import/namespace Correctness

What it does

Enforces names exist at the time they are dereferenced, when imported as a full namespace (i.e. import * as foo from './foo'; foo.bar(); will report if bar is not exported by ./foo.). Will report at the import declaration if there are no exported names found. Also, will report for computed references (i.e. foo["bar"]()). Reports on assignment to a member of an imported namespace.

Why is this bad?

Dereferencing a name that does not exist can lead to runtime errors and unexpected behavior in your code. It makes the code less reliable and harder to maintain, as it may not be clear which names are valid. This rule helps ensure that all referenced names are defined, improving the clarity and robustness of your code.

Examples

Given

// ./foo.js
export const bar = "I'm bar";

Examples of incorrect code for this rule:

// ./qux.js
import * as foo from "./foo";
foo.notExported(); // Error: notExported is not exported

// Assignment to a member of an imported namespace
foo.bar = "new value"; // Error: bar cannot be reassigned

// Computed reference to a non-existent export
const method = "notExported";
foo[method](); // Error: notExported does not exist

Examples of correct code for this rule:

// ./baz.js
import * as foo from "./foo";
console.log(foo.bar); // Valid: bar is exported

// Computed reference
const method = "bar";
foo[method](); // Valid: method refers to an exported function

References

• Rule Source