Find Import File without Extension

• Playground Link

Description

In ECMAScript modules (ESM), the module specifier must include the file extension, such as .js or .mjs, when importing local or absolute modules. This is because ESM does not perform any automatic file extension resolution, unlike CommonJS modules tools such as Webpack or Babel. This behavior matches how import behaves in browser environments, and is specified by the ESM module spec.

The rule finds all imports (static and dynamic) for files without a file extension.

YAML

id: find-import-file
language: js
rule:
  regex: "/[^.]+[^/]$"
  kind: string_fragment
  any:
    - inside:
        stopBy: end
        kind: import_statement
    - inside:
        stopBy: end
        kind: call_expression
        has:
          field: function
          regex: "^import$"

Example

import a, {b, c, d} from "./file";
import e from "./other_file.js";
import "./folder/";
import {x} from "package";
import {y} from "package/with/path";

import("./dynamic1");
import("./dynamic2.js");

my_func("./unrelated_path_string")

Contributed by

DasSurma in this tweet.