fix(linter/consistent-indexed-object-style): skip fixing default exported interface

[Copilot]

The consistent-indexed-object-style rule was generating invalid TypeScript when converting export default interface with index signatures. TypeScript does not allow export default type, causing the autofix to produce syntax errors.

Changes

• Skip autofix for export default interfaces: Detect when an interface is exported as default and report the diagnostic without providing an autofix
• Preserve autofix for named exports: Ensure export interface declarations still get the correct autofix to export type

Example

// Before: Rule would suggest invalid fix
export default interface SchedulerService {
    [key: string]: unknown;
}
// ❌ Invalid: export default type SchedulerService = Record<string, unknown>;

// After: Rule reports error without autofix
// ✅ Users can manually refactor by removing default export or using named export

// Named exports still work correctly:
export interface Foo {
    [key: string]: unknown;
}
// ✅ Valid fix: export type Foo = Record<string, unknown>;

Original prompt

---

This section details on the original issue you should resolve

<issue_title>linter: Invalid fix for typescript/consistent-indexed-object-style rule</issue_title>
<issue_description>### What version of Oxlint are you using?

unreleased

What command did you run?

No response

What does your .oxlintrc.json config file look like?

N/A

What happened?

See: https://github.com/oxc-project/oxc-ecosystem-ci/actions/runs/20888867135/job/60016741058#step:11:73

I suspect this is due to the changes for consistent-indexed-object-style in #17802

This:

declare module "ember-task-scheduler" {
    export default interface SchedulerService {
        [key: string]: unknown;
    }
}

Becomes:

declare module "ember-task-scheduler" {
    export default type SchedulerService = Record<string, unknown>;
}

And you can't have a default export for a type, apparently.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes linter: Invalid fix for typescript/consistent-indexed-object-style rule #17866

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[codspeed-hq]

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing copilot/fix-linter-invalid-fix (78d65a2) with main (51c2815)}

Summary

✅ 4 untouched benchmarks
⏩ 41 skipped benchmarks¹

Footnotes

1. 41 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[Copilot]

Pull request overview

This PR fixes the consistent-indexed-object-style linter rule to avoid generating invalid TypeScript syntax when attempting to autofix export default interface declarations with index signatures. TypeScript does not allow the syntax export default type, so the rule now skips autofixing for default-exported interfaces while continuing to report the diagnostic.

Changes:

• Skip autofix for export default interface declarations to prevent invalid export default type syntax
• Preserve autofix functionality for named export interface declarations
• Add test cases for both scenarios to ensure correct behavior

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
crates/oxc_linter/src/rules/typescript/consistent_indexed_object_style.rs	Added check to detect ExportDefaultDeclaration parent and skip autofix; added test cases for both export default and named export scenarios
crates/oxc_linter/src/snapshots/typescript_consistent_indexed_object_style.snap	Updated snapshot to include diagnostic output for the export default interface test case

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