`.cts` files are not transpiled by esbuild plugin in SSR mode

[u1f992]

Describe the bug

When dynamically importing a .cts file containing TypeScript-specific syntax in SSR mode, Vite fails to transpile it with esbuild and passes it directly to Rollup, causing a parse error.

The issue is in packages/vite/src/node/plugins/esbuild.ts:

The esbuildPlugin filter:

const filter = createFilter(include || /\.(m?ts|[jt]sx)$/, exclude || /\.js$/)

This regex /\.(m?ts|[jt]sx)$/ matches .ts, .mts, .tsx, .jsx but not .cts.

However, transformWithEsbuild already handles .cts correctly:

if (ext === 'cjs' || ext === 'mjs') {
  loader = 'js'
} else if (ext === 'cts' || ext === 'mts') {
  loader = 'ts'
}

Suggested fix:

- const filter = createFilter(include || /\.(m?ts|[jt]sx)$/, exclude || /\.js$/)
+ const filter = createFilter(include || /\.([cm]?ts|[jt]sx)$/, exclude || /\.js$/)

Reproduction

https://github.com/u1f992/vite-cts-repro

Steps to reproduce

npm install
npm test

System Info

System:
    OS: Linux 6.14 Ubuntu 24.04.3 LTS 24.04.3 LTS (Noble Numbat)
    CPU: (14) x64 Intel(R) Core(TM) Ultra 7 155U
    Memory: 22.07 GB / 30.86 GB
    Container: Yes
    Shell: 5.2.21 - /bin/bash
  Binaries:
    Node: 22.20.0 - /run/user/1000/fnm_multishells/783550_1766368436272/bin/node
    Yarn: 1.22.22 - /run/user/1000/fnm_multishells/783550_1766368436272/bin/yarn
    npm: 11.6.2 - /run/user/1000/fnm_multishells/783550_1766368436272/bin/npm
    pnpm: 10.22.0 - /run/user/1000/fnm_multishells/783550_1766368436272/bin/pnpm
  Browsers:
    Chrome: 143.0.7499.109
    Firefox: 146.0.1
    Firefox Developer Edition: 146.0.1
  npmPackages:
    vite: ^7.3.0 => 7.3.0

Used Package Manager

npm

Logs

Expected: The .cts file should be transpiled by esbuild (with loader: 'ts').

Actual:

FAILED
Parse failure: Expected ',', got 'as'
At file: test.cts:2:15

This error occurs because the TypeScript-specific as const syntax was not transpiled and was passed directly to Rollup's JavaScript parser, which doesn't understand TypeScript syntax.

Validations

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• The provided reproduction is a minimal reproducible example of the bug.