fix: remove runtime helper check

docs/options/target.md

@@ -36,12 +36,14 @@ You can disable all syntax transformations by setting the target to `false`. Thi
 ```
 
 When `target` is set to `false`:
+
 - No JavaScript syntax downleveling occurs (modern features like optional chaining `?.`, nullish coalescing `??`, etc. are preserved)
 - No CSS syntax transformations are applied (modern CSS features like nesting are preserved)
 - No runtime helper plugins are loaded
 - The output will use the exact syntax from your source code
 
 This is particularly useful when:
+
 - You're targeting modern environments that support the latest JavaScript/CSS features
 - You want to handle syntax transformations in a different build step
 - You're building a library that will be further processed by the consuming application
@@ -75,54 +77,6 @@ You can also pass an array of targets to ensure compatibility across multiple en
 tsdown --target chrome100 --target node20.18
 ```
 
-## Runtime Helpers
-
-When downleveling certain modern JavaScript features, `tsdown` may require runtime helpers provided by the `@oxc-project/runtime` package. For example, transforming `await` expressions into older syntax requires the helper `@oxc-project/runtime/helpers/asyncToGenerator`.
-
-If your target includes features that require these helpers, you may need to install the `@oxc-project/runtime` package in your project:
-
-::: code-group
-
-```sh [npm]
-npm install @oxc-project/runtime
-```
-
-```sh [pnpm]
-pnpm add @oxc-project/runtime
-```
-
-```sh [yarn]
-yarn add @oxc-project/runtime
-```
-
-```sh [bun]
-bun add @oxc-project/runtime
-```
-
-:::
-
-If you want to **inline helper functions** instead of importing them from the runtime package, you can install `@oxc-project/runtime` as a development dependency:
-
-::: code-group
-
-```sh [npm]
-npm install -D @oxc-project/runtime
-```
-
-```sh [pnpm]
-pnpm add -D @oxc-project/runtime
-```
-
-```sh [yarn]
-yarn add -D @oxc-project/runtime
-```
-
-```sh [bun]
-bun add -D @oxc-project/runtime
-```
-
-:::
-
 # CSS Targeting
 
 `tsdown` can also downlevel CSS features to match your specified browser targets. For example, a CSS nesting `&` selector will be flattened if the target is `chrome108` or lower.

docs/zh-CN/options/target.md

@@ -36,12 +36,14 @@
 ```
 
 当 `target` 设置为 `false` 时：
+
 - 不会进行 JavaScript 语法降级（现代特性如可选链 `?.`、空值合并 `??` 等会被保留）
 - 不会应用 CSS 语法转换（现代 CSS 特性如嵌套会被保留）
 - 不会加载运行时辅助插件
 - 输出将使用源代码中的确切语法
 
 这在以下情况下特别有用：
+
 - 您的目标是支持最新 JavaScript/CSS 特性的现代环境
 - 您希望在不同的构建步骤中处理语法转换
 - 您正在构建一个将由使用应用程序进一步处理的库
@@ -75,54 +77,6 @@ tsdown --target es2020
 tsdown --target chrome100 --target node20.18
 ```
 
-## 运行时辅助工具
-
-在降级某些现代 JavaScript 特性时，`tsdown` 可能需要由 `@oxc-project/runtime` 包提供的运行时辅助工具。例如，将 `await` 表达式转换为旧语法时，需要使用辅助工具 `@oxc-project/runtime/helpers/asyncToGenerator`。
-
-如果您的目标环境包含需要这些辅助工具的特性，您可能需要在项目中安装 `@oxc-project/runtime` 包：
-
-::: code-group
-
-```sh [npm]
-npm install @oxc-project/runtime
-```
-
-```sh [pnpm]
-pnpm add @oxc-project/runtime
-```
-
-```sh [yarn]
-yarn add @oxc-project/runtime
-```
-
-```sh [bun]
-bun add @oxc-project/runtime
-```
-
-:::
-
-如果您希望**内联辅助函数**，而不是从运行时包中导入它们，可以将 `@oxc-project/runtime` 作为开发依赖进行安装：
-
-::: code-group
-
-```sh [npm]
-npm install -D @oxc-project/runtime
-```
-
-```sh [pnpm]
-pnpm add -D @oxc-project/runtime
-```
-
-```sh [yarn]
-yarn add -D @oxc-project/runtime
-```
-
-```sh [bun]
-bun add -D @oxc-project/runtime
-```
-
-:::
-
 # CSS 目标
 
 `tsdown` 也可以将 CSS 特性降级以匹配您指定的浏览器目标。例如，如果目标是 `chrome108` 或更低版本，CSS 嵌套的 `&` 选择器将被展开为平铺结构。

src/features/rolldown.ts

@@ -15,7 +15,6 @@ import { resolveChunkAddon, resolveChunkFilename } from './output'
 import { ReportPlugin } from './report'
 import { ShebangPlugin } from './shebang'
 import { getShimsInject } from './shims'
-import { RuntimeHelperCheckPlugin } from './target'
 import type {
   BuildOptions,
   InputOptions,
@@ -128,7 +127,6 @@ export async function resolveInputOptions(
     }
     if (target) {
       plugins.push(
-        RuntimeHelperCheckPlugin(logger, target),
         // Use Lightning CSS to handle CSS input. This is a temporary solution
         // until Rolldown supports CSS syntax lowering natively.
         await LightningCSSPlugin({ target }),

src/features/target.ts

@@ -1,9 +1,7 @@
-import { blue } from 'ansis'
 import minVersion from 'semver/ranges/min-version.js'
 import { resolveComma, toArray } from '../utils/general'
 import { generateColor, prettyName, type Logger } from '../utils/logger'
 import type { PackageJson } from 'pkg-types'
-import type { Plugin } from 'rolldown'
 
 export function resolveTarget(
   logger: Logger,
@@ -38,34 +36,3 @@ export function resolvePackageTarget(pkg?: PackageJson): string | undefined {
   if (nodeMinVersion.version === '0.0.0') return
   return `node${nodeMinVersion.version}`
 }
-
-let warned = false
-export function RuntimeHelperCheckPlugin(
-  logger: Logger,
-  targets: string[],
-): Plugin {
-  return {
-    name: 'tsdown:runtime-helper-check',
-    resolveId: {
-      filter: { id: /^@oxc-project\/runtime/ },
-      async handler(id, ...args) {
-        const EXTERNAL = { id, external: true }
-        if (warned) return EXTERNAL
-
-        const resolved = await this.resolve(id, ...args)
-        if (!resolved) {
-          if (!warned) {
-            warned = true
-            logger.warn(
-              `The target environment (${targets.join(', ')}) requires runtime helpers from ${blue`@oxc-project/runtime`}. ` +
-                `Please install it to ensure all necessary polyfills are included.\n` +
-                `For more information, visit: https://tsdown.dev/options/target#runtime-helpers`,
-            )
-          }
-          return EXTERNAL
-        }
-        return resolved
-      },
-    },
-  }
-}