No Shared Type Import

Enforce type layering by preventing code files from importing shared type files directly. Shared types should only be imported by .d.ts files.

Summary

The no-shared-type-import rule reports imports from shared type files (e.g., shared.d.ts) when the importing file is not a .d.ts file. This enforces a layered type architecture where shared types flow through domain .d.ts files before reaching code files.

Why Use This Rule?

1. Enforces a clean type hierarchy: shared.d.ts to domain .d.ts to .ts code.
2. Prevents code files from depending on low-level shared types directly.
3. Makes refactoring safer because shared type changes only propagate through domain type files.

Examples

Correct

// In a .d.ts file — importing shared types is allowed.
// types/cli/runner.d.ts
import type { EntryCategory } from '@/types/shared.d.ts';
export type RunnerRecordSelectedCategory = EntryCategory;

// In a .ts code file — import from the domain .d.ts file.
// cli/runner.ts
import type { RunnerRecordSelectedCategory } from '@/types/cli/runner.d.ts';

Incorrect

// In a .ts code file — importing shared types directly.
// cli/runner.ts
import type { EntryCategory } from '@/types/shared.d.ts';

Configuration

Enable the rule in your ESLint flat config:

import { noSharedTypeImport } from '@cbnventures/nova/rules/eslint';

export default [
  {
    plugins: {
      '@cbnventures/nova': {
        rules: {
          'no-shared-type-import': noSharedTypeImport,
        },
      },
    },
    rules: {
      '@cbnventures/nova/no-shared-type-import': ['error', {
        sharedFiles: ['shared.d.ts'],
      }],
    },
  },
];

Options

Option	Type	Default	Description
sharedFiles	string[]	[]	File paths or suffixes that identify shared type files (e.g., ['shared.d.ts']).

Each entry in sharedFiles is matched against the end of the import source path. For example, 'shared.d.ts' matches any import whose source ends with /shared.d.ts.

Troubleshooting

• Error fires on a .d.ts file. — The rule skips .d.ts files entirely. If the file is a .d.ts but the error still fires, check that the filename extension is correct.
• Want to allow multiple shared files. — Add each shared file path to the sharedFiles array (e.g., ['shared.d.ts', 'common.d.ts']).