Add Support for [Nostr] Followers (#9870)

* add nostr followers with tests

* fix broken test

* fix http error handler

* rename route from nostr to nostr-band

* remove unnecessary test cases

* edit test expectation

* validate data schema ensuring exact one key

* remove unavailable named logo

* migrate examples to openApi

* Update services/nostr-band/nostr-band-followers.tester.js

* remove unused import

---------

Co-authored-by: chris48s <chris48s@users.noreply.github.com>
Co-authored-by: chris48s <git@chris-shaw.dev>

services/nostr-band/nostr-band-followers.service.js

+import Joi from 'joi'
+import { metric } from '../text-formatters.js'
+import { BaseJsonService, pathParams } from '../index.js'
+
+const npubSchema = Joi.object({
+  followers_pubkey_count: Joi.number().required(),
+}).required()
+
+const mainSchema = Joi.object({
+  stats: Joi.object()
+    .pattern(Joi.string(), npubSchema)
+    .min(1)
+    .max(1)
+    .required(),
+}).required()
+
+export default class NostrBandFollowers extends BaseJsonService {
+  static category = 'social'
+
+  static route = {
+    base: 'nostr-band/followers',
+    pattern: ':npub',
+  }
+
+  static openApi = {
+    '/nostr-band/followers/{npub}': {
+      get: {
+        summary: 'Nostr.band Followers',
+        description:
+          'Returns the number of followers for a Nostr pubkey using the Nostr.band API.',
+        parameters: pathParams({
+          name: 'npub',
+          description: 'Nostr pubkey in (npub1...) format or hex.',
+          example:
+            'npub18c556t7n8xa3df2q82rwxejfglw5przds7sqvefylzjh8tjne28qld0we7',
+        }),
+      },
+    },
+  }
+
+  static defaultBadgeData = { label: 'followers' }
+
+  static render({ followers }) {
+    return {
+      message: metric(followers),
+      style: 'social',
+    }
+  }
+
+  async fetch({ npub }) {
+    const data = await this._requestJson({
+      url: `https://api.nostr.band/v0/stats/profile/${npub}`,
+      schema: mainSchema,
+      httpErrors: {
+        400: 'invalid pubkey',
+      },
+    })
+    const stats = data.stats
+    const firstKey = Object.keys(stats)[0]
+    return stats[firstKey].followers_pubkey_count
+  }
+
+  async handle({ npub }) {
+    const followers = await this.fetch({ npub })
+    return this.constructor.render({ followers })
+  }
+}

services/nostr-band/nostr-band-followers.tester.js

+import { isMetric } from '../test-validators.js'
+import { createServiceTester } from '../tester.js'
+export const t = await createServiceTester()
+
+t.create('fetch: valid npub')
+  .get('/npub18c556t7n8xa3df2q82rwxejfglw5przds7sqvefylzjh8tjne28qld0we7.json')
+  .expectBadge({
+    label: 'followers',
+    message: isMetric,
+  })
+
+t.create('fetch: invalid npub').get('/invalidnpub.json').expectBadge({
+  label: 'followers',
+  message: 'invalid pubkey',
+})