Add basic snapshot tests

test/all.js

@@ -10,6 +10,7 @@ async function runTests () {
   await import('./atomic.js')
   await import('./basic.js')
   await import('./core.js')
+  await import('./snapshot.js')
   await import('./streams.js')
 
   test.resume()

test/core.js

@@ -69,31 +69,6 @@ test('read and write hypercore blocks across multiple cores', async (t) => {
   await storage.close()
 })
 
-test('read and write hypercore blocks from snapshot', async (t) => {
-  const core = await createCore(t)
-  await writeBlocks(core, 2)
-
-  const snap = core.snapshot()
-  await writeBlocks(core, 2, { start: 2 })
-
-  {
-    const rx = snap.read()
-    const proms = [rx.getBlock(0), rx.getBlock(1), rx.getBlock(2)]
-    rx.tryFlush()
-    const res = await Promise.all(proms)
-    t.is(b4a.toString(res[0]), 'block0')
-    t.is(b4a.toString(res[1]), 'block1')
-    t.is(res[2], null)
-  }
-
-  {
-    const rx = core.read()
-    const p = rx.getBlock(2)
-    rx.tryFlush()
-    t.is(b4a.toString(await p), 'block2', 'sanity check: does exist in non-snapshot core')
-  }
-})
-
 test('delete hypercore block', async (t) => {
   const core = await createCore(t)
   await writeBlocks(core, 2)

test/snapshot.js

@@ -0,0 +1,157 @@
+const test = require('brittle')
+const b4a = require('b4a')
+const {
+  createCore,
+  writeBlocks,
+  readBlocks,
+  readTreeNodes,
+  getAuth,
+  getHead,
+  getDependency,
+  getHints,
+  getUserData,
+  getBitfieldPages
+} = require('./helpers')
+
+test('read and write hypercore blocks from snapshot', async (t) => {
+  const core = await createCore(t)
+  await writeBlocks(core, 2)
+
+  const snap = core.snapshot()
+  await writeBlocks(core, 2, { start: 2 })
+
+  {
+    const res = await readBlocks(snap, 3)
+    t.is(b4a.toString(res[0]), 'block0')
+    t.is(b4a.toString(res[1]), 'block1')
+    t.is(res[2], null)
+  }
+
+  {
+    const res = await readBlocks(core, 3)
+    t.is(b4a.toString(res[2]), 'block2', 'sanity check: does exist in non-snapshot core')
+  }
+})
+
+test('snapshots from atomized core do not get updated', async (t) => {
+  const core = await createCore(t)
+  const atom = core.createAtom()
+  const atomCore = core.atomize(atom)
+
+  const atomInitSnap = atomCore.snapshot()
+  const initSnap = core.snapshot()
+  t.alike(await readBlocks(initSnap, 2), [null, null], 'sanity check')
+
+  await writeBlocks(atomCore, 2)
+  const expected = [b4a.from('block0'), b4a.from('block1')]
+
+  t.alike(await readBlocks(atomInitSnap, 2), [null, null], 'init atom snap did not change')
+  t.alike(await readBlocks(initSnap, 2), [null, null], 'init snap did not change')
+
+  const atomPostWriteSnap = atomCore.snapshot()
+  const corePostWriteSnap = core.snapshot()
+
+  t.alike(await readBlocks(atomPostWriteSnap, 2), expected, 'sanity check')
+  t.alike(await readBlocks(corePostWriteSnap, 2), [null, null], 'sanity check')
+  t.alike(await readBlocks(atomInitSnap, 2), [null, null], 'init atom snap did not change')
+  t.alike(await readBlocks(initSnap, 2), [null, null], 'init  snap did not change')
+
+  await writeBlocks(atomCore, 2, { pre: 'override-' })
+  const expectedOverride = [b4a.from('override-block0'), b4a.from('override-block1')]
+  t.alike(await readBlocks(atomCore, 2), expectedOverride, 'sanity check')
+
+  t.alike(await readBlocks(atomPostWriteSnap, 2), expected, 'post-write atom snap did not change')
+  t.alike(await readBlocks(atomInitSnap, 2), [null, null], 'init atom snap did not change')
+
+  await atom.flush()
+
+  t.alike(await readBlocks(atomPostWriteSnap, 2), expected, 'prev atom snap did not change')
+  t.alike(await readBlocks(atomInitSnap, 2), [null, null], 'init atom snap did not change')
+  t.alike(await readBlocks(corePostWriteSnap, 2), [null, null], 'core post-write snap did not change')
+  t.alike(await readBlocks(initSnap, 2), [null, null], 'init snap did not change')
+
+  t.alike(await readBlocks(core, 2), expectedOverride, 'sanity check')
+})
+
+test('snapshots immutable (all operations)', async (t) => {
+  const core = await createCore(t)
+  await writeBlocks(core, 2)
+
+  const snap = core.snapshot()
+
+  {
+    await writeBlocks(core, 2, { start: 2 })
+
+    const tx = core.write()
+    tx.putTreeNode({
+      index: 0,
+      size: 1,
+      hash: b4a.from('a'.repeat(64), 'hex')
+    })
+    tx.setAuth({
+      key: b4a.alloc(32),
+      discoveryKey: b4a.alloc(32),
+      manifest: null,
+      keyPair: null,
+      encryptionKey: b4a.from('a'.repeat(64, 'hex'))
+    })
+    tx.setHead({
+      fork: 1,
+      length: 3,
+      rootHash: b4a.from('a'.repeat(64), 'hex'),
+      signature: b4a.from('b'.repeat(64), 'hex')
+    })
+    tx.setDependency({
+      dataPointer: 1,
+      length: 3
+    })
+    tx.setHints({
+      contiguousLength: 1
+    })
+    tx.putUserData('key', b4a.from('value'))
+    tx.putBitfieldPage(0, b4a.from('bitfield-data-1'))
+
+    await tx.flush()
+  }
+
+  t.alike(
+    await readBlocks(core, 4),
+    [b4a.from('block0'), b4a.from('block1'), b4a.from('block2'), b4a.from('block3')],
+    'sanity check'
+  )
+
+  t.not(await readBlocks(core, 3), [null, null, null], 'sanity check (core itself got updated')
+  t.alike(
+    await readBlocks(snap, 4),
+    [b4a.from('block0'), b4a.from('block1'), null, null],
+    'snap blocks unchanged'
+  )
+
+  t.not(await readTreeNodes(core, 2), [null, null], 'sanity check (core itself got updated)')
+  t.alike(await readTreeNodes(snap, 2), [null, null], 'tree nodes unchanged')
+
+  const origAuth = {
+    key: b4a.alloc(32),
+    discoveryKey: b4a.alloc(32),
+    manifest: null,
+    keyPair: null,
+    encryptionKey: null
+  }
+  t.not(await getAuth(core), origAuth, 'sanity check (core itself got updated)')
+  t.alike(await getAuth(snap), origAuth, 'auth unchanged')
+
+  t.not(await getHead(core), null, 'sanity check (core itself got updated)')
+  t.alike(await getHead(snap), null, 'head unchanged')
+
+  t.not(await getDependency(core), null, 'sanity check (core itself got updated)')
+  t.alike(await getDependency(snap), null, 'dependency unchanged')
+
+  t.not(await getHints(core), null, 'sanity check (core itself got updated)')
+  t.alike(await getHints(snap), null, 'hints unchanged')
+
+  t.not(await getUserData(core, 'key'), null, 'sanity check (core itself got updated)')
+  t.alike(await getUserData(snap, 'key'), null, 'userdata unchanged')
+
+  t.not(await getBitfieldPages(core, 2), [null, null], 'sanity check (core itself got updated)')
+  t.alike(await getBitfieldPages(snap, 2), [null, null], 'bitfield pages unchanged')
+})