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feat(linter): implement unicorn/prefer-global-this (#11197)
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‎crates/oxc_linter/src/rules.rs‎

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@@ -400,6 +400,7 @@ mod unicorn {
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pub mod prefer_dom_node_remove;
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pub mod prefer_dom_node_text_content;
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pub mod prefer_event_target;
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pub mod prefer_global_this;
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pub mod prefer_includes;
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pub mod prefer_logical_operator_over_ternary;
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pub mod prefer_math_min_max;
@@ -1037,6 +1038,7 @@ oxc_macros::declare_all_lint_rules! {
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unicorn::no_zero_fractions,
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unicorn::number_literal_case,
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unicorn::numeric_separators_style,
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unicorn::prefer_global_this,
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unicorn::prefer_object_from_entries,
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unicorn::prefer_array_find,
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unicorn::prefer_array_index_of,

‎crates/oxc_linter/src/rules/unicorn/prefer_global_this.rs‎

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@@ -0,0 +1,382 @@
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use oxc_ast::{
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AstKind,
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ast::{Expression, MemberExpression},
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};
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use oxc_diagnostics::OxcDiagnostic;
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use oxc_macros::declare_oxc_lint;
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use oxc_span::{GetSpan, Span};
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use crate::{AstNode, context::LintContext, rule::Rule};
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fn prefer_global_this_diagnostic(span: Span) -> OxcDiagnostic {
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OxcDiagnostic::warn("Prefer `globalThis` over environment-specific global aliases like `window`, `self`, and `global`.")
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.with_help("Replace the alias with `globalThis`.")
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.with_label(span)
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}
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#[derive(Debug, Default, Clone)]
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pub struct PreferGlobalThis;
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declare_oxc_lint!(
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/// ### What it does
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///
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/// Enforces the use of [`globalThis`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/globalThis) instead of
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/// environment‑specific global object aliases (`window`, `self`, or `global`).
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/// Using the standard `globalThis` makes your code portable across browsers, Web Workers, Node.js,
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/// and future JavaScript runtimes.
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///
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/// ### Why is this bad?
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///
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/// • **Portability** – `window` is only defined in browser main threads, `self` is used in Web Workers,
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/// and `global` is Node‑specific. Choosing the wrong alias causes runtime crashes when the code is
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/// executed outside of its original environment.
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/// • **Clarity** – `globalThis` clearly communicates that you are referring to the global object itself
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/// rather than a particular platform.
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///
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/// ### Examples
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///
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/// Examples of **incorrect** code for this rule:
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/// ```js
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/// // Browser‑only
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/// window.alert("Hi");
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///
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/// // Node‑only
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/// if (typeof global.Buffer !== "undefined") {}
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///
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/// // Web Worker‑only
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/// self.postMessage("done");
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/// ```
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///
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/// Examples of **correct** code for this rule:
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/// ```js
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/// globalThis.alert("Hi");
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///
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/// if (typeof globalThis.Buffer !== "undefined") {}
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///
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/// globalThis.postMessage("done");
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/// ```
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PreferGlobalThis,
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unicorn,
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style,
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pending
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);
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impl Rule for PreferGlobalThis {
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fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
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let AstKind::IdentifierReference(ident) = node.kind() else { return };
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if !matches!(ident.name.as_str(), "window" | "self" | "global")
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|| is_computed_member_expression_object(node, ctx)
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|| !ctx.scoping().root_unresolved_references().contains_key(&ident.name.as_str())
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{
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return;
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}
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if let Some(AstKind::MemberExpression(MemberExpression::StaticMemberExpression(e))) =
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ctx.nodes().parent_kind(node.id())
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{
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if let Expression::Identifier(ident) = &e.object {
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if ident.name == "self"
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&& WEB_WORKER_SPECIFIC_APIS.contains(&e.property.name.as_str())
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{
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return;
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}
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if ident.name == "window"
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&& WINDOW_SPECIFIC_APIS.contains(&e.property.name.as_str())
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{
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if matches!(
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e.property.name.as_str(),
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"addEventListener" | "removeEventListener" | "dispatchEvent"
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) {
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if let Some(AstKind::CallExpression(call_expr)) =
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ctx.nodes().ancestor_kinds(node.id()).nth(2)
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{
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if let Some(Expression::StringLiteral(lit)) =
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call_expr.arguments.first().and_then(|arg| arg.as_expression())
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{
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if WINDOW_SPECIFIC_EVENTS.contains(&lit.value.as_str()) {
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return;
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}
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}
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} else {
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return;
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}
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} else {
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return;
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}
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}
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}
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}
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ctx.diagnostic(prefer_global_this_diagnostic(ident.span));
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}
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}
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/// `window[foo]`, `self[bar]`, etc. are allowed.
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fn is_computed_member_expression_object(node: &AstNode<'_>, ctx: &LintContext<'_>) -> bool {
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if let Some(AstKind::MemberExpression(member_expr)) = ctx.nodes().parent_kind(node.id()) {
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if !member_expr.is_computed() {
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return false;
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}
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if let Expression::Identifier(obj_ident) = &member_expr.object().get_inner_expression() {
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return obj_ident.span == node.kind().span();
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}
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}
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false
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}
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const WEB_WORKER_SPECIFIC_APIS: &[&str] = &[
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// https://html.spec.whatwg.org/multipage/workers.html#the-workerglobalscope-common-interface
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"addEventListener",
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"removeEventListener",
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"dispatchEvent",
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"self",
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"location",
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"navigator",
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"onerror",
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"onlanguagechange",
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"onoffline",
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"ononline",
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"onrejectionhandled",
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"onunhandledrejection",
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// https://html.spec.whatwg.org/multipage/workers.html#dedicated-workers-and-the-dedicatedworkerglobalscope-interface
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"name",
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"postMessage",
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"onconnect",
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];
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const WINDOW_SPECIFIC_APIS: &[&str] = &[
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// Properties and methods
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// https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-window-object
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"name",
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"locationbar",
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"menubar",
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"personalbar",
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"scrollbars",
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"statusbar",
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"toolbar",
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"status",
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"close",
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"closed",
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"stop",
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"focus",
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"blur",
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"frames",
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"length",
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"top",
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"opener",
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"parent",
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"frameElement",
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"open",
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"originAgentCluster",
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"postMessage",
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// Events commonly associated with "window"
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"onresize",
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"onblur",
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"onfocus",
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"onload",
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"onscroll",
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"onscrollend",
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"onwheel",
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"onbeforeunload",
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"onmessage",
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"onmessageerror",
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"onpagehide",
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"onpagereveal",
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"onpageshow",
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"onpageswap",
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"onunload",
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// To add/remove/dispatch events that are commonly associated with "window"
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// https://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-flow
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"addEventListener",
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"removeEventListener",
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"dispatchEvent",
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// https://dom.spec.whatwg.org/#idl-index
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"event", // Deprecated and quirky, best left untouched
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// https://drafts.csswg.org/cssom-view/#idl-index
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"screen",
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"visualViewport",
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"moveTo",
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"moveBy",
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"resizeTo",
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"resizeBy",
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"innerWidth",
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"innerHeight",
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"outerWidth",
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"outerHeight",
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"scrollX",
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"pageXOffset",
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"scrollY",
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"pageYOffset",
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"scroll",
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"scrollTo",
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"scrollBy",
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"screenX",
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"screenLeft",
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"screenY",
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"screenTop",
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"screenWidth",
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"screenHeight",
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"devicePixelRatio",
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];
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// Allow `on<event>` where <event> is in the windowSpecificEvents set from reference implementation.
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const WINDOW_SPECIFIC_EVENTS: &[&str] = &[
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"resize",
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"blur",
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"focus",
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"load",
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"scroll",
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"scrollend",
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"wheel",
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"beforeunload",
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"message",
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"messageerror",
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"pagehide",
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"pagereveal",
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"pageshow",
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"pageswap",
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"unload",
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];
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#[test]
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fn test() {
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use crate::tester::Tester;
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let pass = vec![
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"globalThis",
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"globalThis.foo",
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"globalThis[foo]",
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"globalThis.foo()",
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"const { foo } = globalThis",
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"function foo (window) {}",
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"function foo (global) {}",
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"var foo = function foo (window) {}",
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"var foo = function foo (global) {}",
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"var window = {}",
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"let global = {}",
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"const global = {}",
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"function foo (window) {
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window.foo();
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}",
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"var window = {};
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function foo () {
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window.foo();
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}",
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"foo.window",
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"foo.global",
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r#"import window from "xxx""#,
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r#"import * as window from "xxx""#,
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r#"import window, {foo} from "xxx""#,
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r#"export { window } from "xxx""#,
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r#"export * as window from "xxx";"#,
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"try {
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} catch (window) {}",
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r#"window.name = "foo""#,
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"window.addEventListener",
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"window.innerWidth",
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"window.innerHeight",
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"self.location",
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"self.navigator",
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r#"window.addEventListener("resize", () => {})"#,
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"window.onresize = function () {}",
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"const {window} = jsdom()
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window.jQuery = jQuery;",
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"({ foo: window.name } = {})",
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"[window.name] = []",
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"window[foo]",
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"window[title]",
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r#"window["foo"]"#,
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];
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let fail = vec![
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"global",
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"self",
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"window",
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"window.foo",
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"window.foo()",
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"window > 10",
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"10 > window",
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"window ?? 10",
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"10 ?? window",
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"window.foo = 123",
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"window = 123",
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"obj.a = window",
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"function* gen() {
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yield window
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}",
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"async function gen() {
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await window
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}",
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"window ? foo : bar",
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"foo ? window : bar",
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"foo ? bar : window",
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"function foo() {
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return window
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}",
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"new window()",
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"const obj = {
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foo: window.foo,
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bar: window.bar,
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window: window
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}",
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"function sequenceTest() {
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let x, y;
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x = (y = 10, y + 5, window);
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console.log(x, y);
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}",
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"window`Hello ${42} World`",
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"tag`Hello ${window.foo} World`",
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"var str = `hello ${window.foo} world!`",
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"delete window.foo",
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"++window",
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"++window.foo",
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"for (var attr in window) {
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}",
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"for (window.foo = 0; i < 10; window.foo++) {
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}",
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"for (const item of window.foo) {
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}",
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"for (const item of window) {
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}",
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"switch (window) {}",
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"switch (true) {
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case window:
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break;
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}",
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"switch (true) {
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case window.foo:
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break;
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}",
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"while (window) {
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}",
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"do {} while (window) {}",
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"if (window) {}",
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"throw window",
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"var foo = window",
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"function foo (name = window) {
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}",
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"self.innerWidth",
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"self.innerHeight",
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"window.crypto",
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r#"window.addEventListener("play", () => {})"#,
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"window.onplay = function () {}",
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"function greet({ name = window.foo }) {}",
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"({ foo: window.foo } = {})",
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"[window.foo] = []",
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"foo[window]",
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"foo[window.foo]",
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r#"typeof window !== "undefined""#,
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r#"typeof self !== "undefined""#,
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r#"typeof global !== "undefined""#,
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r#"typeof window.something === "function""#,
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r#"typeof self.something === "function""#,
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r#"typeof global.something === "function""#,
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"global.global_did_not_declare_in_language_options",
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"window.window_did_not_declare_in_language_options",
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"self.self_did_not_declare_in_language_options",
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];
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Tester::new(PreferGlobalThis::NAME, PreferGlobalThis::PLUGIN, pass, fail).test_and_snapshot();
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}

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