script to make a big tree for testing large walks

.gitignore

@@ -10,3 +10,4 @@
 /coverage
 /test/fixtures
 /bench-working-dir
+/scripts/fixture

.prettierignore

@@ -7,3 +7,5 @@
 /.nyc_output
 /coverage
 /benchmark
+/scripts/fixture
+/test/fixture

package.json

@@ -69,9 +69,9 @@
     "@types/tap": "^15.0.7",
     "c8": "^7.12.0",
     "eslint-config-prettier": "^8.6.0",
-    "mkdirp": "^2.0.0",
+    "mkdirp": "^2.1.4",
     "prettier": "^2.8.3",
-    "rimraf": "^4.1.1",
+    "rimraf": "^4.1.3",
     "tap": "^16.3.4",
     "ts-node": "^10.9.1",
     "typedoc": "^0.23.24",

scripts/make-big-tree.js

@@ -0,0 +1,56 @@
+#!/usr/bin/env node
+const mkdirp = require('mkdirp')
+const { readFileSync } = require('fs')
+const { writeFile } = require('fs/promises')
+const rimraf = require('rimraf')
+const filesPerDir = 10
+const dirsPerDir = 5
+const max = (module === require.main && +process.argv[2]) || 1_000_000
+const { now } = performance
+let lastReported = now()
+
+const report = s => {
+  if (!process.stderr.isTTY) return
+  process.stderr.write('\r' + s.padEnd(40))
+}
+
+let made = 0
+const makeStep = async dir => {
+  if (now() - lastReported > 250) report('growing: ' + made)
+  const promises = []
+  for (let i = 0; i < filesPerDir && made < max; i++) {
+    made++
+    promises.push(writeFile(`${dir}/${i}.txt`, ''))
+  }
+  await Promise.all(promises)
+
+  const childDirs = []
+  for (let i = 0; i < dirsPerDir && made < max; i++) {
+    made++
+    await mkdirp(`${dir}/${i}`)
+    childDirs.push(makeStep(`${dir}/${i}`))
+  }
+  await Promise.all(childDirs)
+}
+
+const make = async root => {
+  try {
+    const already = +readFileSync(`${root}/bigtree.txt`)
+    if (already === max) {
+      console.log('already done!')
+      return
+    }
+  } catch (_) {}
+  report('chop down previous bigtree...')
+  await rimraf(root + '/bigtree')
+  report('creating bigtree...')
+  report('\n')
+  await mkdirp(root + '/bigtree')
+  await makeStep(root + '/bigtree')
+  await writeFile(`${root}/bigtree.txt`, `${max}`)
+}
+
+make(__dirname + '/fixture').then(() => {
+  if (process.stderr.isTTY) process.stderr.write('\r'.padEnd(40) + '\r')
+  console.log('done')
+})