feat(write): accept multiple integrity algorithms (#200)

lib/content/write.js

@@ -17,9 +17,6 @@ module.exports = write
 
 async function write (cache, data, opts = {}) {
   const { algorithms, size, integrity } = opts
-  if (algorithms && algorithms.length > 1) {
-    throw new Error('opts.algorithms only supports a single algorithm for now')
-  }
 
   if (typeof size === 'number' && data.length !== size) {
     throw sizeError(size, data.length)
@@ -30,16 +27,19 @@ async function write (cache, data, opts = {}) {
     throw checksumError(integrity, sri)
   }
 
-  const tmp = await makeTmp(cache, opts)
-  try {
-    await fs.writeFile(tmp.target, data, { flag: 'wx' })
-    await moveToDestination(tmp, cache, sri, opts)
-    return { integrity: sri, size: data.length }
-  } finally {
-    if (!tmp.moved) {
-      await fs.rm(tmp.target, { recursive: true, force: true })
+  for (const algo in sri) {
+    const tmp = await makeTmp(cache, opts)
+    const hash = sri[algo].toString()
+    try {
+      await fs.writeFile(tmp.target, data, { flag: 'wx' })
+      await moveToDestination(tmp, cache, hash, opts)
+    } finally {
+      if (!tmp.moved) {
+        await fs.rm(tmp.target, { recursive: true, force: true })
+      }
     }
   }
+  return { integrity: sri, size: data.length }
 }
 
 module.exports.stream = writeStream

test/content/write.js

@@ -329,11 +329,18 @@ t.test('checks the size of stream data if opts.size provided', (t) => {
   })
 })
 
-t.test('only one algorithm for now', async t => {
+t.test('accepts multiple algorithms', async t => {
   const CACHE = t.testdir()
-  await t.rejects(() => write(CACHE, 'foo', { algorithms: [1, 2] }), {
-    message: 'opts.algorithms only supports a single algorithm for now',
-  })
+  const CONTENT = 'multiple algorithms!'
+  const { integrity } = await write(CACHE, CONTENT, { algorithms: ['sha512', 'sha1'] })
+  const cpath512 = contentPath(CACHE, integrity.sha512.toString())
+  t.ok(fs.lstatSync(cpath512).isFile(), 'sha512 content written')
+  const cpath1 = contentPath(CACHE, integrity.sha1.toString())
+  t.ok(fs.lstatSync(cpath1).isFile(), 'sha1 content written')
+  t.equal(fs.readFileSync(cpath512, 'utf8'),
+    CONTENT, 'sha512 contents are identical to inserted content')
+  t.equal(fs.readFileSync(cpath1, 'utf8'),
+    CONTENT, 'sha1 contents are identical to inserted content')
 })
 
 t.test('writes to cache with default options', t => {