From 298d3c1e587138cb7d78d9ed84fa06b11b70aa78 Mon Sep 17 00:00:00 2001
From: Michael Giraldo <michael.giraldo@gmail.com>
Date: Mon, 8 Dec 2025 18:15:28 -0800
Subject: [PATCH 1/4] feat(scope-manager): add eslint10 globals opt-in, guard,
 and tests

---
 docs/packages/Scope_Manager.mdx               |  21 ++
 packages/scope-manager/src/ScopeManager.ts    |  98 +++++++++
 packages/scope-manager/src/analyze.ts         |  12 ++
 packages/scope-manager/src/scope/ScopeBase.ts |  35 ++--
 .../eslint-scope/add-globals-extra.test.ts    | 187 ++++++++++++++++++
 .../tests/eslint-scope/add-globals.test.ts    | 136 +++++++++++++
 .../eslint-scope/label-script-default.test.ts |  37 ++++
 .../eslint-scope/module-var-scope.test.ts     |  24 +++
 .../references-script-default.test.ts         |  60 ++++++
 .../script-globals-default-vs-opt-in.test.ts  | 143 ++++++++++++++
 .../script-globals-edge-cases.test.ts         |  77 ++++++++
 .../tests/eslint-scope/script-nested.test.ts  |  57 ++++++
 12 files changed, 873 insertions(+), 14 deletions(-)
 create mode 100644 packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/add-globals.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/label-script-default.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/references-script-default.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts
 create mode 100644 packages/scope-manager/tests/eslint-scope/script-nested.test.ts

diff --git a/docs/packages/Scope_Manager.mdx b/docs/packages/Scope_Manager.mdx
index 0afbdd4690c7..93ea52122877 100644
--- a/docs/packages/Scope_Manager.mdx
+++ b/docs/packages/Scope_Manager.mdx
@@ -67,6 +67,17 @@ interface AnalyzeOptions {
    */
   sourceType?: 'script' | 'module';
 
+  /**
+   * Whether to resolve references to global `var`/function declarations when `sourceType` is `script`.
+   *
+   * - Defaults to `false` (matches ESLint 8/9 behavior): global `var`/function references stay in `through`.
+   * - Set to `true` to opt into ESLint 10 behavior: script-mode global `var`/function references are resolved before rules run.
+   *
+   * This is mainly relevant for ESLint 10 users; ESLint 8/9 users don’t need to change anything.
+   */
+  resolveGlobalVarsInScript?: boolean;
+  // Injected globals are value-only by default; type references will not bind unless the variable is marked type-capable.
+
   /**
    * Emit design-type metadata for decorated declarations in source.
    * Defaults to `false`.
@@ -89,6 +100,16 @@ const ast = parse(code, {
 const scope = analyze(ast, {
   sourceType: 'module',
 });
+
+// ESLint 10 script-mode global resolution (opt-in):
+// const scopeScript = analyze(astScript, {
+//   sourceType: 'script',
+//   resolveGlobalVarsInScript: true, // resolve global var/function refs before rules run
+// });
+// Note: ESLint 8/9 users should leave `resolveGlobalVarsInScript` unset (default false).
+// ESLint 10 users should set it to true to match ESLint 10's script-mode contract.
+
+// Changelog note: addGlobals + resolveGlobalVarsInScript support ESLint 10. ESLint 8/9 users need no change; ESLint 10 users should opt in for script mode.
 ```
 
 ## References
diff --git a/packages/scope-manager/src/ScopeManager.ts b/packages/scope-manager/src/ScopeManager.ts
index 63241e98271a..5e00eae8b155 100644
--- a/packages/scope-manager/src/ScopeManager.ts
+++ b/packages/scope-manager/src/ScopeManager.ts
@@ -1,5 +1,6 @@
 import type { SourceType, TSESTree } from '@typescript-eslint/types';
 
+import type { Reference } from './referencer/Reference';
 import type { Scope } from './scope';
 import type { Variable } from './variable';
 
@@ -30,6 +31,11 @@ interface ScopeManagerOptions {
   globalReturn?: boolean;
   impliedStrict?: boolean;
   sourceType?: SourceType;
+  /**
+   * When true, references to global var/function declarations are resolved in script mode.
+   * Defaults to false (ESLint 8/9 behavior): global `var` references remain in `through`.
+   */
+  resolveGlobalVarsInScript?: boolean;
 }
 
 /**
@@ -84,6 +90,11 @@ export class ScopeManager {
     return true;
   }
 
+  public shouldResolveGlobalVarsInScript(): boolean {
+    // Default false (ESLint 9 behavior). Opt in to ESLint 10 script-mode resolution by setting true.
+    return this.#options.resolveGlobalVarsInScript === true;
+  }
+
   public get variables(): Variable[] {
     const variables = new Set<Variable>();
     function recurse(scope: Scope): void {
@@ -259,6 +270,76 @@ export class ScopeManager {
     return this.nestScope(new WithScope(this, this.currentScope, node));
   }
 
+  /**
+   * Adds declared globals to the global scope.
+   *
+   * Used by ESLint to inject configured globals; required by ESLint 10+.
+   *
+   * We default to value-only globals (`isTypeVariable: false`, `isValueVariable: true`)
+   * so we don’t accidentally satisfy type-only references and hide missing ambient types.
+   * Unresolved references are rebound when names match.
+   * If a future use case needs type-capable injected globals, set `isTypeVariable: true`
+   * so type references can bind; the guard below will honor it.
+   */
+  public addGlobals(names: string[]): void {
+    const globalScope = this.globalScope;
+    if (!globalScope || !Array.isArray(names)) {
+      return;
+    }
+
+    const unique = new Set<string>();
+    for (const name of names) {
+      if (typeof name === 'string' && name.length > 0) {
+        unique.add(name);
+      }
+    }
+    if (unique.size === 0) {
+      return;
+    }
+
+    for (const name of unique) {
+      if (!globalScope.set.has(name)) {
+        // mimic implicit global definition (no defs/identifiers) but ensure bookkeeping is consistent
+        globalScope.defineImplicitVariable(name, {
+          isTypeVariable: false,
+          isValueVariable: true,
+        });
+      }
+    }
+
+    const remainingThrough: typeof globalScope.through = [];
+    for (const ref of globalScope.through) {
+      const refName = ref.identifier.name;
+      const variable = unique.has(refName)
+        ? globalScope.set.get(refName)
+        : null;
+      // Injected globals are value-only by default; bind value refs, and only bind type refs when the variable is marked type-capable.
+      const canBind =
+        variable &&
+        ((ref.isValueReference && variable.isValueVariable) ||
+          (ref.isTypeReference && variable.isTypeVariable));
+      if (canBind) {
+        variable.references.push(ref);
+        ref.resolved = variable;
+        continue;
+      }
+      remainingThrough.push(ref);
+    }
+    globalScope.through.length = 0;
+    globalScope.through.push(...remainingThrough);
+
+    // Optional parity with eslint-scope: drop matching entries from implicit left-to-be-resolved.
+    // Access GlobalScope's private `implicit` field for eslint-scope compatibility; safe because
+    // implicit.leftToBeResolved is part of the eslint-scope contract. If eslint-scope changes this
+    // shape, we should revisit.
+    const implicit = getImplicit(globalScope);
+    if (implicit) {
+      implicit.leftToBeResolved = implicit.leftToBeResolved.filter(
+        ref => !unique.has(ref.identifier.name),
+      );
+    }
+  }
+
   // Scope helpers
 
   protected nestScope<T extends Scope>(scope: T): T;
@@ -271,3 +352,20 @@ export class ScopeManager {
     return scope;
   }
 }
+
+interface ImplicitState {
+  leftToBeResolved: Reference[];
+}
+
+function getImplicit(scope: GlobalScope | null): ImplicitState | undefined {
+  const candidate = scope as unknown as { implicit?: ImplicitState } | null;
+  // eslint-scope compat: implicit is a private field; we intentionally reach it to
+  // mirror eslint-scope's cleanup of implicit.leftToBeResolved on global injection.
+  if (!candidate?.implicit) {
+    return undefined;
+  }
+  if (!Array.isArray(candidate.implicit.leftToBeResolved)) {
+    return undefined;
+  }
+  return candidate.implicit;
+}
diff --git a/packages/scope-manager/src/analyze.ts b/packages/scope-manager/src/analyze.ts
index a050a723c42e..d7087892681c 100644
--- a/packages/scope-manager/src/analyze.ts
+++ b/packages/scope-manager/src/analyze.ts
@@ -59,6 +59,13 @@ export interface AnalyzeOptions {
    */
   sourceType?: SourceType;
 
+  /**
+   * Whether to resolve references to global `var`/function declarations when `sourceType` is `script`.
+   * Defaults to `false` (ESLint 9 behavior) to preserve support for the current eslint range (^8.57.0 || ^9.0.0).
+   * Set to `true` to opt into ESLint 10 behavior where such references are resolved out of `through`.
+   */
+  resolveGlobalVarsInScript?: boolean;
+
   // TODO - remove this in v10
   /**
    * @deprecated This option never did what it was intended for and will be removed in a future major release.
@@ -74,6 +81,8 @@ const DEFAULT_OPTIONS: Required<AnalyzeOptions> = {
   jsxFragmentName: null,
   jsxPragma: 'React',
   lib: ['es2018'],
+  // TODO(major): flip to true when ESLint 10 is within the supported range (see supported ESLint versions in project docs).
+  resolveGlobalVarsInScript: false,
   sourceType: 'script',
 };
 
@@ -99,6 +108,9 @@ export function analyze(
         ? DEFAULT_OPTIONS.jsxPragma
         : providedOptions.jsxPragma,
     lib: providedOptions?.lib ?? ['esnext'],
+    resolveGlobalVarsInScript:
+      providedOptions?.resolveGlobalVarsInScript ??
+      DEFAULT_OPTIONS.resolveGlobalVarsInScript,
     sourceType: providedOptions?.sourceType ?? DEFAULT_OPTIONS.sourceType,
   };
 
diff --git a/packages/scope-manager/src/scope/ScopeBase.ts b/packages/scope-manager/src/scope/ScopeBase.ts
index 18e405e29e02..3a5830f03334 100644
--- a/packages/scope-manager/src/scope/ScopeBase.ts
+++ b/packages/scope-manager/src/scope/ScopeBase.ts
@@ -330,20 +330,27 @@ export abstract class ScopeBase<
       return true;
     }
 
-    // in script mode, only certain cases should be statically resolved
-    // Example:
-    // a `var` decl is ignored by the runtime if it clashes with a global name
-    // this means that we should not resolve the reference to the variable
-    const defs = variable.defs;
-    return (
-      defs.length > 0 &&
-      defs.every(def => {
-        if (def.type === DefinitionType.Variable && def.parent.kind === 'var') {
-          return false;
-        }
-        return true;
-      })
-    );
+    if (!scopeManager.shouldResolveGlobalVarsInScript()) {
+      // Legacy/ESLint 9 behavior: in script mode, only certain cases should be statically resolved.
+      // Example: a `var` decl is ignored by the runtime if it clashes with a global name, so
+      // we should not resolve the reference to the variable.
+      // In effect: resolve only if no definition is a `var` declaration.
+      const defs = variable.defs;
+      return (
+        defs.length > 0 &&
+        defs.every(
+          def =>
+            def.type !== DefinitionType.Variable ||
+            !(
+              def.parent.type === AST_NODE_TYPES.VariableDeclaration &&
+              def.parent.kind === 'var'
+            ),
+        )
+      );
+    }
+
+    // ESLint 10 behavior: resolve references to globals declared with var/function even in script mode.
+    return variable.defs.length > 0;
   }
 
   public close(scopeManager: ScopeManager): Scope | null {
diff --git a/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts b/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
new file mode 100644
index 000000000000..2c1483ea5914
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
@@ -0,0 +1,187 @@
+import { parseAndAnalyze } from '../test-utils';
+
+describe('addGlobals (extra cases)', () => {
+  it('deduplicates and binds multiple globals', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      console.log(a, b);
+    `,
+      { sourceType: 'script' },
+    );
+
+    scopeManager.addGlobals(['a', 'a', 'b']);
+
+    const globalScope = scopeManager.globalScope!;
+
+    const varA = globalScope.set.get('a');
+    const varB = globalScope.set.get('b');
+    expect(varA).toBeDefined();
+    expect(varB).toBeDefined();
+
+    expect(varA!.references.some(ref => ref.identifier.name === 'a')).toBe(
+      true,
+    );
+    expect(varB!.references.some(ref => ref.identifier.name === 'b')).toBe(
+      true,
+    );
+
+    // console remains unresolved
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('ignores non-string/empty names', () => {
+    const { scopeManager } = parseAndAnalyze('console.log(x);', {
+      sourceType: 'script',
+    });
+
+    // @ts-expect-error testing defensive handling
+    scopeManager.addGlobals(['', null, 'x']);
+
+    const globalScope = scopeManager.globalScope!;
+    const varX = globalScope.set.get('x');
+    expect(varX).toBeDefined();
+    expect(varX!.references.length).toBeGreaterThan(0);
+
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('does not double-bind when a global already exists', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      console.log(a);
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const beforeThrough = [...scopeManager.globalScope!.through];
+
+    scopeManager.addGlobals(['a']);
+
+    const globalScope = scopeManager.globalScope!;
+    const varA = globalScope.set.get('a');
+    expect(varA).toBeDefined();
+
+    // through should not gain duplicates; console remains, a is resolved
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+    // sanity: through size does not grow after addGlobals
+    expect(globalScope.through.length).toBeLessThanOrEqual(
+      beforeThrough.length,
+    );
+  });
+
+  it('removes implicit unresolved when injected', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      foo = 1;
+    `,
+      { sourceType: 'script' },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.through.some(ref => ref.identifier.name === 'foo')).toBe(
+      true,
+    );
+
+    scopeManager.addGlobals(['foo']);
+
+    expect(globalScope.through.some(ref => ref.identifier.name === 'foo')).toBe(
+      false,
+    );
+  });
+
+  it('handles an empty names array as a no-op', () => {
+    const { scopeManager } = parseAndAnalyze('foo;');
+    const throughBefore = scopeManager.globalScope!.through.length;
+    scopeManager.addGlobals([]);
+    expect(scopeManager.globalScope!.through.length).toBe(throughBefore);
+  });
+
+  it('handles multiple addGlobals calls with different names', () => {
+    const { scopeManager } = parseAndAnalyze('foo; bar; baz;');
+
+    scopeManager.addGlobals(['foo']);
+    scopeManager.addGlobals(['bar']);
+
+    const throughNames = scopeManager.globalScope!.through.map(
+      ref => ref.identifier.name,
+    );
+    expect(throughNames).toEqual(['baz']);
+  });
+
+  it('is a no-op when names is not an array', () => {
+    const { scopeManager } = parseAndAnalyze('foo;');
+    const throughBefore = scopeManager.globalScope!.through.length;
+    // @ts-expect-error testing defensive branch
+    scopeManager.addGlobals(null);
+    expect(scopeManager.globalScope!.through.length).toBe(throughBefore);
+  });
+
+  it('typeof query in type position does not bind to value-only globals', () => {
+    const { scopeManager } = parseAndAnalyze('type X = typeof foo;');
+    const globalScope = scopeManager.globalScope!;
+
+    scopeManager.addGlobals(['foo']);
+
+    const fooVar = globalScope.set.get('foo');
+    expect(fooVar).toBeDefined();
+    // Injected variable should not pick up type-only references even if ESLint treats them as globals.
+    expect(fooVar!.references.some(ref => ref.isTypeReference)).toBe(false);
+  });
+
+  it('binds value-side heritage references for injected globals', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      class MyErr extends Error {}
+      new MyErr();
+    `,
+      { sourceType: 'script' },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    // Before injection, Error should be unresolved.
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'Error'),
+    ).toBe(true);
+
+    scopeManager.addGlobals(['Error']);
+
+    const errorVar = globalScope.set.get('Error');
+    expect(errorVar).toBeDefined();
+    // Ensure at least the value-side reference (heritage) is bound.
+    expect(
+      errorVar!.references.some(
+        ref => ref.identifier.name === 'Error' && ref.isValueReference,
+      ),
+    ).toBe(true);
+    // No type references should be attached to the injected global by default.
+    expect(errorVar!.references.some(ref => ref.isTypeReference)).toBe(false);
+  });
+
+  it('type-only refs remain unresolved for injected globals', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      type Only = GlobalType;
+    `,
+      { sourceType: 'script' },
+    );
+
+    scopeManager.addGlobals(['GlobalType']);
+    const globalScope = scopeManager.globalScope!;
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'GlobalType'),
+    ).toBe(true);
+    const varGlobal = globalScope.set.get('GlobalType');
+    expect(varGlobal).toBeDefined();
+    expect(varGlobal!.references.some(ref => ref.isTypeReference)).toBe(false);
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/add-globals.test.ts b/packages/scope-manager/tests/eslint-scope/add-globals.test.ts
new file mode 100644
index 000000000000..3c44475b8eae
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/add-globals.test.ts
@@ -0,0 +1,136 @@
+import { analyze } from '../../src/analyze';
+import { ScopeType } from '../../src/scope';
+import { parse, parseAndAnalyze } from '../test-utils';
+
+describe('addGlobals', () => {
+  it('binds unresolved globals to injected variables', () => {
+    const ast = parse('foo = 1;');
+    const scopeManager = analyze(ast);
+
+    const globalScope = scopeManager.globalScope;
+    expect(globalScope).not.toBeNull();
+    const scope = globalScope!;
+    expect(scope.type).toBe(ScopeType.global);
+    expect(scope.through).toHaveLength(1);
+    expect(scope.through[0].identifier.name).toBe('foo');
+
+    scopeManager.addGlobals(['foo']);
+
+    expect(scope.set.has('foo')).toBe(true);
+    const variable = scope.set.get('foo');
+    expect(variable).toBeDefined();
+    expect(variable!.references).toHaveLength(1);
+    expect(variable!.references[0].identifier.name).toBe('foo');
+    expect(scope.through).toHaveLength(0);
+  });
+
+  it('is idempotent when called multiple times', () => {
+    const ast = parse('foo;');
+    const scopeManager = analyze(ast);
+    const scope = scopeManager.globalScope!;
+
+    scopeManager.addGlobals(['foo']);
+    scopeManager.addGlobals(['foo']);
+
+    const variable = scope.set.get('foo');
+    expect(variable).toBeDefined();
+    expect(variable!.references).toHaveLength(1);
+    expect(scope.through).toHaveLength(0);
+  });
+
+  it('does not bind type references when globals are value-only', () => {
+    const { scopeManager } = parseAndAnalyze('type T = Foo;');
+    const scope = scopeManager.globalScope!;
+
+    expect(scope.through).toHaveLength(1);
+    const ref = scope.through[0];
+    expect(ref.isTypeReference).toBe(true);
+    expect(ref.resolved).toBeNull();
+
+    scopeManager.addGlobals(['Foo']);
+
+    const variable = scope.set.get('Foo');
+    expect(variable).toBeDefined();
+    expect(variable!.isTypeVariable).toBe(false);
+    expect(variable!.references).toHaveLength(0);
+    expect(scope.through).toHaveLength(1);
+    expect(scope.through[0]).toBe(ref);
+    expect(scope.through[0].resolved).toBeNull();
+  });
+
+  it('binds value refs but not type refs for the same injected name', () => {
+    const { scopeManager } = parseAndAnalyze('type T = Foo; const x = Foo;');
+    const scope = scopeManager.globalScope!;
+
+    // Expect one type ref (Foo in type T) and one value ref (Foo in const x).
+    const typeRefs = scope.through.filter(ref => ref.isTypeReference);
+    const valueRefs = scope.through.filter(ref => !ref.isTypeReference);
+    expect(typeRefs).toHaveLength(1);
+    expect(valueRefs).toHaveLength(1);
+
+    scopeManager.addGlobals(['Foo']);
+
+    const variable = scope.set.get('Foo');
+    expect(variable).toBeDefined();
+    expect(variable!.isTypeVariable).toBe(false);
+
+    // Value ref should bind.
+    expect(variable!.references.some(ref => !ref.isTypeReference)).toBe(true);
+    // Type ref should remain unresolved.
+    expect(typeRefs[0].resolved).toBeNull();
+    expect(scope.through).toContain(typeRefs[0]);
+    // Only the type ref remains in through.
+    expect(scope.through).toHaveLength(1);
+  });
+
+  it('does not bind dual (type+value) references for value-only globals', () => {
+    const { scopeManager } = parseAndAnalyze('const x: typeof Foo = Foo;');
+    const scope = scopeManager.globalScope!;
+
+    const dualRefs = scope.through.filter(
+      ref => ref.isTypeReference && !ref.isValueReference,
+    );
+    // In practice, the typeof Foo in the type position is a type ref; Foo in value position is a value ref.
+    expect(scope.through.length).toBeGreaterThanOrEqual(2);
+
+    scopeManager.addGlobals(['Foo']);
+
+    const variable = scope.set.get('Foo');
+    expect(variable).toBeDefined();
+    expect(variable!.isTypeVariable).toBe(false);
+
+    // Value side should bind.
+    expect(variable!.references.some(ref => !ref.isTypeReference)).toBe(true);
+    // Type side should remain unresolved.
+    for (const ref of dualRefs) {
+      expect(ref.resolved).toBeNull();
+    }
+  });
+
+  it('binds multiple injected globals in one call', () => {
+    const { scopeManager } = parseAndAnalyze('foo; bar; baz;');
+    const scope = scopeManager.globalScope!;
+
+    expect(scope.through).toHaveLength(3);
+    scopeManager.addGlobals(['foo', 'bar', 'baz']);
+
+    expect(scope.through).toHaveLength(0);
+    expect(scope.set.has('foo')).toBe(true);
+    expect(scope.set.has('bar')).toBe(true);
+    expect(scope.set.has('baz')).toBe(true);
+  });
+
+  it('resolves references to global var declarations in script mode', () => {
+    const { scopeManager } = parseAndAnalyze('var foo; console.log(foo);', {
+      sourceType: 'script',
+      resolveGlobalVarsInScript: true,
+    });
+    const scope = scopeManager.globalScope!;
+
+    const foo = scope.set.get('foo');
+    expect(foo).toBeDefined();
+    expect(foo!.references.length).toBeGreaterThan(0);
+    expect(scope.through).toHaveLength(1);
+    expect(scope.through[0].identifier.name).toBe('console');
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/label-script-default.test.ts b/packages/scope-manager/tests/eslint-scope/label-script-default.test.ts
new file mode 100644
index 000000000000..eab8d54e4a22
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/label-script-default.test.ts
@@ -0,0 +1,37 @@
+import { ScopeType } from '../../src/scope';
+import { getRealVariables, parseAndAnalyze } from '../test-utils';
+
+describe('label (script default: globals stay through)', () => {
+  it('should count child node references when globals are not resolved', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var foo = 5;
+
+      label: while (true) {
+        console.log(foo);
+        break;
+      }
+    `,
+      { resolveGlobalVarsInScript: false },
+    );
+
+    expect(scopeManager.scopes).toHaveLength(2);
+
+    let scope = scopeManager.scopes[0];
+    let variables = getRealVariables(scope.variables);
+    assert.isScopeOfType(scope, ScopeType.global);
+    expect(variables).toHaveLength(1);
+    expect(variables[0].name).toBe('foo');
+    expect(scope.through).toHaveLength(3);
+    expect(scope.through[2].identifier.name).toBe('foo');
+    expect(scope.through[2].isRead()).toBe(true);
+
+    scope = scopeManager.scopes[1];
+    variables = getRealVariables(scope.variables);
+    assert.isScopeOfType(scope, ScopeType.block);
+    expect(variables).toHaveLength(0);
+    expect(scope.references).toHaveLength(2);
+    expect(scope.references[0].identifier.name).toBe('console');
+    expect(scope.references[1].identifier.name).toBe('foo');
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts b/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts
new file mode 100644
index 000000000000..b83486a81ba2
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts
@@ -0,0 +1,24 @@
+import { ScopeType } from '../../src/scope';
+import { parseAndAnalyze } from '../test-utils';
+
+describe('module var scoping (flag has no effect)', () => {
+  it('keeps var scoped to module (not global)', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      a;
+    `,
+      { sourceType: 'module', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.type).toBe(ScopeType.global);
+    // var a should not live in the global scope set for modules
+    expect(globalScope.set.has('a')).toBe(false);
+    // module scope should own 'a'
+    const moduleScope = scopeManager.scopes.find(
+      s => s.type === ScopeType.module,
+    );
+    expect(moduleScope?.set.has('a')).toBe(true);
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/references-script-default.test.ts b/packages/scope-manager/tests/eslint-scope/references-script-default.test.ts
new file mode 100644
index 000000000000..34976588ebdb
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/references-script-default.test.ts
@@ -0,0 +1,60 @@
+import { parseAndAnalyze } from '../test-utils';
+import { getRealVariables } from '../test-utils/misc';
+
+describe('references (script default: globals stay through)', () => {
+  describe('When there is a `var` declaration on global (default)', () => {
+    it('the reference on global should NOT be resolved.', () => {
+      const { scopeManager } = parseAndAnalyze('var a = 0;', {
+        resolveGlobalVarsInScript: false,
+      });
+
+      expect(scopeManager.scopes).toHaveLength(1);
+
+      const scope = scopeManager.scopes[0];
+      const variables = getRealVariables(scope.variables);
+
+      expect(variables).toHaveLength(1);
+      expect(scope.references).toHaveLength(1);
+
+      const reference = scope.references[0];
+
+      expect(reference.from).toBe(scope);
+      expect(reference.identifier.name).toBe('a');
+
+      expect(reference.resolved).toBeNull();
+
+      expect(reference.isWrite()).toBe(true);
+      expect(reference.isRead()).toBe(false);
+    });
+
+    it('the reference in functions should NOT be resolved.', () => {
+      const { scopeManager } = parseAndAnalyze(
+        `
+        var a = 0;
+        function foo() {
+          var b = a;
+        }
+      `,
+        { resolveGlobalVarsInScript: false },
+      );
+
+      expect(scopeManager.scopes).toHaveLength(2); // [global, foo]
+
+      const scope = scopeManager.scopes[1];
+      const variables = getRealVariables(scope.variables);
+
+      expect(variables).toHaveLength(2); // [arguments, b]
+      expect(scope.references).toHaveLength(2); // [b, a]
+
+      const reference = scope.references[1];
+
+      expect(reference.from).toBe(scope);
+      expect(reference.identifier.name).toBe('a');
+
+      expect(reference.resolved).toBeNull();
+
+      expect(reference.isWrite()).toBe(false);
+      expect(reference.isRead()).toBe(true);
+    });
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts b/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts
new file mode 100644
index 000000000000..719af98df45f
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts
@@ -0,0 +1,143 @@
+import { ScopeType } from '../../src/scope';
+import { parseAndAnalyze } from '../test-utils';
+
+describe('script globals: default vs opt-in', () => {
+  it('default (ESLint 8/9): globals stay through', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      console.log(a);
+      var a = 1;
+    `,
+      { sourceType: 'script' },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    const aVar = globalScope.set.get('a');
+    expect(aVar).toBeDefined();
+
+    // a is not resolved; remains in through
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      true,
+    );
+    // console is also through
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('opt-in (ESLint 10): globals resolved in script mode', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      console.log(a);
+      var a = 1;
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.type).toBe(ScopeType.global);
+    const aVar = globalScope.set.get('a');
+    expect(aVar).toBeDefined();
+
+    // a is resolved; no longer in through
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+    // console still through
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('dual type/value ref does not bind type side when globals injected', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      const x: typeof Foo = Foo;
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    scopeManager.addGlobals(['Foo']);
+
+    const globalScope = scopeManager.globalScope!;
+    const fooVar = globalScope.set.get('Foo');
+    expect(fooVar).toBeDefined();
+
+    // value ref can bind; type ref should remain unresolved (still in through)
+    const valueRef = fooVar!.references.find(ref => ref.isValueReference);
+    expect(valueRef).toBeDefined();
+    // ensure injected variable did not pick up any type references
+    expect(fooVar!.references.some(ref => ref.isTypeReference)).toBe(false);
+  });
+
+  it('function declarations resolve in script mode when opted-in', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      function foo() {}
+      foo();
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    const fooVar = globalScope.set.get('foo');
+    expect(fooVar).toBeDefined();
+    expect(fooVar!.references.length).toBeGreaterThan(0);
+    expect(globalScope.through.some(ref => ref.identifier.name === 'foo')).toBe(
+      false,
+    );
+  });
+
+  it('let/const resolve in script mode even when flag is false', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      let a = 1;
+      const b = 2;
+      console.log(a, b);
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: false },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+    expect(globalScope.through.some(ref => ref.identifier.name === 'b')).toBe(
+      false,
+    );
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('module mode is unaffected by the script flag', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      a;
+    `,
+      { sourceType: 'module', resolveGlobalVarsInScript: false },
+    );
+
+    // module scopes do not place var in the global scope set
+    expect(scopeManager.globalScope!.set.has('a')).toBe(false);
+  });
+
+  it('class declarations resolve in script mode even when flag is false', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      class Foo {}
+      new Foo();
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: false },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.through.some(ref => ref.identifier.name === 'Foo')).toBe(
+      false,
+    );
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(false);
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts b/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts
new file mode 100644
index 000000000000..b1b2f6c8495d
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts
@@ -0,0 +1,77 @@
+import { parseAndAnalyze } from '../test-utils';
+
+describe('script globals: edge cases', () => {
+  it('TDZ with let/const still resolves identifiers (no through entry)', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      console.log(a);
+      let a = 1;
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: false },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('with block prevents static resolution even when opted-in', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      with (obj) {
+        console.log(a);
+      }
+      var a = 1;
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    // Current scope resolution still binds `a` even with a `with` block present.
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+    expect(
+      globalScope.through.some(ref => ref.identifier.name === 'console'),
+    ).toBe(true);
+  });
+
+  it('multiple var declarations resolve to the same global when opted-in', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      var a = 2;
+      a;
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+    const aVar = globalScope.set.get('a');
+    expect(aVar).toBeDefined();
+    expect(aVar!.references.length).toBeGreaterThanOrEqual(1);
+  });
+
+  it('eval usage does not prevent static resolution when opted-in', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      eval('');
+      a;
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.through.some(ref => ref.identifier.name === 'a')).toBe(
+      false,
+    );
+  });
+});
diff --git a/packages/scope-manager/tests/eslint-scope/script-nested.test.ts b/packages/scope-manager/tests/eslint-scope/script-nested.test.ts
new file mode 100644
index 000000000000..9dab33bf36cd
--- /dev/null
+++ b/packages/scope-manager/tests/eslint-scope/script-nested.test.ts
@@ -0,0 +1,57 @@
+import { ScopeType } from '../../src/scope';
+import { parseAndAnalyze } from '../test-utils';
+
+describe('Global resolution in script mode', () => {
+  it('resolves global var references in nested functions', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      function foo() {
+        function bar() {
+          return a;
+        }
+      }
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    const globalScope = scopeManager.globalScope!;
+    expect(globalScope.type).toBe(ScopeType.global);
+
+    const aVar = globalScope.set.get('a');
+    expect(aVar).toBeDefined();
+
+    const fooScope = globalScope.childScopes[0];
+    const barScope = fooScope.childScopes[0];
+
+    expect(barScope.references).toHaveLength(1);
+    const ref = barScope.references[0];
+    expect(ref.identifier.name).toBe('a');
+    expect(ref.resolved).toBe(aVar);
+  });
+
+  it('resolves multiple mixed globals injected via addGlobals', () => {
+    const { scopeManager } = parseAndAnalyze(
+      `
+      var a = 1;
+      console.log(b);
+    `,
+      { sourceType: 'script', resolveGlobalVarsInScript: true },
+    );
+
+    scopeManager.addGlobals(['b']);
+
+    const globalScope = scopeManager.globalScope!;
+    const bVar = globalScope.set.get('b');
+    expect(bVar).toBeDefined();
+
+    expect(bVar!.references.length).toBeGreaterThan(0);
+    const foundRef = bVar!.references[0];
+    expect(foundRef.identifier.name).toBe('b');
+
+    const consoleRef = globalScope.through.find(
+      r => r.identifier.name === 'console',
+    );
+    expect(consoleRef).toBeDefined();
+  });
+});

From 1c5520ee5e2e60de4d23cc0d211f778ecbe19e4e Mon Sep 17 00:00:00 2001
From: Michael Giraldo <michael.giraldo@gmail.com>
Date: Mon, 8 Dec 2025 18:21:41 -0800
Subject: [PATCH 2/4] chore(scope-manager): rephrase eslint8/9 comment

---
 packages/scope-manager/src/scope/ScopeBase.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/packages/scope-manager/src/scope/ScopeBase.ts b/packages/scope-manager/src/scope/ScopeBase.ts
index 3a5830f03334..47beb84682a1 100644
--- a/packages/scope-manager/src/scope/ScopeBase.ts
+++ b/packages/scope-manager/src/scope/ScopeBase.ts
@@ -331,9 +331,8 @@ export abstract class ScopeBase<
     }
 
     if (!scopeManager.shouldResolveGlobalVarsInScript()) {
-      // Legacy/ESLint 9 behavior: in script mode, only certain cases should be statically resolved.
-      // Example: a `var` decl is ignored by the runtime if it clashes with a global name, so
-      // we should not resolve the reference to the variable.
+      // ESLint 8/9 behavior: in script mode, only certain cases should be statically resolved.
+      // Example: a `var` decl is ignored by the runtime if it clashes with a global name, so do not resolve it here.
       // In effect: resolve only if no definition is a `var` declaration.
       const defs = variable.defs;
       return (

From 1411ac0079bebb52c3184e98318aae3c906089d7 Mon Sep 17 00:00:00 2001
From: Michael Giraldo <michael.giraldo@gmail.com>
Date: Mon, 8 Dec 2025 19:00:15 -0800
Subject: [PATCH 3/4] chore(scope-manager): fix lint ordering and assertions

---
 packages/scope-manager/src/scope/ScopeBase.ts |  6 +--
 .../eslint-scope/add-globals-extra.test.ts    | 41 ++++++++++++-------
 .../tests/eslint-scope/add-globals.test.ts    |  2 +-
 .../eslint-scope/module-var-scope.test.ts     |  2 +-
 .../script-globals-default-vs-opt-in.test.ts  | 14 +++----
 .../script-globals-edge-cases.test.ts         |  8 ++--
 .../tests/eslint-scope/script-nested.test.ts  |  4 +-
 7 files changed, 42 insertions(+), 35 deletions(-)

diff --git a/packages/scope-manager/src/scope/ScopeBase.ts b/packages/scope-manager/src/scope/ScopeBase.ts
index 47beb84682a1..be4104fbf5e1 100644
--- a/packages/scope-manager/src/scope/ScopeBase.ts
+++ b/packages/scope-manager/src/scope/ScopeBase.ts
@@ -339,11 +339,7 @@ export abstract class ScopeBase<
         defs.length > 0 &&
         defs.every(
           def =>
-            def.type !== DefinitionType.Variable ||
-            !(
-              def.parent.type === AST_NODE_TYPES.VariableDeclaration &&
-              def.parent.kind === 'var'
-            ),
+            def.type !== DefinitionType.Variable || def.parent.kind !== 'var',
         )
       );
     }
diff --git a/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts b/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
index 2c1483ea5914..a8fddfd7c92b 100644
--- a/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
@@ -6,7 +6,7 @@ describe('addGlobals (extra cases)', () => {
       `
       console.log(a, b);
     `,
-      { sourceType: 'script' },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     scopeManager.addGlobals(['a', 'a', 'b']);
@@ -33,6 +33,7 @@ describe('addGlobals (extra cases)', () => {
 
   it('ignores non-string/empty names', () => {
     const { scopeManager } = parseAndAnalyze('console.log(x);', {
+      resolveGlobalVarsInScript: false,
       sourceType: 'script',
     });
 
@@ -42,7 +43,7 @@ describe('addGlobals (extra cases)', () => {
     const globalScope = scopeManager.globalScope!;
     const varX = globalScope.set.get('x');
     expect(varX).toBeDefined();
-    expect(varX!.references.length).toBeGreaterThan(0);
+    expect(varX!.references).toHaveLength(1);
 
     expect(
       globalScope.through.some(ref => ref.identifier.name === 'console'),
@@ -55,7 +56,7 @@ describe('addGlobals (extra cases)', () => {
       var a = 1;
       console.log(a);
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const beforeThrough = [...scopeManager.globalScope!.through];
@@ -74,9 +75,7 @@ describe('addGlobals (extra cases)', () => {
       false,
     );
     // sanity: through size does not grow after addGlobals
-    expect(globalScope.through.length).toBeLessThanOrEqual(
-      beforeThrough.length,
-    );
+    expect(globalScope.through).toHaveLength(beforeThrough.length);
   });
 
   it('removes implicit unresolved when injected', () => {
@@ -84,7 +83,7 @@ describe('addGlobals (extra cases)', () => {
       `
       foo = 1;
     `,
-      { sourceType: 'script' },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -100,14 +99,20 @@ describe('addGlobals (extra cases)', () => {
   });
 
   it('handles an empty names array as a no-op', () => {
-    const { scopeManager } = parseAndAnalyze('foo;');
+    const { scopeManager } = parseAndAnalyze('foo;', {
+      resolveGlobalVarsInScript: false,
+      sourceType: 'script',
+    });
     const throughBefore = scopeManager.globalScope!.through.length;
     scopeManager.addGlobals([]);
-    expect(scopeManager.globalScope!.through.length).toBe(throughBefore);
+    expect(scopeManager.globalScope!.through).toHaveLength(throughBefore);
   });
 
   it('handles multiple addGlobals calls with different names', () => {
-    const { scopeManager } = parseAndAnalyze('foo; bar; baz;');
+    const { scopeManager } = parseAndAnalyze('foo; bar; baz;', {
+      resolveGlobalVarsInScript: false,
+      sourceType: 'script',
+    });
 
     scopeManager.addGlobals(['foo']);
     scopeManager.addGlobals(['bar']);
@@ -119,15 +124,21 @@ describe('addGlobals (extra cases)', () => {
   });
 
   it('is a no-op when names is not an array', () => {
-    const { scopeManager } = parseAndAnalyze('foo;');
+    const { scopeManager } = parseAndAnalyze('foo;', {
+      resolveGlobalVarsInScript: false,
+      sourceType: 'script',
+    });
     const throughBefore = scopeManager.globalScope!.through.length;
     // @ts-expect-error testing defensive branch
     scopeManager.addGlobals(null);
-    expect(scopeManager.globalScope!.through.length).toBe(throughBefore);
+    expect(scopeManager.globalScope!.through).toHaveLength(throughBefore);
   });
 
   it('typeof query in type position does not bind to value-only globals', () => {
-    const { scopeManager } = parseAndAnalyze('type X = typeof foo;');
+    const { scopeManager } = parseAndAnalyze('type X = typeof foo;', {
+      resolveGlobalVarsInScript: false,
+      sourceType: 'script',
+    });
     const globalScope = scopeManager.globalScope!;
 
     scopeManager.addGlobals(['foo']);
@@ -144,7 +155,7 @@ describe('addGlobals (extra cases)', () => {
       class MyErr extends Error {}
       new MyErr();
     `,
-      { sourceType: 'script' },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -172,7 +183,7 @@ describe('addGlobals (extra cases)', () => {
       `
       type Only = GlobalType;
     `,
-      { sourceType: 'script' },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     scopeManager.addGlobals(['GlobalType']);
diff --git a/packages/scope-manager/tests/eslint-scope/add-globals.test.ts b/packages/scope-manager/tests/eslint-scope/add-globals.test.ts
index 3c44475b8eae..3b97d601508e 100644
--- a/packages/scope-manager/tests/eslint-scope/add-globals.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/add-globals.test.ts
@@ -122,8 +122,8 @@ describe('addGlobals', () => {
 
   it('resolves references to global var declarations in script mode', () => {
     const { scopeManager } = parseAndAnalyze('var foo; console.log(foo);', {
-      sourceType: 'script',
       resolveGlobalVarsInScript: true,
+      sourceType: 'script',
     });
     const scope = scopeManager.globalScope!;
 
diff --git a/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts b/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts
index b83486a81ba2..67d6b58f67d1 100644
--- a/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/module-var-scope.test.ts
@@ -8,7 +8,7 @@ describe('module var scoping (flag has no effect)', () => {
       var a = 1;
       a;
     `,
-      { sourceType: 'module', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'module' },
     );
 
     const globalScope = scopeManager.globalScope!;
diff --git a/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts b/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts
index 719af98df45f..5762a77d3865 100644
--- a/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/script-globals-default-vs-opt-in.test.ts
@@ -8,7 +8,7 @@ describe('script globals: default vs opt-in', () => {
       console.log(a);
       var a = 1;
     `,
-      { sourceType: 'script' },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -31,7 +31,7 @@ describe('script globals: default vs opt-in', () => {
       console.log(a);
       var a = 1;
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -54,7 +54,7 @@ describe('script globals: default vs opt-in', () => {
       `
       const x: typeof Foo = Foo;
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     scopeManager.addGlobals(['Foo']);
@@ -76,7 +76,7 @@ describe('script globals: default vs opt-in', () => {
       function foo() {}
       foo();
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -95,7 +95,7 @@ describe('script globals: default vs opt-in', () => {
       const b = 2;
       console.log(a, b);
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: false },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -116,7 +116,7 @@ describe('script globals: default vs opt-in', () => {
       var a = 1;
       a;
     `,
-      { sourceType: 'module', resolveGlobalVarsInScript: false },
+      { resolveGlobalVarsInScript: false, sourceType: 'module' },
     );
 
     // module scopes do not place var in the global scope set
@@ -129,7 +129,7 @@ describe('script globals: default vs opt-in', () => {
       class Foo {}
       new Foo();
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: false },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
diff --git a/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts b/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts
index b1b2f6c8495d..42aa72d6ae02 100644
--- a/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/script-globals-edge-cases.test.ts
@@ -7,7 +7,7 @@ describe('script globals: edge cases', () => {
       console.log(a);
       let a = 1;
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: false },
+      { resolveGlobalVarsInScript: false, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -27,7 +27,7 @@ describe('script globals: edge cases', () => {
       }
       var a = 1;
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -47,7 +47,7 @@ describe('script globals: edge cases', () => {
       var a = 2;
       a;
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -66,7 +66,7 @@ describe('script globals: edge cases', () => {
       eval('');
       a;
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
diff --git a/packages/scope-manager/tests/eslint-scope/script-nested.test.ts b/packages/scope-manager/tests/eslint-scope/script-nested.test.ts
index 9dab33bf36cd..9107733fe1f2 100644
--- a/packages/scope-manager/tests/eslint-scope/script-nested.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/script-nested.test.ts
@@ -12,7 +12,7 @@ describe('Global resolution in script mode', () => {
         }
       }
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     const globalScope = scopeManager.globalScope!;
@@ -36,7 +36,7 @@ describe('Global resolution in script mode', () => {
       var a = 1;
       console.log(b);
     `,
-      { sourceType: 'script', resolveGlobalVarsInScript: true },
+      { resolveGlobalVarsInScript: true, sourceType: 'script' },
     );
 
     scopeManager.addGlobals(['b']);

From 1c66e96403ef1fa9c61889370312d9d5ff8a8484 Mon Sep 17 00:00:00 2001
From: Michael Giraldo <michael.giraldo@gmail.com>
Date: Mon, 8 Dec 2025 19:18:22 -0800
Subject: [PATCH 4/4] test(scope-manager): cover null/implicit branches

---
 .../eslint-scope/add-globals-extra.test.ts    | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts b/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
index a8fddfd7c92b..6ae88a945bd9 100644
--- a/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
+++ b/packages/scope-manager/tests/eslint-scope/add-globals-extra.test.ts
@@ -1,3 +1,4 @@
+import { ScopeManager } from '../../src/ScopeManager';
 import { parseAndAnalyze } from '../test-utils';
 
 describe('addGlobals (extra cases)', () => {
@@ -195,4 +196,42 @@ describe('addGlobals (extra cases)', () => {
     expect(varGlobal).toBeDefined();
     expect(varGlobal!.references.some(ref => ref.isTypeReference)).toBe(false);
   });
+
+  it('no-ops when globalScope is null', () => {
+    const scopeManager = new ScopeManager({ sourceType: 'script' });
+    scopeManager.addGlobals(['foo']);
+    expect(scopeManager.globalScope).toBeNull();
+  });
+
+  it('tolerates missing implicit state', () => {
+    const { scopeManager } = parseAndAnalyze('foo;', {
+      resolveGlobalVarsInScript: false,
+      sourceType: 'script',
+    });
+
+    const globalScope = scopeManager.globalScope!;
+    delete (globalScope as unknown as { implicit?: unknown }).implicit;
+
+    scopeManager.addGlobals(['foo']);
+    expect(globalScope.through.some(ref => ref.identifier.name === 'foo')).toBe(
+      false,
+    );
+  });
+
+  it('tolerates non-array implicit leftToBeResolved', () => {
+    const { scopeManager } = parseAndAnalyze('foo;', {
+      resolveGlobalVarsInScript: false,
+      sourceType: 'script',
+    });
+
+    const globalScope = scopeManager.globalScope!;
+    (
+      globalScope as unknown as { implicit?: { leftToBeResolved: unknown } }
+    ).implicit = { leftToBeResolved: null };
+
+    scopeManager.addGlobals(['foo']);
+    expect(globalScope.through.some(ref => ref.identifier.name === 'foo')).toBe(
+      false,
+    );
+  });
 });