noInvalidFetchOptions (JavaScript)

Language JavaScript (and super languages)

Summary

Diagnostic Category: lint/nursery/noInvalidFetchOptions
This rule doesn’t have a fix.
The default severity of this rule is error.
Sources:
- Inspired from unicorn/no-invalid-fetch-options

How to configure

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{
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  "linter": {
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    "rules": {
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      "nursery": {
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        "noInvalidFetchOptions": "error"
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      }
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    }
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  }
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}

Description

Disallow a request body in fetch() and new Request() when the method is GET or HEAD.

fetch() and new Request() throw a TypeError when the options contain a body and the method is GET or HEAD. When the options don’t contain a method, the request uses GET.

The rule checks options written as an object directly in the call. It reports a method only when its value is known without running the code, for example a string, or a const variable that holds a string. A body set to undefined or null counts as no body. A spread, such as ...options, placed after body or method can replace them, so the rule doesn’t check those options.

Examples

Invalid

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await fetch("/", { body: "foo=bar" });

code-block.js:1:20 lint/nursery/noInvalidFetchOptions ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This request has a body, but its method is GET.
  
  > 1 │ await fetch("/", { body: "foo=bar" });
      │                    ^^^^
    2 │ 
  
  ℹ Requests that use the GET or HEAD method can't have a body, so this code throws a TypeError when it runs. A request without a method uses GET.
  
  ℹ Remove the body, or use a method that allows one, such as POST.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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new Request("/", { method: "GET", body: "foo=bar" });

code-block.js:1:35 lint/nursery/noInvalidFetchOptions ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This request has a body, but its method is GET.
  
  > 1 │ new Request("/", { method: "GET", body: "foo=bar" });
      │                                   ^^^^
    2 │ 
  
  ℹ Requests that use the GET or HEAD method can't have a body, so this code throws a TypeError when it runs. A request without a method uses GET.
  
  ℹ Remove the body, or use a method that allows one, such as POST.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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await fetch("/", { method: "HEAD", body: "foo=bar" });

code-block.js:1:36 lint/nursery/noInvalidFetchOptions ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This request has a body, but its method is HEAD.
  
  > 1 │ await fetch("/", { method: "HEAD", body: "foo=bar" });
      │                                    ^^^^
    2 │ 
  
  ℹ Requests that use the GET or HEAD method can't have a body, so this code throws a TypeError when it runs. A request without a method uses GET.
  
  ℹ Remove the body, or use a method that allows one, such as POST.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

Valid

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await fetch("/", { method: "HEAD" });
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await fetch("/", { method: "POST", body: "foo=bar" });
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new Request("/", { method: "POST", body: "foo=bar" });
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await fetch("/", { body: undefined });