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💅 False positive lint/nursery/useExplicitType on module-level assignment when RHS is not a constant #5932

@sterliakov

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@sterliakov

Environment information

CLI:
  Version:                      2.0.0-beta.2
  Color support:                true

Platform:
  CPU Architecture:             x86_64
  OS:                           linux

Environment:
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  NO_COLOR:                     unset
  TERM:                         xterm-256color
  JS_RUNTIME_VERSION:           v20.18.0
  JS_RUNTIME_NAME:              node
  NODE_PACKAGE_MANAGER:         npm/10.8.2

Biome Configuration:
  Status:                       Loaded successfully
  Path:                         /home/stas/Documents/Work/simpleem-fe/biome.jsonc
  Formatter enabled:            true
  Linter enabled:               true
  Assist enabled:               true
  VCS enabled:                  false

Linter:
  JavaScript enabled:           unset
  JSON enabled:                 unset
  CSS enabled:                  unset
  GraphQL enabled:              unset
  Recommended:                  true
  Enabled rules:
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Workspace:
  Open Documents:               0

Rule name

lint/nursery/useExplicitType

Playground link

https://next.biomejs.dev/playground/?indentStyle=space&indentWidth=4&lintRules=all&enabledAssist=false&code=YwBvAG4AcwB0ACAAZgBvAG8AOgAgAHMAdAByAGkAbgBnACAAfAAgAG4AdQBsAGwAIAA9ACAAbABvAGMAYQBsAFMAdABvAHIAYQBnAGUALgBnAGUAdABJAHQAZQBtACgAIgBmAG8AbwAiACkAOwAKAA%3D%3D&language=ts

Inline reproducer:

const foo: string | null = localStorage.getItem("foo");
// lint/nursery/useExplicitType: The variable doesn't have a type defined.

Expected result

No error, the variable is explicitly annotated with a type.

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A-LinterArea: linterL-JavaScriptLanguage: JavaScript and super languagesS-Bug-confirmedStatus: report has been confirmed as a valid bug

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