perf(snapshot): minify snapshot sources

.github/workflows/ci.generated.yml

@@ -234,6 +234,8 @@ jobs:
         run: ./tools/install_prebuilt.js wrk hyperfine
       - name: Build deno
         if: '(contains(github.event.pull_request.labels.*.name, ''ci-bench'') || github.ref == ''refs/heads/main'') && !startsWith(github.ref, ''refs/tags/'')'
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: cargo build --release -p deno
       - name: Run benchmarks
         if: '(contains(github.event.pull_request.labels.*.name, ''ci-bench'') || github.ref == ''refs/heads/main'') && !startsWith(github.ref, ''refs/tags/'')'
@@ -759,6 +761,8 @@ jobs:
         run: echo "DENO_CANARY=true" >> $GITHUB_ENV
       - name: Build release
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && github.repository == ''denoland/deno'''
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: |-
           df -h
           cargo build --release --locked -p deno -p denort -p test_server --bin deno --bin denort --bin test_server --features=deno/panic-trace
@@ -1766,6 +1770,8 @@ jobs:
         run: echo "DENO_CANARY=true" >> $GITHUB_ENV
       - name: Build release
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && github.repository == ''denoland/deno'''
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: |-
           df -h
           cargo build --release --locked -p deno -p denort -p test_server --bin deno --bin denort --bin test_server --features=deno/panic-trace
@@ -2627,6 +2633,11 @@ jobs:
       - name: Clone submodule ./tests/util/std
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'')'
         run: git submodule update --init --recursive --depth=1 -- ./tests/util/std
+      - name: Install Deno
+        uses: denoland/setup-deno@667a34cdef165d8d2b2e98dde39547c9daac7282
+        if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && github.repository == ''denoland/deno'''
+        with:
+          deno-version: v2.x
       - name: Restore cache cargo home
         uses: actions/cache/restore@0057852bfaa89a56745cba8c7296529d2fc39830
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && !startsWith(github.ref, ''refs/tags/'')'
@@ -2703,6 +2714,8 @@ jobs:
         run: echo "DENO_CANARY=true" >> $GITHUB_ENV
       - name: Build release
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && github.repository == ''denoland/deno'''
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: |-
           df -h
           cargo build --release --locked -p deno -p denort -p test_server --bin deno --bin denort --bin test_server --features=deno/panic-trace
@@ -3447,6 +3460,11 @@ jobs:
       - name: Clone submodule ./tests/util/std
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'')'
         run: git submodule update --init --recursive --depth=1 -- ./tests/util/std
+      - name: Install Deno
+        uses: denoland/setup-deno@667a34cdef165d8d2b2e98dde39547c9daac7282
+        if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && github.repository == ''denoland/deno'''
+        with:
+          deno-version: v2.x
       - name: Restore cache cargo home
         uses: actions/cache/restore@0057852bfaa89a56745cba8c7296529d2fc39830
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && !startsWith(github.ref, ''refs/tags/'')'
@@ -3523,6 +3541,8 @@ jobs:
         run: echo "DENO_CANARY=true" >> $GITHUB_ENV
       - name: Build release
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && github.repository == ''denoland/deno'''
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: |-
           df -h
           cargo build --release --locked -p deno -p denort -p test_server --bin deno --bin denort --bin test_server --features=deno/panic-trace
@@ -3919,6 +3939,10 @@ jobs:
           mkdir -p target/release
           tar --exclude=".git*" --exclude=target --exclude=third_party/prebuilt \
               -czvf target/release/deno_src.tar.gz -C .. deno
+      - name: Install Deno
+        uses: denoland/setup-deno@667a34cdef165d8d2b2e98dde39547c9daac7282
+        with:
+          deno-version: v2.x
       - name: Restore cache cargo home
         uses: actions/cache/restore@0057852bfaa89a56745cba8c7296529d2fc39830
         if: '!startsWith(github.ref, ''refs/tags/'')'
@@ -4085,6 +4109,8 @@ jobs:
         if: '!startsWith(github.ref, ''refs/tags/'')'
         run: echo "DENO_CANARY=true" >> $GITHUB_ENV
       - name: Build release
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: |-
           df -h
           cargo build --release --locked -p deno -p denort -p test_server --bin deno --bin denort --bin test_server --features=deno/panic-trace
@@ -5862,6 +5888,11 @@ jobs:
       - name: Clone submodule ./tests/util/std
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'')'
         run: git submodule update --init --recursive --depth=1 -- ./tests/util/std
+      - name: Install Deno
+        uses: denoland/setup-deno@667a34cdef165d8d2b2e98dde39547c9daac7282
+        if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'')'
+        with:
+          deno-version: v2.x
       - name: Restore cache cargo home
         uses: actions/cache/restore@0057852bfaa89a56745cba8c7296529d2fc39830
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'') && !startsWith(github.ref, ''refs/tags/'')'
@@ -6034,6 +6065,8 @@ jobs:
         run: echo "DENO_CANARY=true" >> $GITHUB_ENV
       - name: Build release
         if: '!(!contains(github.event.pull_request.labels.*.name, ''ci-full'') && github.event_name == ''pull_request'')'
+        env:
+          DENO_SNAPSHOT_MINIFY_SOURCES: '1'
         run: |-
           df -h
           cargo build --release --locked -p deno -p denort -p test_server --bin deno --bin denort --bin test_server --features=deno/panic-trace

.github/workflows/ci.ts

@@ -874,6 +874,7 @@ const buildJobs = buildItems.map((rawBuildItem) => {
           )
           .dependsOn(
             installLldStep,
+            installDenoStep,
             restoreCacheStep,
             installRustStep,
             sysRootStep,
@@ -886,6 +887,9 @@ const buildJobs = buildItems.map((rawBuildItem) => {
             },
             {
               name: "Build release",
+              env: {
+                DENO_SNAPSHOT_MINIFY_SOURCES: "1",
+              },
               run: [
                 // output fs space before and after building
                 "df -h",
@@ -1474,6 +1478,9 @@ const benchJob = job(
         // we could optimize this to not need this.
         {
           name: "Build deno",
+          env: {
+            DENO_SNAPSHOT_MINIFY_SOURCES: "1",
+          },
           run: "cargo build --release -p deno",
         },
         {

cli/snapshot/build.rs

@@ -9,6 +9,7 @@ fn main() {
   #[allow(clippy::print_stdout, reason = "build script output")]
   {
     println!("cargo:rerun-if-env-changed=DENO_SNAPSHOT_IMPORT_GRAPH");
+    println!("cargo:rerun-if-env-changed=DENO_SNAPSHOT_MINIFY_SOURCES");
   }
   #[cfg(not(feature = "disable"))]
   {
@@ -51,6 +52,8 @@ fn create_cli_snapshot(
   let out_dir = std::path::PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
   let residual_sources_dir = out_dir.join("residual_sources");
   std::fs::create_dir_all(&residual_sources_dir).unwrap();
+  let minify_sources =
+    std::env::var_os("DENO_SNAPSHOT_MINIFY_SOURCES").is_some();
 
   let mut residual_js: Vec<(&str, std::path::PathBuf)> = Vec::new();
   let mut residual_esm: Vec<(&str, std::path::PathBuf)> = Vec::new();
@@ -73,6 +76,7 @@ fn create_cli_snapshot(
       &residual_sources_dir,
       &file.specifier,
       &file.path,
+      minify_sources,
     );
     match file.kind {
       LazyExtensionFileKind::Js => {
@@ -109,9 +113,11 @@ fn transpile_residual_source(
   out_dir: &std::path::Path,
   specifier: &str,
   src_path: &std::path::Path,
+  minify: bool,
 ) -> std::path::PathBuf {
   use deno_runtime::deno_core::ModuleCodeString;
   use deno_runtime::deno_core::ModuleName;
+  use deno_runtime::transpile::maybe_transpile_and_minify_source;
   use deno_runtime::transpile::maybe_transpile_source;
 
   let source = std::fs::read_to_string(src_path).unwrap_or_else(|e| {
@@ -120,10 +126,13 @@ fn transpile_residual_source(
       src_path.display()
     )
   });
-  let (transpiled, _source_map) = maybe_transpile_source(
-    ModuleName::from(specifier.to_string()),
-    ModuleCodeString::from(source),
-  )
+  let name = ModuleName::from(specifier.to_string());
+  let source = ModuleCodeString::from(source);
+  let (transpiled, _source_map) = if minify {
+    maybe_transpile_and_minify_source(name, source)
+  } else {
+    maybe_transpile_source(name, source)
+  }
   .unwrap_or_else(|e| {
     panic!("failed to transpile residual lazy source {specifier}: {e}")
   });

runtime/snapshot.rs

@@ -102,14 +102,20 @@ pub fn create_runtime_snapshot(
   extensions.extend(custom_extensions);
 
   let lazy_extension_files = collect_lazy_extension_files(&extensions);
+  let minify_sources =
+    std::env::var_os("DENO_SNAPSHOT_MINIFY_SOURCES").is_some();
 
   let output = create_snapshot(
     CreateSnapshotOptions {
       cargo_manifest_dir: env!("CARGO_MANIFEST_DIR"),
       startup_snapshot: None,
       extensions,
-      extension_transpiler: Some(Rc::new(|specifier, source| {
-        crate::transpile::maybe_transpile_source(specifier, source)
+      extension_transpiler: Some(Rc::new(move |specifier, source| {
+        if minify_sources {
+          crate::transpile::maybe_transpile_and_minify_source(specifier, source)
+        } else {
+          crate::transpile::maybe_transpile_source(specifier, source)
+        }
       })),
       with_runtime_cb: Some(Box::new(|rt| {
         let isolate = rt.v8_isolate();

runtime/transpile.rs

@@ -1,6 +1,8 @@
 // Copyright 2018-2026 the Deno authors. MIT license.
 
+use std::io::Write;
 use std::path::Path;
+use std::sync::OnceLock;
 
 use deno_ast::MediaType;
 use deno_ast::ParseParams;
@@ -25,6 +27,22 @@ pub fn maybe_transpile_source(
   name: ModuleName,
   source: ModuleCodeString,
 ) -> Result<(ModuleCodeString, Option<SourceMapData>), JsErrorBox> {
+  maybe_transpile_source_inner(name, source, false)
+}
+
+pub fn maybe_transpile_and_minify_source(
+  name: ModuleName,
+  source: ModuleCodeString,
+) -> Result<(ModuleCodeString, Option<SourceMapData>), JsErrorBox> {
+  maybe_transpile_source_inner(name, source, true)
+}
+
+fn maybe_transpile_source_inner(
+  name: ModuleName,
+  source: ModuleCodeString,
+  minify: bool,
+) -> Result<(ModuleCodeString, Option<SourceMapData>), JsErrorBox> {
+  let name_string = name.to_string();
   // Always transpile `node:` built-in modules, since they might be TypeScript.
   let media_type = if name.starts_with("node:") {
     MediaType::TypeScript
@@ -34,8 +52,14 @@ pub fn maybe_transpile_source(
 
   match media_type {
     MediaType::TypeScript => {}
-    MediaType::JavaScript => return Ok((source, None)),
-    MediaType::Mjs => return Ok((source, None)),
+    MediaType::JavaScript | MediaType::Mjs => {
+      if minify {
+        let source =
+          minify_source_with_rolldown(&name_string, source.as_ref())?;
+        return Ok((source.into(), None));
+      }
+      return Ok((source, None));
+    }
     _ => panic!(
       "Unsupported media type for snapshotting {media_type:?} for file {}",
       name
@@ -74,5 +98,111 @@ pub fn maybe_transpile_source(
     .source_map
     .map(|sm| sm.into_bytes().into());
   let source_text = transpiled_source.text;
-  Ok((source_text.into(), maybe_source_map))
+  if minify {
+    let source_text = minify_source_with_rolldown(&name_string, &source_text)?;
+    Ok((source_text.into(), None))
+  } else {
+    Ok((source_text.into(), maybe_source_map))
+  }
+}
+
+#[allow(
+  clippy::disallowed_methods,
+  reason = "snapshot source minification runs at build time"
+)]
+fn minify_source_with_rolldown(
+  specifier: &str,
+  source: &str,
+) -> Result<String, JsErrorBox> {
+  static MINIFIER_PATH: OnceLock<std::path::PathBuf> = OnceLock::new();
+  let minifier_path = MINIFIER_PATH.get_or_init(|| {
+    let path =
+      std::env::temp_dir().join("deno_snapshot_rolldown_minify_source.js");
+    std::fs::write(
+      &path,
+      r#"import { minifySync } from "npm:rolldown/experimental";
+
+const filename = Deno.args[0] ?? "source.js";
+const source = await new Response(Deno.stdin.readable).text();
+const result = minifySync(filename, source, {
+  compress: false,
+  mangle: false,
+  codegen: {
+    removeWhitespace: true,
+    legalComments: "none",
+  },
+});
+if (result.errors?.length) {
+  console.error(JSON.stringify(result.errors, null, 2));
+  Deno.exit(1);
+}
+function escapeNonAscii(code) {
+  let out = "";
+  for (let i = 0; i < code.length; i++) {
+    const unit = code.charCodeAt(i);
+    if (unit <= 0x7f) {
+      out += code[i];
+    } else {
+      out += "\\u" + unit.toString(16).padStart(4, "0");
+    }
+  }
+  return out;
+}
+const output = new TextEncoder().encode(escapeNonAscii(result.code));
+let offset = 0;
+while (offset < output.length) {
+  offset += await Deno.stdout.write(output.subarray(offset));
+}
+"#,
+    )
+    .unwrap();
+    path
+  });
+
+  let mut child = std::process::Command::new("deno")
+    .arg("run")
+    .arg("-A")
+    .arg(minifier_path)
+    .arg(specifier)
+    .stdin(std::process::Stdio::piped())
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::piped())
+    .spawn()
+    .map_err(|e| {
+      JsErrorBox::generic(format!(
+        "failed to run rolldown source minifier for {specifier}: {e}"
+      ))
+    })?;
+  child
+    .stdin
+    .as_mut()
+    .unwrap()
+    .write_all(source.as_bytes())
+    .map_err(|e| {
+      JsErrorBox::generic(format!(
+        "failed to write source to rolldown minifier for {specifier}: {e}"
+      ))
+    })?;
+  let output = child.wait_with_output().map_err(|e| {
+    JsErrorBox::generic(format!(
+      "failed to wait for rolldown source minifier for {specifier}: {e}"
+    ))
+  })?;
+  if !output.status.success() {
+    return Err(JsErrorBox::generic(format!(
+      "failed to minify source {specifier}\nstdout:\n{}\nstderr:\n{}",
+      String::from_utf8_lossy(&output.stdout),
+      String::from_utf8_lossy(&output.stderr),
+    )));
+  }
+  let output = String::from_utf8(output.stdout).map_err(|e| {
+    JsErrorBox::generic(format!(
+      "rolldown minifier produced non-utf8 output for {specifier}: {e}"
+    ))
+  })?;
+  assert!(
+    output.is_ascii(),
+    "rolldown minifier produced non-ascii output for {specifier}"
+  );
+  Ok(output)
 }