perf(build): skip gzip for node_modules files in the size report

src/core/utils/fs-tree.ts

@@ -31,7 +31,10 @@ export async function generateFSTree(
       const path = resolve(dir, file);
       const src = await fsp.readFile(path);
       const size = src.byteLength;
-      const gzip = options.compressedSizes ? await gzipSize(src) : 0;
+      const gzip =
+        options.compressedSizes && !file.includes("node_modules")
+          ? await gzipSize(src)
+          : 0;
       items.push({ file, path, size, gzip });
     },
     { concurrency: 10 }
@@ -43,7 +46,6 @@ export async function generateFSTree(
   let totalGzip = 0;
 
   let totalNodeModulesSize = 0;
-  let totalNodeModulesGzip = 0;
 
   let treeText = "";
 
@@ -59,7 +61,6 @@ export async function generateFSTree(
 
     if (isNodeModules) {
       totalNodeModulesSize += item.size;
-      totalNodeModulesGzip += item.gzip;
       continue;
     }
 
@@ -78,7 +79,7 @@ export async function generateFSTree(
     totalSize + totalNodeModulesSize
   )}`;
   if (options.compressedSizes) {
-    treeText += ` (${prettyBytes(totalGzip + totalNodeModulesGzip)} gzip)`;
+    treeText += ` (${prettyBytes(totalGzip)} gzip${totalNodeModulesSize ? ", excluding node_modules" : ""})`;
   }
   treeText += "\n";
 

test/unit/fs-tree.test.ts

@@ -0,0 +1,57 @@
+import { mkdir, mkdtemp, realpath, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { stripVTControlCharacters } from "node:util";
+import { join } from "pathe";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { generateFSTree } from "../../src/core/utils/fs-tree";
+
+// generateFSTree prints nothing under test
+vi.mock("std-env", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("std-env")>()),
+  isTest: false,
+}));
+
+const { gzipSize } = vi.hoisted(() => ({
+  gzipSize: vi.fn(async (input: Uint8Array) => input.byteLength / 2),
+}));
+vi.mock("gzip-size", () => ({ gzipSize }));
+
+describe("generateFSTree", () => {
+  let dir: string;
+
+  beforeEach(async () => {
+    gzipSize.mockClear();
+    dir = await realpath(await mkdtemp(join(tmpdir(), "nitro-fs-tree-")));
+    await writeFile(join(dir, "index.mjs"), "a".repeat(1000));
+  });
+
+  afterEach(async () => {
+    await rm(dir, { recursive: true, force: true });
+  });
+
+  async function tree() {
+    return stripVTControlCharacters(
+      (await generateFSTree(dir, { compressedSizes: true })) || ""
+    );
+  }
+
+  it("reports gzip sizes of the listed files", async () => {
+    const text = await tree();
+
+    expect(text).toContain("index.mjs (1 kB) (500 B gzip)");
+    expect(text).toContain("Σ Total size: 1 kB (500 B gzip)\n");
+  });
+
+  it("does not gzip node_modules files", async () => {
+    await mkdir(join(dir, "node_modules/dep"), { recursive: true });
+    await writeFile(join(dir, "node_modules/dep/index.js"), "b".repeat(3000));
+
+    const text = await tree();
+
+    expect(gzipSize).toHaveBeenCalledTimes(1);
+    expect(text).not.toContain("node_modules/dep");
+    expect(text).toContain(
+      "Σ Total size: 4 kB (500 B gzip, excluding node_modules)\n"
+    );
+  });
+});