feat: support `ModuleType:Copy` by hyf0 · Pull Request #8407 · rolldown/rolldown

hyf0 · 2026-02-21T09:34:37Z

Summary

Adds ModuleType::Copy — a new module type that copies assets (images, fonts, binaries, etc.) to the output directory and rewrites imports to point at the emitted file.

Configure via moduleTypes:

export default {
  moduleTypes: {
    '.png': 'copy',
    '.woff2': 'copy',
  }
}

How it works

The implementation lives in a new builtin plugin (rolldown_plugin_copy_module) that operates in two phases:

Phase 1: `resolve_id`

When rolldown encounters an import like import img from './photo.png':

Resolves the specifier to an absolute path
Checks if the extension is registered as a copy module type
Reads the file bytes and emits them as an asset via ctx.emit_file_async() — the FileEmitter hashes the content with XXH3-128 and generates a filename from the configured assetFileNames template (default: assets/[name]-[hash][extname])
Returns a prefixed placeholder ID (__ROLLDOWN_COPY_MODULE__#<reference_id>) marked as external: true

Marking external is the key trick — rolldown won't try to parse or bundle the file, just emit an import statement with the placeholder string.

Phase 2: `render_chunk`

After chunk code is generated (containing import img from "__ROLLDOWN_COPY_MODULE__#ref123"):

Uses memchr::memmem for SIMD-accelerated search of all placeholder positions
Resolves each reference ID to the final asset filename via ctx.get_file_name()
Computes the relative path from the chunk to the asset
Replaces the placeholder with the real path via MagicString

Result: import img from "./assets/photo-4dj8Fk2L.png"

Changes

crates/rolldown_plugin_copy_module/ — new builtin plugin crate
crates/rolldown_common/.../module_type.rs — adds ModuleType::Copy variant
crates/rolldown/src/utils/apply_inner_plugins.rs — registers the plugin when copy extensions are configured
crates/rolldown/src/utils/load_source.rs — handles Copy module type in the load phase
crates/rolldown/src/utils/parse_to_ecma_ast.rs — treats Copy modules as empty JS (they're externalized by the plugin)
packages/rolldown/src/options/input-options.ts — adds 'copy' to the ModuleType union
Tests — two integration tests: basic copy and nested path resolution

🤖 Generated with Claude Code

Closes #6411

hyf0 · 2026-02-21T09:34:51Z

feat: support ModuleType:Copy #8407 👈 (View in Graphite)
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netlify · 2026-02-21T09:35:50Z

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crates/rolldown/src/utils/load_source.rs

Copilot

Pull request overview

Adds a new ModuleType::Copy loader to Rolldown (aligned with esbuild “copy” semantics) by introducing a builtin plugin that emits matched modules as assets and rewrites import/require specifiers to the emitted asset paths.

Changes:

Extend TS and Rust option/type validation to accept "copy" as a module type.
Introduce rolldown_plugin_copy_module and wire it into Rolldown’s builtin plugin pipeline when configured.
Add integration tests + snapshot updates covering basic and nested-path copy-module scenarios.

Reviewed changes

Copilot reviewed 21 out of 22 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
packages/rolldown/src/utils/validator.ts	Allows `"copy"` in moduleTypes validation.
packages/rolldown/src/options/input-options.ts	Extends `ModuleTypes` union to include `"copy"`.
crates/rolldown_testing/_config.schema.json	Updates JSON schema enum to include `"copy"`.
crates/rolldown_plugin_copy_module/src/lib.rs	New builtin plugin: resolves copy-modules, emits assets, rewrites chunk code.
crates/rolldown_plugin_copy_module/Cargo.toml	Adds new plugin crate manifest.
crates/rolldown_common/src/inner_bundler_options/types/module_type.rs	Adds `ModuleType::Copy` + string conversions/display.
crates/rolldown/src/utils/parse_to_ecma_ast.rs	Errors if `Copy` reaches parsing stage (should be intercepted by plugin).
crates/rolldown/src/utils/load_source.rs	Errors if `Copy` reaches file loading stage (should be intercepted by plugin).
crates/rolldown/src/utils/apply_inner_plugins.rs	Registers the copy-module plugin when `moduleTypes` includes `copy`.
crates/rolldown/Cargo.toml	Adds dependency on the new plugin crate.
Cargo.toml / Cargo.lock	Wires new crate into workspace deps/lockfile.
crates/rolldown/tests/**	Adds new copy-module fixtures and snapshot expectations.

crates/rolldown/src/utils/parse_to_ecma_ast.rs

crates/rolldown_plugin_copy_module/src/lib.rs

crates/rolldown/src/utils/load_source.rs

github-actions · 2026-02-21T09:52:27Z

Benchmarks Rust

target: main(6c8834b)
pr: 02-21-feat_support_moduletype_copy_(e3b4aea)

group                                                        pr                                     target
-----                                                        --                                     ------
bundle/bundle@multi-duplicated-top-level-symbol              1.00     72.3±1.99ms        ? ?/sec    1.02     73.5±4.10ms        ? ?/sec
bundle/bundle@multi-duplicated-top-level-symbol-sourcemap    1.04     80.4±2.98ms        ? ?/sec    1.00     77.2±3.12ms        ? ?/sec
bundle/bundle@rome_ts                                        1.01    104.6±4.02ms        ? ?/sec    1.00    103.3±2.51ms        ? ?/sec
bundle/bundle@rome_ts-sourcemap                              1.00    115.5±2.39ms        ? ?/sec    1.00    115.9±3.15ms        ? ?/sec
bundle/bundle@threejs                                        1.05     37.3±0.66ms        ? ?/sec    1.00     35.5±2.22ms        ? ?/sec
bundle/bundle@threejs-sourcemap                              1.01     41.7±0.98ms        ? ?/sec    1.00     41.2±1.10ms        ? ?/sec
bundle/bundle@threejs10x                                     1.02    372.0±7.32ms        ? ?/sec    1.00    365.1±6.55ms        ? ?/sec
bundle/bundle@threejs10x-sourcemap                           1.04    430.4±7.80ms        ? ?/sec    1.00    413.4±3.52ms        ? ?/sec
scan/scan@rome_ts                                            1.00     78.4±1.55ms        ? ?/sec    1.01     79.4±2.16ms        ? ?/sec
scan/scan@threejs                                            1.01     28.2±1.70ms        ? ?/sec    1.00     27.9±1.67ms        ? ?/sec
scan/scan@threejs10x                                         1.00    283.4±5.09ms        ? ?/sec    1.00    284.1±7.83ms        ? ?/sec

hyf0 · 2026-02-21T12:00:39Z

Merge activity

Feb 21, 12:00 PM UTC: The merge label 'graphite: merge-when-ready' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Feb 21, 12:00 PM UTC: hyf0 added this pull request to the Graphite merge queue.
Feb 21, 12:05 PM UTC: The Graphite merge queue couldn't merge this PR because it was not satisfying all requirements (Failed CI: 'cargo-test (ubuntu-latest) / Cargo Test', 'cargo-test (macos-latest) / Cargo Test', 'cargo-test (windows-latest) / Cargo Test').
Feb 21, 12:06 PM UTC: The merge label 'graphite: merge-when-ready' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Feb 21, 12:06 PM UTC: The merge label 'graphite: merge-when-ready' was removed. This PR will no longer be merged by the Graphite merge queue
Feb 21, 2:24 PM UTC: The merge label 'graphite: merge-when-ready' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Feb 21, 2:24 PM UTC: hyf0 added this pull request to the Graphite merge queue.
Feb 21, 2:25 PM UTC: Merged by the Graphite merge queue.

## Summary Adds `ModuleType::Copy` — a new module type that copies assets (images, fonts, binaries, etc.) to the output directory and rewrites imports to point at the emitted file. Configure via `moduleTypes`: ```js export default { moduleTypes: { '.png': 'copy', '.woff2': 'copy', } } ``` ## How it works The implementation lives in a new builtin plugin (`rolldown_plugin_copy_module`) that operates in two phases: ### Phase 1: `resolve_id` When rolldown encounters an import like `import img from './photo.png'`: 1. Resolves the specifier to an absolute path 2. Checks if the extension is registered as a copy module type 3. Reads the file bytes and emits them as an asset via `ctx.emit_file_async()` — the `FileEmitter` hashes the content with XXH3-128 and generates a filename from the configured `assetFileNames` template (default: `assets/[name]-[hash][extname]`) 4. Returns a prefixed placeholder ID (`__ROLLDOWN_COPY_MODULE__#<reference_id>`) marked as `external: true` Marking external is the key trick — rolldown won't try to parse or bundle the file, just emit an import statement with the placeholder string. ### Phase 2: `render_chunk` After chunk code is generated (containing `import img from "__ROLLDOWN_COPY_MODULE__#ref123"`): 1. Uses `memchr::memmem` for SIMD-accelerated search of all placeholder positions 2. Resolves each reference ID to the final asset filename via `ctx.get_file_name()` 3. Computes the relative path from the chunk to the asset 4. Replaces the placeholder with the real path via MagicString Result: `import img from "./assets/photo-4dj8Fk2L.png"` ## Changes - **`crates/rolldown_plugin_copy_module/`** — new builtin plugin crate - **`crates/rolldown_common/.../module_type.rs`** — adds `ModuleType::Copy` variant - **`crates/rolldown/src/utils/apply_inner_plugins.rs`** — registers the plugin when copy extensions are configured - **`crates/rolldown/src/utils/load_source.rs`** — handles `Copy` module type in the load phase - **`crates/rolldown/src/utils/parse_to_ecma_ast.rs`** — treats `Copy` modules as empty JS (they're externalized by the plugin) - **`packages/rolldown/src/options/input-options.ts`** — adds `'copy'` to the `ModuleType` union - **Tests** — two integration tests: basic copy and nested path resolution 🤖 Generated with [Claude Code](https://claude.com/claude-code) Closes #6411

Copilot

Pull request overview

Copilot reviewed 22 out of 23 changed files in this pull request and generated 2 comments.

Copilot · 2026-02-21T14:31:08Z

crates/rolldown_plugin_copy_module/src/lib.rs

+  async fn render_chunk(
+    &self,
+    ctx: &PluginContext,
+    args: &HookRenderChunkArgs<'_>,
+  ) -> HookRenderChunkReturn {
+    // Quick bail: if the code doesn't contain our prefix, nothing to do
+    if !args.code.contains(PREFIX) {
+      return Ok(None);
+    }
+
+    let chunk_filename = &args.chunk.filename;
+    let code = &args.code;
+    let mut magic_string = MagicString::new(code);
+    let mut changed = false;
+
+    // Use memchr for SIMD-accelerated substring search
+    let finder = memmem::find_iter(code.as_bytes(), PREFIX.as_bytes());
+
+    for abs_pos in finder {
+      let after_prefix = abs_pos + PREFIX.len();
+
+      // Extract ref_id: scan until we hit a quote (", ') or end of string
+      let rest = &code[after_prefix..];
+      let ref_end = rest.find(['"', '\'']).unwrap_or(rest.len());
+      let ref_id = &rest[..ref_end];
+
+      if ref_id.is_empty() {
+        continue;
+      }
+
+      // Resolve the asset filename
+      let asset_filename = match ctx.get_file_name(ref_id) {
+        Ok(name) => name,
+        Err(_) => continue,
+      };
+
+      // Compute relative path from chunk to asset
+      let relative = compute_relative_path(chunk_filename, &asset_filename);
+
+      let end = after_prefix + ref_end;
+      #[expect(clippy::cast_possible_truncation)]
+      if magic_string.update(abs_pos as u32, end as u32, relative).is_ok() {
+        changed = true;
+      }
+    }


render_chunk rewrites every occurrence of the prefix in the full chunk text, without checking context (e.g. that it’s inside an import/require string literal emitted by rolldown). This means any user-authored string/comment containing the prefix would be rewritten too. To make this more robust, consider using an unambiguous sentinel with a terminator (similar to __VITE_ASSET__<ref>__) and validating the reference-id characters / surrounding delimiters before applying replacements.

Copilot · 2026-02-21T14:31:09Z

crates/rolldown_plugin_copy_module/src/lib.rs

+    // Return a prefixed external ID — the prefix will be rewritten in render_chunk
+    let placeholder_id: ArcStr = format!("{PREFIX}{reference_id}").into();
+
+    Ok(Some(HookResolveIdOutput {
+      id: placeholder_id,
+      external: Some(ResolvedExternal::Bool(true)),


Marking copy modules as external and then rewriting the import specifier in render_chunk leaves the output as import x from "./assets/foo.txt" / require("./assets/foo.txt"). That does not match existing ModuleType::Asset semantics (which bundle a JS module exporting the emitted path string) and will fail in standard JS runtimes because the copied asset isn’t a JS module. Consider generating a virtual JS module instead (e.g. resolve to a \0-prefixed id, implement load to export default import.meta.ROLLUP_FILE_URL_<refId> or similar) and let the existing asset URL rewriting machinery produce the final string path.

Suggested change

// Return a prefixed external ID — the prefix will be rewritten in render_chunk

let placeholder_id: ArcStr = format!("{PREFIX}{reference_id}").into();

Ok(Some(HookResolveIdOutput {

id: placeholder_id,

external: Some(ResolvedExternal::Bool(true)),

// Return a prefixed ID; treat it as an asset module so the bundler

// generates a JS module exporting the asset URL instead of a bare

// import of a non-JS file.

let placeholder_id: ArcStr = format!("{PREFIX}{reference_id}").into();

Ok(Some(HookResolveIdOutput {

id: placeholder_id,

// Let the bundler handle this as an asset module instead of an external.

module_type: Some(ModuleType::Asset),

external: None,

@hyf0

## [1.0.0-rc.6] - 2026-02-26 ### 💥 BREAKING CHANGES - css: remove `css_entry_filenames` , `css_chunk_filenames` and related code (#8402) by @hyf0 - css: drop builtin CSS bundling to explore alternative solutions (#8399) by @hyf0 ### 🚀 Features - rust/data-url: use hash as id for data url modules to prevent long string overhead (#8420) by @hyf0 - validate bundle stays within output dir (#8441) by @sapphi-red - rust: support `PluginOrder::PinPost` (#8417) by @hyf0 - support `ModuleType:Copy` (#8407) by @hyf0 - expose `ESTree` types from `rolldown/utils` (#8400) by @sapphi-red ### 🐛 Bug Fixes - incorrect sourcemap when postBanner/postFooter is used with shebang (#8459) by @Copilot - resolver: disable node_path option to align ESM resolver behavior (#8472) by @sapphi-red - parse `.js` within `"type": "commonjs"` as ESM for now (#8470) by @sapphi-red - case-insensitive filename conflict detection for chunk deduplication (#8458) by @Copilot - prevent inlining CJS exports that are mutated by importers (#8456) by @IWANABETHATGUY - parse `.cjs` / `.cts` / `.js` within `"type": "commonjs"` as CommonJS (#8455) by @sapphi-red - plugin/copy-module: correct hooks' priority (#8423) by @hyf0 - plugin/chunk-import-map: ensure `render_chunk_meta` run after users plugin (#8422) by @hyf0 - rust: correct hooks order of `DataUriPlugin` (#8418) by @hyf0 - `jsx.preserve` should also considering tsconfig json preserve (#8324) by @IWANABETHATGUY - `deferred_scan_data.rs "Should have resolved id: NotFound"` error (#8379) by @sapphi-red - cli: require value for `--dir`/`-d` and `--file`/`-o` (#8378) by @Copilot - dev: avoid mutex deadlock caused by inconsistent lock order (#8370) by @sapphi-red ### 🚜 Refactor - watch: rename TaskStart/TaskEnd to BundleStart/BundleEnd (#8463) by @hyf0 - rust: rename `rolldown_plugin_data_uri` to `rolldown_plugin_data_url` (#8421) by @hyf0 - bindingify-build-hook: extract helper for PluginContextImpl (#8438) by @ShroXd - give source loading a proper name (#8436) by @IWANABETHATGUY - ban holding DashMap refs across awaits (#8362) by @sapphi-red ### 📚 Documentation - add glob pattern usage example to input option (#8469) by @IWANABETHATGUY - remove `https://rolldown.rs` from links in reference docs (#8454) by @sapphi-red - mention execution order issue in `output.codeSplitting` docs (#8452) by @sapphi-red - clarify `output.comments` behavior a bit (#8451) by @sapphi-red - replace npmjs package links with npmx.dev (#8439) by @Boshen - reference: add `Exported from` for values / types exported from subpath exports (#8394) by @sapphi-red - add JSDocs for APIs exposed from subpath exports (#8393) by @sapphi-red - reference: generate reference pages for APIs exposed from subpath exports (#8392) by @sapphi-red - avoid pipe character in codeSplitting example to fix broken rendering (#8391) by @IWANABETHATGUY ### ⚡ Performance - avoid redundant PathBuf allocations in resolve paths (#8435) by @Brooooooklyn - bump to `sugar_path@2` (#8432) by @hyf0 - use flag-based convergence detection in include_statements (#8412) by @Brooooooklyn ### 🧪 Testing - execute `_test.mjs` even if `executeOutput` is false (#8398) by @sapphi-red - add retry to tree-shake/module-side-effects-proxy4 as it is flaky (#8397) by @sapphi-red - avoid `expect.assertions()` as it is not concurrent test friendly (#8383) by @sapphi-red - disable `mockReset` option (#8382) by @sapphi-red - fix flaky failure caused by concurrent resolveId calls (#8381) by @sapphi-red ### ⚙️ Miscellaneous Tasks - deps: update dependency rollup to v4.59.0 [security] (#8471) by @renovate[bot] - ai/design: add design doc about watch mode (#8453) by @hyf0 - deps: update oxc resolver to v11.19.0 (#8461) by @renovate[bot] - ai: introduce progressive spec-driven development pattern (#8446) by @hyf0 - deprecate output.legalComments (#8450) by @sapphi-red - deps: update dependency oxlint-tsgolint to v0.15.0 (#8448) by @renovate[bot] - ai: make CLAUDE.md a symlink of AGENTS.md (#8445) by @hyf0 - deps: update rollup submodule for tests to v4.59.0 (#8433) by @sapphi-red - deps: update test262 submodule for tests (#8434) by @sapphi-red - deps: update oxc to v0.115.0 (#8430) by @renovate[bot] - deps: update oxc apps (#8429) by @renovate[bot] - deps: update npm packages (#8426) by @renovate[bot] - deps: update rust crate owo-colors to v4.3.0 (#8428) by @renovate[bot] - deps: update github-actions (#8424) by @renovate[bot] - deps: update rust crates (#8425) by @renovate[bot] - deps: update oxc resolver to v11.18.0 (#8406) by @renovate[bot] - deps: update dependency oxlint-tsgolint to v0.14.2 (#8405) by @renovate[bot] - ban `expect.assertions` in all fixture tests (#8395) by @sapphi-red - deps: update oxc apps (#8389) by @renovate[bot] - ban `expect.assertions` in fixture tests (#8387) by @sapphi-red - enable lint for `_config.ts` files (#8386) by @sapphi-red - deps: update dependency oxlint-tsgolint to v0.14.1 (#8385) by @renovate[bot] Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>

github-actions bot assigned hyf0 Feb 21, 2026

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feat: support `ModuleType:Copy`#8407

feat: support `ModuleType:Copy`#8407
graphite-app[bot] merged 1 commit intomainfrom
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Phase 1: resolve_id

Phase 2: render_chunk

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Phase 1: `resolve_id`

Phase 2: `render_chunk`

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