move onWriteEntry to where it can do some good

Fix: #271

src/pack.ts

@@ -402,6 +402,7 @@ export class Pack
       noMtime: this.noMtime,
       mtime: this.mtime,
       prefix: this.prefix,
+      onWriteEntry: this.onWriteEntry,
     }
   }
 
@@ -412,7 +413,6 @@ export class Pack
         job.path,
         this[ENTRYOPT](job),
       )
-      this.onWriteEntry?.(e)
       return e
         .on('end', () => this[JOBDONE](job))
         .on('error', er => this.emit('error', er))

src/write-entry.ts

@@ -88,7 +88,7 @@ export class WriteEntry
   type?: EntryTypeName | 'Unsupported'
   linkpath?: string
   stat?: Stats
-  /* c8 ignore start */
+  onWriteEntry?: (entry: WriteEntry) => any
 
   #hadError: boolean = false
 
@@ -109,6 +109,7 @@ export class WriteEntry
     this.mtime = opt.mtime
     this.prefix =
       opt.prefix ? normalizeWindowsPath(opt.prefix) : undefined
+    this.onWriteEntry = opt.onWriteEntry
 
     if (typeof opt.onwarn === 'function') {
       this.on('warn', opt.onwarn)
@@ -222,6 +223,7 @@ export class WriteEntry
       this.noMtime = true
     }
 
+    this.onWriteEntry?.(this)
     this.header = new Header({
       path: this[PREFIX](this.path),
       // only apply the prefix to hard links.
@@ -618,6 +620,7 @@ export class WriteEntryTar
   ctime?: Date
   linkpath?: string
   size: number
+  onWriteEntry?: (entry: WriteEntry) => any
 
   warn(code: string, message: string | Error, data: WarnData = {}) {
     return warnMethod(this, code, message, data)
@@ -634,6 +637,7 @@ export class WriteEntryTar
     this.strict = !!opt.strict
     this.noPax = !!opt.noPax
     this.noMtime = !!opt.noMtime
+    this.onWriteEntry = opt.onWriteEntry
 
     this.readEntry = readEntry
     const { type } = readEntry
@@ -684,6 +688,7 @@ export class WriteEntryTar
     this.remain = readEntry.size
     this.blockRemain = readEntry.startBlockSize
 
+    this.onWriteEntry?.(this as unknown as WriteEntry)
     this.header = new Header({
       path: this[PREFIX](this.path),
       linkpath:

test/create.ts

@@ -1,12 +1,12 @@
-import t, { Test } from 'tap'
-import { c, list, Pack, PackSync } from '../dist/esm/index.js'
 import fs from 'fs'
+import { mkdirp } from 'mkdirp'
 import path from 'path'
 import { rimraf } from 'rimraf'
-import { mkdirp } from 'mkdirp'
+import t, { Test } from 'tap'
+import { c, list, Pack, PackSync } from '../dist/esm/index.js'
+import { spawn } from 'child_process'
 //@ts-ignore
 import mutateFS from 'mutate-fs'
-import { spawn } from 'child_process'
 import { fileURLToPath } from 'url'
 
 const isWindows = process.platform === 'win32'
@@ -288,3 +288,23 @@ t.test('must specify some files', t => {
   t.throws(() => c({}), 'no paths specified to add to archive')
   t.end()
 })
+
+t.test('transform a filename', async t => {
+  const cwd = t.testdir({
+    'README.md': 'hello, world',
+  })
+  const data = await c(
+    {
+      cwd,
+      onWriteEntry: entry => {
+        entry.path = 'bloorg.md'
+      },
+      sync: true,
+    },
+    ['README.md'],
+  ).concat()
+  t.equal(
+    data.subarray(0, 'bloorg.md'.length).toString(),
+    'bloorg.md',
+  )
+})

test/write-entry.js

@@ -59,16 +59,23 @@ t.test('100 byte filename', t => {
   const runTest = t => {
     const f =
       '100-byte-filename-cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc'
+    let entryInOWE = undefined
     const ws = new WriteEntry(f, {
       cwd: files,
       linkCache: linkCache,
       statCache: statCache,
+      onWriteEntry: self => {
+        entryInOWE = self
+        t.equal(self.path, f)
+        t.equal(self.header, undefined)
+      },
     })
 
     let out = []
     ws.on('data', c => out.push(c))
     ws.on('end', _ => {
       out = Buffer.concat(out)
+      t.equal(entryInOWE, ws)
       t.match(ws, {
         header: {
           cksumValid: true,
@@ -1103,11 +1110,22 @@ t.test('write entry from read entry', t => {
       '',
     ])
     const fileEntry = new ReadEntry(new Header(data))
-    const wetFile = new WriteEntryTar(fileEntry, { portable: true })
+    let entryInOWE = undefined
+    const wetFile = new WriteEntryTar(fileEntry, {
+      portable: true,
+      onWriteEntry: self => {
+        entryInOWE = self
+        t.equal(self.path, '$')
+        t.equal(self.header, undefined)
+      },
+    })
     const out = []
     let wetFileEnded = false
     wetFile.on('data', c => out.push(c))
-    wetFile.on('end', _ => (wetFileEnded = true))
+    wetFile.on('end', () => {
+      wetFileEnded = true
+      t.equal(entryInOWE, wetFile)
+    })
     fileEntry.end()
     t.equal(wetFileEnded, true)
     const result = Buffer.concat(out)