feat: allow providing community or group URI as activity object

both for joining and leaving

.env.sample

@@ -13,3 +13,6 @@ GROUP_TO_JOIN=""
 
 ## comma-separated list of URIs of the groups from which the person can be removed if present (required)
 GROUPS_TO_LEAVE=""
+
+## community URI that is also accepted as Activity object (optional)
+COMMUNITY=""

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Allow providing community or group URI as activity object
+
 ## [0.2.1] - 2025-01-07
 
 ### Fixed

README.md

@@ -58,10 +58,6 @@ yarn test
 
 Tests are placed in [src/test/](./src/test/)
 
-## TODO
-
-TODO
-
 ## License
 
 MIT

src/app.ts

@@ -17,6 +17,7 @@ export interface AppConfig {
   readonly isBehindProxy?: boolean
   readonly groupToJoin: string
   readonly groupsToLeave: string[]
+  readonly community?: string
 }
 
 const createApp = async (config: AppConfig) => {

src/config/index.ts

@@ -23,6 +23,8 @@ if (!process.env.GROUP_TO_JOIN)
     'Please specify GROUP_TO_JOIN in environment variables.',
   )
 
+export const community = process.env.COMMUNITY || undefined
+
 export const groupToJoin = process.env.GROUP_TO_JOIN
 
 export const groupsToLeave = envToArray(process.env.GROUPS_TO_LEAVE)

src/controllers/inbox.ts

@@ -11,7 +11,7 @@ export const verifyRequest: Middleware<{
   const actor = ctx.request.body.actor.id
   const authenticatedUser = ctx.state.user
   const object = ctx.request.body.object.id
-  const { groupToJoin, groupsToLeave } = ctx.state.config
+  const { groupToJoin, groupsToLeave, community } = ctx.state.config
   const task: 'Join' | 'Leave' = ctx.request.body.type
 
   if (actor !== authenticatedUser)
@@ -22,17 +22,22 @@ export const verifyRequest: Middleware<{
 
   switch (task) {
     case 'Join': {
-      if (object !== groupToJoin)
+      const allowedObjects = [groupToJoin]
+      if (community) allowedObjects.push(community)
+
+      if (!allowedObjects.includes(object))
         throw new ValidationError(
-          `Object does not match expected group.\nExpected: ${groupToJoin}\nActual: ${object}`,
+          `Object does not match expected group or community.\nExpected: ${allowedObjects.join(',')}\nActual: ${object}`,
           [],
         )
       break
     }
     case 'Leave': {
-      if (!groupsToLeave.includes(object))
+      const allowedObjects = [...groupsToLeave]
+      if (community) allowedObjects.push(community)
+      if (!allowedObjects.includes(object))
         throw new ValidationError(
-          `Object does not match any of the expected groups.\nExpected: ${groupsToLeave.join(',')}\nActual: ${object}`,
+          `Object does not match any of the expected groups or community.\nExpected: ${allowedObjects.join(',')}\nActual: ${object}`,
           [],
         )
       break
@@ -67,7 +72,7 @@ const joinGroup: Middleware<{
   user: string
   config: AppConfig
 }> = async ctx => {
-  const group = ctx.request.body.object.id
+  const group = ctx.state.config.groupToJoin
 
   const authFetch = await getAuthenticatedFetch(ctx.state.config.webId)
   const response = await authFetch(group, {
@@ -93,23 +98,82 @@ const leaveGroup: Middleware<{
   user: string
   config: AppConfig
 }> = async ctx => {
-  const group = ctx.request.body.object.id
+  const groupsToLeave: string[] = []
 
-  const authFetch = await getAuthenticatedFetch(ctx.state.config.webId)
-  const response = await authFetch(group, {
-    headers: { 'content-type': 'text/n3' },
-    method: 'PATCH',
-    body: `_:remove a <${solid.InsertDeletePatch}>;
+  // if object is a community, try removing person from all configured groups
+  if (ctx.request.body.object.id === ctx.state.config.community)
+    groupsToLeave.push(...ctx.state.config.groupsToLeave)
+  // other remove person from the specified group only
+  else groupsToLeave.push(ctx.request.body.object.id)
+
+  // attempt all defined removals
+  const settledResults = await Promise.allSettled(
+    groupsToLeave.map(async (group: string) => {
+      const authFetch = await getAuthenticatedFetch(ctx.state.config.webId)
+      return await authFetch(group, {
+        headers: { 'content-type': 'text/n3' },
+        method: 'PATCH',
+        body: `_:remove a <${solid.InsertDeletePatch}>;
         <${solid.deletes}> { <${group}> <${vcard.hasMember}> <${ctx.state.user}> . }.
       `,
-  })
+      })
+    }),
+  )
 
-  if (!response.ok)
-    throw new HttpError(
-      `Removing person ${ctx.state.user} from group ${group} failed.`,
-      response,
-      response.status === 409 ? 409 : 500,
-    )
+  // process results
+  const results = settledResults.reduce<{
+    // successful removals
+    success: { group: string; response: Response }[]
+    // http error responses
+    httpError: { group: string; response: Response }[]
+    // thrown errors
+    error: { group: string; error: unknown }[]
+  }>(
+    (results, result, i) => {
+      const group = groupsToLeave[i]
+      // this shouldn't happen, but skip just in case
+      if (!group) return results
 
-  ctx.status = 200
+      if (result.status === 'rejected') {
+        results.error.push({ group, error: result.reason })
+      } else if (result.value.ok) {
+        results.success.push({ group, response: result.value })
+      } else results.httpError.push({ group, response: result.value })
+
+      return results
+    },
+    { success: [], httpError: [], error: [] },
+  )
+
+  ctx.body = {
+    successes: results.success.map(r => r.group),
+    conflicts: results.httpError
+      .filter(r => r.response.status === 409)
+      .map(r => r.group),
+    errors: [
+      ...results.httpError
+        .filter(r => r.response.status !== 409)
+        .map(r => r.group),
+      ...results.error.map(r => r.group),
+    ],
+  }
+
+  // if some requests succeeded, return success
+  if (results.success.length > 0) ctx.status = 200
+  // if there is some unexpected failure, return internal server error
+  else if (
+    results.error.length > 0 ||
+    results.httpError.some(result => result.response.status !== 409)
+  )
+    ctx.status = 500
+  // if all errors are 409 Conflict, return 409 Conflict
+  // this is typically a result of trying to remove missing triple(s)
+  // https://solidproject.org/TR/protocol#server-patch-n3-semantics-deletions-non-empty-all-triples
+  else if (
+    results.httpError.length > 0 &&
+    results.httpError.every(result => result.response.status === 409)
+  )
+    ctx.status = 409
+  // and nothing else should be left over
+  else throw new Error('Unexpected error: unexpected condition')
 }

src/index.ts

@@ -1,15 +1,17 @@
 /* eslint-disable no-console */
 import { createApp } from './app.js'
 import {
+  community,
   groupsToLeave,
   groupToJoin,
   isBehindProxy,
   port,
   webId,
 } from './config/index.js'
 
-createApp({ webId, isBehindProxy, groupToJoin, groupsToLeave }).then(app =>
-  app.listen(port, async () => {
-    console.log(`community inbox service is listening on port ${port}`)
-  }),
+createApp({ webId, isBehindProxy, groupToJoin, groupsToLeave, community }).then(
+  app =>
+    app.listen(port, async () => {
+      console.log(`community inbox service is listening on port ${port}`)
+    }),
 )

src/test/join.spec.ts

@@ -165,4 +165,32 @@ describe('Joining the community', () => {
     // check that a Location header is present
     expect(response.headers.get('location')).toBe(ctx.community.group)
   })
+
+  test<TestContext>('[community instead of group] 200 should add the actor to the predefined group', async ctx => {
+    const person = ctx.people[0]
+
+    // check that the person is not in the group
+    expect(await checkMembership(person.webId, ctx.community.group)).toBe(false)
+
+    // send request to the app
+    const response = await person.fetch(`${ctx.app.origin}/inbox`, {
+      method: 'POST',
+      headers: { 'content-type': 'application/ld+json' },
+      body: JSON.stringify({
+        '@context': 'https://www.w3.org/ns/activitystreams',
+        type: 'Join',
+        actor: { type: 'Person', id: person.webId },
+        object: { type: 'Group', id: ctx.community.community },
+      }),
+    })
+
+    // receive response 200
+    expect(response.status).toBe(200)
+
+    // check that the person is in the group now
+    expect(await checkMembership(person.webId, ctx.community.group)).toBe(true)
+
+    // check that a Location header is present
+    expect(response.headers.get('location')).toBe(ctx.community.group)
+  })
 })

src/test/leave.spec.ts

@@ -175,4 +175,29 @@ describe('Leaving the community', () => {
     // check that the person is not in the group
     expect(await checkMembership(person.webId, ctx.community.group)).toBe(false)
   })
+
+  test<TestContext>("[object is community] should remove the actor from all predefined community's groups", async ctx => {
+    const person = ctx.people[2]
+
+    // check that the person is in the group
+    expect(await checkMembership(person.webId, ctx.community.group)).toBe(true)
+
+    // send request to the app
+    const response = await person.fetch(`${ctx.app.origin}/inbox`, {
+      method: 'POST',
+      headers: { 'content-type': 'application/ld+json' },
+      body: JSON.stringify({
+        '@context': 'https://www.w3.org/ns/activitystreams',
+        type: 'Leave',
+        actor: { type: 'Person', id: person.webId },
+        object: { type: 'Group', id: ctx.community.community },
+      }),
+    })
+
+    // receive response 200
+    expect(response.status).toBe(200)
+
+    // check that the person is not in the group
+    expect(await checkMembership(person.webId, ctx.community.group)).toBe(false)
+  })
 })

src/test/setup.ts

@@ -105,6 +105,7 @@ beforeEach<TestContext>(async ctx => {
     webId: ctx.app.webId,
     groupToJoin: ctx.community.group,
     groupsToLeave: [ctx.community.group],
+    community: ctx.community.community,
   })
 
   server = await new Promise(resolve => {