no-esmoduleinterop-with-verbatim

Disallow esModuleInterop: true when verbatimModuleSyntax: true is already configured, because verbatimModuleSyntax supersedes and conflicts with the interop shim model.

Targeted pattern scope

The compilerOptions.esModuleInterop and compilerOptions.verbatimModuleSyntax fields in any tsconfig*.json file.

What this rule reports

This rule reports when both "esModuleInterop": true and "verbatimModuleSyntax": true appear together in compilerOptions.

Why this rule exists

esModuleInterop was introduced to allow writing import React from "react" instead of import * as React from "react" for CJS modules. It works by injecting interop helper functions at emit time.

verbatimModuleSyntax takes a stricter approach: every import and export is emitted exactly as written, with no interop shims. The two options represent fundamentally different mental models of how modules behave. Using both together produces undefined behavior for default imports of CJS modules — verbatimModuleSyntax wins and the esModuleInterop shims are not inserted, potentially causing silent runtime failures if the code relied on synthetic default imports.

Remove esModuleInterop when verbatimModuleSyntax is active, and update any default imports of CJS modules to namespace-style imports.

❌ Incorrect

{
    "compilerOptions": {
        "esModuleInterop": true,
        "verbatimModuleSyntax": true
    }
}

The esModuleInterop shims will not be inserted because verbatimModuleSyntax takes precedence, making the option a dead setting that misleads readers.

✅ Correct

Use verbatimModuleSyntax alone for ESM-first codebases:

{
    "compilerOptions": {
        "verbatimModuleSyntax": true
    }
}

Or use esModuleInterop alone for CJS-interop codebases:

{
    "compilerOptions": {
        "esModuleInterop": true
    }
}

When not to use it

This rule should always be enabled. There is no well-defined scenario where both flags should be active simultaneously.

Package documentation

Rule catalog ID: R007

Targeted pattern scope​

What this rule reports​

Why this rule exists​

❌ Incorrect​

✅ Correct​

When not to use it​

Package documentation​

Further reading​