[WIP pending PR in hyperbee] Add compat test with hyperbee watch and autobase

package.json

@@ -18,10 +18,10 @@
   "author": "H. Degroote",
   "license": "Apache-2.0",
   "devDependencies": {
-    "autobase-next": "~0.0.1",
+    "autobase-next": "~0.0.2",
     "brittle": "^3.1.1",
     "corestore": "^6.5.0",
-    "hyperbee": "^2.5.0",
+    "hyperbee": "github:holepunchto/hyperbee#watch-change-event-2",
     "random-access-memory": "^6.1.0",
     "standard": "^17.0.0"
   },

test/watcher-compat.js

@@ -0,0 +1,64 @@
+const test = require('brittle')
+const { streamToArray, setup, confirm } = require('./helpers')
+
+test('compat - watch works with autobase bees', async function (t) {
+  // bee.watch() works very well with this module, so we add a test
+  // that ensures it remains compatible.
+  // The main possible compat issue is autobase-next
+  const bases = await setup(t)
+  const [base1, base2] = bases
+
+  const bee = base1.view.bee // bee based on autobase linearised core
+
+  const partialWatcher = bee.watch()
+  const fullWatcher = bee.watch()
+  const initBee = bee.snapshot()
+
+  // Start consuming the watchers
+  const consumePartialWatcherProm = consumeWatcher(partialWatcher)
+  const consumeFullWatcherProm = consumeWatcher(fullWatcher)
+
+  // Add shared entry
+  await base1.append({ entry: ['1-1', '1-entry1'] })
+  await confirm(base1, base2)
+
+  await partialWatcher.destroy()
+  const partialDiffs = await consumePartialWatcherProm
+
+  // Init state
+  t.alike(initBee.version, partialDiffs[0].previous.version)
+  // Final state
+  const partialFinal = await streamToArray(partialDiffs[partialDiffs.length - 1].current.createReadStream())
+  t.alike(partialFinal.length, 1) // Sanity check
+  t.alike(partialFinal, await streamToArray(bee.createReadStream()))
+
+  await Promise.all([
+    base1.append({ entry: ['1-2', '1-entry2'] }),
+    base2.append({ entry: ['2-1', '2-entry1'] }),
+    base2.append({ entry: ['2-2', '2-entry2'] })
+  ])
+  await confirm(base1, base2)
+
+  await fullWatcher.destroy()
+  const fullDiffs = await consumeFullWatcherProm
+
+  // sanity check. Even though the exact amount is non-deterministic
+  // it should have been triggered at least a few times.
+  t.is(fullDiffs.length > 1, true)
+  t.alike(
+    await streamToArray(fullDiffs[0].previous.createReadStream()),
+    await streamToArray(initBee.createReadStream())
+  )
+  // Final state
+  const finalEntries = await streamToArray(fullDiffs[fullDiffs.length - 1].current.createReadStream())
+  t.is(finalEntries.length, 4) // Sanity check
+  t.alike(finalEntries, await streamToArray(bee.createReadStream()))
+})
+
+async function consumeWatcher (watcher) {
+  const entries = []
+  for await (const { current, previous } of watcher) {
+    entries.push({ previous, current })
+  }
+  return entries
+}