fix: prevent duplicating config.test entries

[AriPerkkio]

• Fixes Duplicate text-summary or text coverage report vitest-dev/vitest#3439

Do not duplicate config.test entries on config plugin hook. Vite will merge these and the user provided configurations are duplicated.

Minimal reproduction:

import { defineConfig } from "vitest/config";
import solidPlugin from "vite-plugin-solid";

export default defineConfig({
  plugins: [
    solidPlugin({}),
    {
      name: "log-config",
      enforce: "post",
      config(config) {
        console.log("config.test", config.test);
        console.log("config.esbuild", config.esbuild);
      },
    },
  ],

  esbuild: {
    include: [/\.js$/], // Just to demonstrate that this is also merged automatically
  },

  test: {
    reporters: ["verbose", "hanging-process"],
    coverage: {
      reporter: ["text-summary"],
    },
  },
});

Without fix, see how config.test is duplicated. Also note how config.esbuild is automatically merged even when this plugin does not merge those manually:

config.test {
  reporters: [ 'verbose', 'hanging-process', 'verbose', 'hanging-process' ],
  coverage: { reporter: [ 'text-summary', 'text-summary' ] },
  globals: true,
  environment: 'jsdom',
  transformMode: { web: [ /\.[jt]sx?$/ ] },
  deps: { registerNodeLoader: true }
}
config.esbuild {
  include: [ /\.js$/, /\.ts$/ ],
  sourcemap: 'external',
  legalComments: 'inline'
}

With fix:

config.test {
  reporters: [ 'verbose', 'hanging-process' ],
  coverage: { reporter: [ 'text-summary' ] },
  globals: true,
  environment: 'jsdom',
  transformMode: { web: [ /\.[jt]sx?$/ ] },
  deps: { registerNodeLoader: true }
}
config.esbuild {
  include: [ /\.js$/, /\.ts$/ ],
  sourcemap: 'external',
  legalComments: 'inline'
}

[GitMurf]

Oh my gosh I think I finally found my problem!! This has been driving me nuts for a while now but all my unit tests are running twice when I have the vite solid plugin enabled. @AriPerkkio is this likely the same issue?

Details: when using vitest, whenever I have the vite solid plugin enabled, all my unit tests (whether the tests use solidjs or not) run twice! It is super odd and frustrating that I cannot get to the bottom of it.

See here: #112 (comment)

cc @ryansolid is there any way we can get this PR merged? 🙏 Thanks!

[GitMurf]

Thank you!

[jtmueller]

This PR definitely caused bug #120