Proposal: Enforce Exact Import Path Casing

[jimmywarting]

Add a built-in lint rule that enforces exact casing of import paths to match the filesystem. The rule should be enabled by default and require no configuration.

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Problem

On case-insensitive filesystems (macOS, Windows), import paths that do not match the actual file casing work locally but fail on case-sensitive systems (Linux) at runtime, resulting in 404 errors or module resolution failures.

Example:

import './myComponent.js'

Actual file on disk:

mycomponent.js

This works locally but fails in production. Such errors are silent during development and only appear after deployment.

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Default Behavior

• Enabled by default
• No configuration required

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Rationale

Mismatched import casing is always a cross-platform bug. Enforcing exact casing at lint time prevents deployment failures and ensures consistent behavior across all operating systems.