feat(types): infer emits from SetupContext in defineComponent

[zhiyuanzmj]

Remove the E extends any ? expression to correctly infer emits from SetupContext.

Don't worry, the #2362 issue has been resolved in this PR after 3.3.0-alpha-7.

Summary by CodeRabbit

• Refactor

  • Simplified the component setup context type to a single, consistent shape, improving type inference behavior.

• Tests

  • Added type-level tests verifying that component emits declared in setup context are correctly reflected as TSX event props.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: ed50f2d4-23b8-4eef-8237-3ece1e6b92da

📥 Commits

Reviewing files that changed from the base of the PR and between 97e569a and a9253f0.

📒 Files selected for processing (1)

• packages-private/dts-test/defineComponent.test-d.tsx

🚧 Files skipped from review as they are similar to previous changes (1)

• packages-private/dts-test/defineComponent.test-d.tsx

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📝 Walkthrough

Walkthrough

Refactored SetupContext from a conditional/distributive type to a single object type and added a type-test that asserts emits declared via SetupContext<['foo']> are reflected as onFoo TSX listener props.

Changes

Cohort / File(s)	Summary
SetupContext Type Refactoring packages/runtime-core/src/component.ts	Replaced the conditional/distributive SetupContext<E = ..., S = ...> = E extends any ? { ... } : never with a direct object type SetupContext<E = ..., S = ...> = { attrs; slots; emit: EmitFn<E>; expose(...) }.
Type Tests for Emits Inference packages-private/dts-test/defineComponent.test-d.tsx	Added a describe('infer emits from SetupContext', ...) test defining Foo and Bar components whose setup uses SetupContext<['foo']> and asserting TSX usage accepts onFoo listener props.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰
I nibbled through types to make them neat,
Flattened a branch where conditionals meet.
Emits now hop out, tidy and spry,
TSX hears onFoo — a joyful cry! 🎉

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: refactoring SetupContext to infer emits from the type parameter, which is the core modification across both the type definition and test additions.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	105 kB	39.9 kB	35.8 kB
vue.global.prod.js	164 kB	59.9 kB	53.2 kB

Usages

Name	Size	Gzip	Brotli
createApp (CAPI only)	48.3 kB	18.8 kB	17.2 kB
createApp	56.5 kB	21.8 kB	20 kB
createSSRApp	60.7 kB	23.6 kB	21.5 kB
defineCustomElement	62.6 kB	23.8 kB	21.7 kB
overall	71 kB	27.2 kB	24.7 kB

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commit: a9253f0

[Copilot]

Pull request overview

This PR adjusts Vue runtime-core TypeScript types to improve inferring component emits from an explicitly-typed SetupContext parameter in setup().

Changes:

• Simplifies SetupContext by removing the distributive conditional (E extends any ? ... : never).
• Adds a dts test ensuring JSX listeners (e.g. onFoo) are inferred when setup() annotates ctx as SetupContext<['foo']>.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/runtime-core/src/component.ts	Changes the exported SetupContext type definition (variance/inference behavior).
packages-private/dts-test/defineComponent.test-d.tsx	Adds a dts regression test for emits inference from SetupContext.

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[zhiyuanzmj]

/ecosystem-ci run

[vue-bot]

📝 Ran ecosystem CI: Open

suite	result	latest scheduled
pinia	✅ success	✅ success
language-tools	❌ failure	❌ failure
quasar	✅ success	✅ success
radix-vue	✅ success	✅ success
nuxt	✅ success	✅ success
primevue	✅ success	✅ success
vue-simple-compiler	✅ success	✅ success
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vueuse	✅ success	✅ success
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