#performance

#performance.buildCache performance.buildCache

• Type:

type BuildCacheConfig =
  | boolean
  | {
      cacheDirectory?: string;
      cacheDigest?: Array<string | undefined>;
      buildDependencies?: string[];
    };

• Default: false

Enables Rsbuild persistent build cache for Rstest test builds.

import { defineConfig } from '@rstest/core';

export default defineConfig({
  performance: {
    buildCache: true,
  },
});

When enabled, Rstest applies a few Rstest-specific defaults to keep the cache stable across runs:

• cacheDirectory defaults to the node_modules/.cache/rstest-<project-name> base directory under the active project root. Rspack stores the cache data under <cacheDirectory>/<cache.name>, so projects that share the same root still get isolated caches.
• cacheDigest automatically includes Rstest runtime inputs such as command, environment name, browser-vs-node mode.
• buildDependencies automatically includes the active Rstest config file, project config files, and discovered tsconfig paths when available.

You can customize these fields to override or extend the defaults:

• cacheDirectory: override. When you provide it, Rstest uses it as the base directory; the final cache location is <cacheDirectory>/<cache.name>.
• cacheDigest: extend. Rstest keeps its own runtime digest entries and appends your custom values after them.
• buildDependencies: extend. Rstest keeps its own dependency files and appends your custom files after resolving relative paths from the active config file directory.

For example:

import { defineConfig } from '@rstest/core';

export default defineConfig({
  performance: {
    buildCache: {
      cacheDirectory: '.cache/rstest/browser',
      cacheDigest: [process.env.CUSTOM_ENV],
      buildDependencies: ['./scripts/test-env.ts'],
    },
  },
});