TL;DR: On the same source and same pnpm install, typescript@6.0.3 and tsgo emit TS7006 / TS7031 on callback parameters that typescript@5.9.3 types correctly. The condition that surfaces it is pnpm's enableGlobalVirtualStore symlink layout — which tsc@5.9.3, Node, and bundlers all handle without issue.
Steps to reproduce
Repro repo (single file, single tsconfig): https://github.com/dougludlow/ts-callback-inference-bug
import type { Meta, StoryObj } from '@storybook/react-vite';
import type { ElementType, ReactNode } from 'react';
interface LabelProps { id: string; children: ReactNode; }
interface WidgetProps { metric: number; slots?: { label?: ElementType<LabelProps> }; }
declare function Widget(props: WidgetProps): ReactNode;
type Story = StoryObj<typeof Widget>;
const meta: Meta<typeof Widget> = { component: Widget };
export default meta;
export const CustomLabel: Story = {
args: {
metric: 50,
slots: {
label: ({ id, children }) => <span id={id}>{children}</span>,
},
},
};Bare tsconfig.json (no strict, no noImplicitAny). pnpm-workspace.yaml contains enableGlobalVirtualStore: true. Commenting that line out makes all three compilers pass on the same source.
Behavior with typescript@5.9.3
Passes.
Behavior with typescript@6.0.3
repro.tsx(29,14): error TS7031: Binding element 'id' implicitly has an 'any' type.
repro.tsx(29,18): error TS7031: Binding element 'children' implicitly has an 'any' type.
Behavior with tsgo (@typescript/native-preview@7.0.0-dev.20260509.2)
Same TS7031 errors as typescript@6.0.3.
Additional context
The repro is the smallest shape I could isolate; in real code the same failure pattern surfaces in Storybook story args, material-react-table cell/header callbacks, Vitest it.each destructuring, MUI event handlers, and Express middleware — anywhere a callback's contextual type comes through a generic from a third-party .d.ts.
preserveSymlinks: true is not a fix. The only workaround we've found is annotating each callsite (({ id, children }: LabelProps)).
Pnpm-side report of the same trigger: pnpm/pnpm#9739.
TL;DR: On the same source and same
pnpminstall,typescript@6.0.3andtsgoemitTS7006/TS7031on callback parameters thattypescript@5.9.3types correctly. The condition that surfaces it is pnpm'senableGlobalVirtualStoresymlink layout — whichtsc@5.9.3, Node, and bundlers all handle without issue.Steps to reproduce
Repro repo (single file, single tsconfig): https://github.com/dougludlow/ts-callback-inference-bug
Bare
tsconfig.json(nostrict, nonoImplicitAny).pnpm-workspace.yamlcontainsenableGlobalVirtualStore: true. Commenting that line out makes all three compilers pass on the same source.Behavior with
typescript@5.9.3Passes.
Behavior with
typescript@6.0.3Behavior with
tsgo(@typescript/native-preview@7.0.0-dev.20260509.2)Same
TS7031errors astypescript@6.0.3.Additional context
The repro is the smallest shape I could isolate; in real code the same failure pattern surfaces in Storybook story args,
material-react-tablecell/header callbacks, Vitestit.eachdestructuring, MUI event handlers, and Express middleware — anywhere a callback's contextual type comes through a generic from a third-party.d.ts.preserveSymlinks: trueis not a fix. The only workaround we've found is annotating each callsite (({ id, children }: LabelProps)).Pnpm-side report of the same trigger: pnpm/pnpm#9739.