Add PrintResult for doc printer (#18372)

benchmarks/print-doc-to-string.js

@@ -1,5 +1,6 @@
 import assert from "node:assert/strict";
 import fs from "node:fs/promises";
+import prettyBytes from "pretty-bytes";
 import * as prettierProduction from "../node_modules/prettier/index.mjs";
 import * as prettierDevelopment from "../src/index.js";
 import { runBenchmark } from "./utilities.js";
@@ -7,27 +8,36 @@ import { runBenchmark } from "./utilities.js";
 assert.notEqual(prettierProduction.version, prettierDevelopment.version);
 
 const text = await fs.readFile(new URL(import.meta.url), "utf8");
-// @ts-expect-error -- No types
-const doc = await prettierDevelopment.__debug.printToDoc(text, {
-  parser: "babel",
-  cursorOffset: text.indexOf("cursorOffset"),
-});
 
-const run = (prettier) =>
-  prettier.doc.printer.printDocToString(doc, { printWidth: 80, tabWidth: 2 });
+for (const size of [1, 1e1, 1e2, 1e3]) {
+  const doc = await Promise.all(
+    Array.from({ length: size }, (_, index) =>
+      // @ts-expect-error -- No types
+      prettierDevelopment.__debug.printToDoc(text, {
+        parser: "babel",
+        cursorOffset: index === 0 ? text.indexOf("cursorOffset") : undefined,
+      }),
+    ),
+  );
 
-const expected = await run(prettierProduction);
+  const run = (prettier) =>
+    prettier.doc.printer.printDocToString(doc, { printWidth: 80, tabWidth: 2 });
 
-await runBenchmark(
-  {
-    name: "printDocToString",
-    assert: (result) => assert.deepEqual(result, expected),
-  },
-  [
-    { name: "Development", prettier: prettierDevelopment },
-    { name: "Production", prettier: prettierProduction },
-  ].map(({ name, prettier }) => ({
-    name,
-    implementation: () => run(prettier),
-  })),
-);
+  const expected = await run(prettierProduction);
+
+  await runBenchmark(
+    {
+      name: `printDocToString (${size}, ${prettyBytes(text.length * size)})`,
+      assert: (result) => assert.deepEqual(result, expected),
+      warmupIterations: 1,
+      iterations: size > 5e3 ? 1 : size > 1e2 ? 2 : undefined,
+    },
+    [
+      { name: "Development", prettier: prettierDevelopment },
+      { name: "Production", prettier: prettierProduction },
+    ].map(({ name, prettier }) => ({
+      name,
+      implementation: () => run(prettier),
+    })),
+  );
+}

benchmarks/utilities.js

@@ -28,7 +28,7 @@ async function runBenchmark(options, implementations) {
 
   const { assert, ...benchOptions } = options;
 
-  const bench = new Bench(benchOptions);
+  const bench = new Bench({ throws: true, ...benchOptions });
 
   let error;