a missing npm install to subtle ESM resolution rules — with a reproduction and fix for each. A diagnostic checklist at the end helps you narrow down cases that don't fit a single cause cleanly. If you are in a hurry, the TL;DR fix below handles the majority of occurrences in one command. Error Error [ERR_MODULE_NOT_FOUND]: Cannot find package ' ' imported from /path/to/your/file.mjs Where it happens Node.js (v12.17+ with ES modules, or v14+ with --experimental-specifier-resolution). Appears in any framework that runs on Node: Next.js, Nuxt, Remix, plain scripts. What it means Node's module resolver walked every candidate directory for the package you imported and found noth...
|
|---|
