feat: interface pubsub (#60)

* feat: interface pubsub

* chore: pubsub router tests

* chore: move pubsub abstractions from gossipsub

* chore: address review

* chore: revamp docs

* chore: add emit self tests to interface

* chore: refactor base tests

* chore: publish should only accept one topic per api call

* chore: normalize msg before emit

* chore: do not reset inbound stream

* chore: apply suggestions from code review

Co-authored-by: Jacob Heun <jacobheun@gmail.com>

* chore: address review

* fix: remove subscribe handler

* chore: remove bits from create peerId

Co-authored-by: Jacob Heun <jacobheun@gmail.com>

* chore: remove delay from topic validators tests

* chore: add event emitter information

* fix: topic validator docs

Co-authored-by: Jacob Heun <jacobheun@gmail.com>

test/pubsub/instance.spec.js

@@ -0,0 +1,54 @@
+/* eslint-env mocha */
+'use strict'
+
+const { expect } = require('aegir/utils/chai')
+
+const PubsubBaseImpl = require('../../src/pubsub')
+const {
+  createPeerId,
+  mockRegistrar
+} = require('./utils')
+
+describe('pubsub instance', () => {
+  let peerId
+
+  before(async () => {
+    peerId = await createPeerId()
+  })
+
+  it('should throw if no debugName is provided', () => {
+    expect(() => {
+      new PubsubBaseImpl() // eslint-disable-line no-new
+    }).to.throw()
+  })
+
+  it('should throw if no multicodec is provided', () => {
+    expect(() => {
+      new PubsubBaseImpl({ // eslint-disable-line no-new
+        debugName: 'pubsub'
+      })
+    }).to.throw()
+  })
+
+  it('should throw if no libp2p is provided', () => {
+    expect(() => {
+      new PubsubBaseImpl({ // eslint-disable-line no-new
+        debugName: 'pubsub',
+        multicodecs: '/pubsub/1.0.0'
+      })
+    }).to.throw()
+  })
+
+  it('should accept valid parameters', () => {
+    expect(() => {
+      new PubsubBaseImpl({ // eslint-disable-line no-new
+        debugName: 'pubsub',
+        multicodecs: '/pubsub/1.0.0',
+        libp2p: {
+          peerId: peerId,
+          registrar: mockRegistrar
+        }
+      })
+    }).not.to.throw()
+  })
+})