Allow adding people back into a group

index.js

@@ -132,16 +132,12 @@ function init (ssb, config) {
           ...m.value.content.recps.filter(isFeed)
         ])
 
-        const record = keystore.group.get(groupId)
-        // if we haven't been in the group since before, register the group
-        if (record == null) {
-          return keystore.group.add(groupId, { key: groupKey, root }, (err) => {
-            if (err) return cb(err)
-            processAuthors(groupId, authors, m.value.author, cb)
-          })
-        } else {
+        // TODO: only add if we're one of the people being added by this msg
+        // TODO: i think getting re-added might not work atm, since the keyring might only mark you un-excluded if you add a *new* key, but we're just adding the same one. so prob need to patch keyring
+        return keystore.group.add(groupId, { key: groupKey, root }, (err) => {
+          if (err) return cb(err)
           processAuthors(groupId, authors, m.value.author, cb)
-        }
+        })
       })
     }),
     pull.drain(() => {}, (err) => {

method/group.js

@@ -129,7 +129,6 @@ module.exports = function GroupMethods (ssb, keystore, state) {
         ),
         pull.map(msg => msg.value.content.recps.slice(1)),
         pull.flatten(),
-        pull.unique(),
         pull.collect((err, addedMembers) => {
           if (err) return cb(err)
 
@@ -151,13 +150,34 @@ module.exports = function GroupMethods (ssb, keystore, state) {
             ),
             pull.map(msg => msg.value.content.excludes),
             pull.flatten(),
-            pull.unique(),
             pull.collect((err, excludedMembers) => {
               if (err) return cb(err)
 
-              // NOTE: this currently prevents people who've been removed from being re-added
-              // https://github.com/ssbc/ssb-tribes/issues/79
-              const members = addedMembers.filter(addedMember => !excludedMembers.includes(addedMember))
+              // calculate if the person has been added more times than they've been removed
+              // this is kind of basic but works. although lol people can add themselves back
+              //a fancier version would check the members tangle and maybe the author of the additions/exclusions
+              const numAdded = {}
+
+              addedMembers.forEach(addedMember => {
+                if (numAdded[addedMember] === undefined) {
+                  numAdded[addedMember] = 0
+                }
+                numAdded[addedMember]++
+              })
+
+              excludedMembers.forEach(excludedMember => {
+                if (numAdded[excludedMember] !== undefined) {
+                  numAdded[excludedMember]--
+                }
+              })
+
+              Object.keys(numAdded).forEach(member => {
+                if (numAdded[member] < 1) {
+                  delete numAdded[member]
+                }
+              })
+
+              const members = Object.keys(numAdded)
 
               return cb(null, members)
             })

test/api/exclude-members.test.js

@@ -3,8 +3,8 @@ const { promisify: p } = require('util')
 const { Server, replicate, FeedId } = require('../helpers')
 
 test('tribes.excludeMembers', async t => {
-  const kaitiaki = Server()
-  const newPerson = Server()
+  const kaitiaki = Server({ name: 'kaitiaki' })
+  const newPerson = Server({ name: 'newPerson' })
 
   const name = id => {
     if (id === kaitiaki.id) return 'kaitiaki '
@@ -55,6 +55,18 @@ test('tribes.excludeMembers', async t => {
 
     const excludedList = await p(newPerson.tribes.list)()
     t.deepEqual(excludedList, [], "new person can't list any groups anymore")
+
+    await p(kaitiaki.tribes.invite)(
+      groupId, [newPerson.id], {}
+    )
+
+    const reAddedAuthors = await p(kaitiaki.tribes.listAuthors)(groupId)
+    t.deepEqual(reAddedAuthors.sort(), [kaitiaki.id, newPerson.id].sort(), 're-added person is listed as a member')
+
+    await p(replicate)({ from: kaitiaki, to: newPerson, live: false, name })
+
+    const newPersonBackInGroup = await p(newPerson.tribes.get)(groupId)
+    t.equal(newPersonBackInGroup.excluded, undefined, 'new person is not excluded anymore')
   } catch (err) {
     t.fail(err)
   }