no-shadow.md

pageClass	sidebarDepth	title	description
rule-details	0	svelte/@typescript-eslint/no-shadow	Disallow variable declarations from shadowing variables declared in the outer scope

svelte/@typescript-eslint/no-shadow

Disallow variable declarations from shadowing variables declared in the outer scope

• ❗ This rule has not been released yet.

📖 Rule Details

This rule reports shadowed variables, similar to the base ESLint @typescript-eslint/no-shadow rule. However, it ignores cases where {#snippet} is used as a named slot in Svelte components. If this rule is active, make sure to disable the base @typescript-eslint/no-shadow and svelte/no-shadow and no-shadow rule, as it will conflict with this rule.

<script lang="ts">
  /* eslint svelte/@typescript-eslint/no-shadow: "error" */
  import ComponentWithSnippet from './ComponentWithSnippet.svelte';
</script>

<!-- ✓ GOOD -->
<ComponentWithSnippet>
  {#snippet children()}
    <AnotherComponentWithSnippet>
      {#snippet children()}
        Hello!
      {/snippet}
    </AnotherComponentWithSnippet>
  {/snippet}
</ComponentWithSnippet>
<!-- ✗ BAD -->
<ComponentWithSnippet>
  {@const foo = 1}
  <ComponentWithSnippet>
    {@const foo = 2}
  </ComponentWithSnippet>
</ComponentWithSnippet>

🔧 Options

{
  "svelte/no-shadow": [
    "error",
    { "builtinGlobals": false, "hoist": "functions", "allow": [], "ignoreOnInitialization": false }
  ]
}

• builtinGlobals: The builtinGlobals option is false by default. If it is true, the rule prevents shadowing of built-in global variables: Object, Array, Number, and so on.
• hoist: The hoist option has three settings:
  • functions (by default) - reports shadowing before the outer functions are defined.
  • all - reports all shadowing before the outer variables/functions are defined.
  • never - never report shadowing before the outer variables/functions are defined.
• allow: The allow option is an array of identifier names for which shadowing is allowed. For example, "resolve", "reject", "done", "cb".
• ignoreOnInitialization: The ignoreOnInitialization option is false by default. If it is true, it prevents reporting shadowing of variables in their initializers when the shadowed variable is presumably still uninitialized. The shadowed variable must be on the left side. The shadowing variable must be on the right side and declared in a callback function or in an IIFE.
• ignoreTypeValueShadow: Whether to ignore types named the same as a variable. Default: true. This is generally safe because you cannot use variables in type locations without a typeof operator, so there's little risk of confusion.
• ignoreFunctionTypeParameterNameValueShadow: Whether to ignore function parameters named the same as a variable. Default: true. Each of a function type's arguments creates a value variable within the scope of the function type. This is done so that you can reference the type later using the typeof operator.

📚 Further Reading

• See typescript-eslint no-shadow rule for more information about the base rule.

🔍 Implementation

• Rule source
• Test source

^{Taken with ❤️ from ESLint core}