feat: add endpoint for maps plugin to get info about custom map

src/fastify-plugins/maps.js

@@ -1,9 +1,13 @@
+import fs from 'node:fs/promises'
+import path from 'node:path'
 import { fetch } from 'undici'
 import { Server as SMPServerPlugin } from 'styled-map-package'
 
 import { noop } from '../utils.js'
+import { NotFoundError, ENOENTError } from './utils.js'
 
 /** @import { FastifyPluginAsync } from 'fastify' */
+/** @import { Stats } from 'node:fs' */
 
 export const CUSTOM_MAP_PREFIX = 'custom'
 export const FALLBACK_MAP_PREFIX = 'fallback'
@@ -19,9 +23,62 @@ export const FALLBACK_MAP_PREFIX = 'fallback'
 /** @type {FastifyPluginAsync<MapsPluginOpts>} */
 export async function plugin(fastify, opts) {
   if (opts.customMapPath) {
+    const { customMapPath } = opts
+
+    fastify.get(`/${CUSTOM_MAP_PREFIX}/info`, async () => {
+      const baseUrl = new URL(fastify.prefix, fastify.listeningOrigin)
+
+      if (!baseUrl.href.endsWith('/')) {
+        baseUrl.href += '/'
+      }
+
+      const customStyleJsonUrl = new URL(
+        `${CUSTOM_MAP_PREFIX}/style.json`,
+        baseUrl
+      )
+      const response = await fetch(customStyleJsonUrl)
+
+      if (response.status === 404) {
+        throw new NotFoundError(customStyleJsonUrl.href)
+      }
+
+      if (!response.ok) {
+        throw new Error(`Failed to get style from ${customStyleJsonUrl.href}`)
+      }
+
+      /** @type {Stats | undefined} */
+      let stats
+
+      try {
+        stats = await fs.stat(customMapPath)
+      } catch (err) {
+        if (err instanceof Error && 'code' in err && err.code === 'ENOENT') {
+          throw new ENOENTError(customMapPath)
+        }
+
+        throw err
+      }
+
+      const style = await response.json()
+
+      const styleJsonName =
+        typeof style === 'object' &&
+        style &&
+        'name' in style &&
+        typeof style.name === 'string'
+          ? style.name
+          : undefined
+
+      return {
+        created: stats.ctime,
+        size: stats.size,
+        name: styleJsonName || path.parse(customMapPath).name,
+      }
+    })
+
     fastify.register(SMPServerPlugin, {
       prefix: CUSTOM_MAP_PREFIX,
-      filepath: opts.customMapPath,
+      filepath: customMapPath,
     })
   }
 

src/fastify-plugins/utils.js

@@ -7,6 +7,12 @@ export const NotFoundError = createError(
   404
 )
 
+export const ENOENTError = createError(
+  'FST_ENOENT',
+  "ENOENT: no such file or directory '%s'",
+  404
+)
+
 /**
  * @param {import('node:http').Server} server
  * @param {{ timeout?: number }} [options]

test/fastify-plugins/maps.js

@@ -1,4 +1,6 @@
 import assert from 'node:assert/strict'
+import fs from 'node:fs/promises'
+import path from 'node:path'
 import test from 'node:test'
 import Fastify from 'fastify'
 import { Reader } from 'styled-map-package'
@@ -223,6 +225,106 @@ test('/style.json resolves style.json of fallback map when custom and online are
   )
 })
 
+test('custom map info endpoint not available when custom map path not provided', async (t) => {
+  const server = setup(t)
+
+  server.register(MapServerPlugin, {
+    defaultOnlineStyleUrl: DEFAULT_ONLINE_STYLE_URL,
+    fallbackMapPath: DEFAULT_FALLBACK_MAP_FILE_PATH,
+  })
+
+  const address = await server.listen()
+
+  mockAgent.enableNetConnect(new URL(address).host)
+
+  const response = await server.inject({
+    method: 'GET',
+    url: `/${CUSTOM_MAP_PREFIX}/info`,
+  })
+
+  assert.equal(response.statusCode, 404)
+})
+
+test('custom map info endpoint returns not found error when custom map does not exist', async (t) => {
+  const server = setup(t)
+
+  const nonExistentFile =
+    path.parse(SAMPLE_SMP_FIXTURE_PATH).dir + '/does/not/exist.smp'
+
+  server.register(MapServerPlugin, {
+    customMapPath: nonExistentFile,
+    defaultOnlineStyleUrl: DEFAULT_ONLINE_STYLE_URL,
+    fallbackMapPath: DEFAULT_FALLBACK_MAP_FILE_PATH,
+  })
+
+  const address = await server.listen()
+
+  mockAgent.enableNetConnect(new URL(address).host)
+
+  const response = await server.inject({
+    method: 'GET',
+    url: `/${CUSTOM_MAP_PREFIX}/info`,
+  })
+
+  assert.equal(response.statusCode, 404)
+  assert.match(response.json().error, /Not Found/)
+})
+
+test('custom map info endpoint returns server error when custom map is invalid', async (t) => {
+  const server = setup(t)
+
+  const invalidFile = new URL(import.meta.url).pathname
+
+  server.register(MapServerPlugin, {
+    customMapPath: invalidFile,
+    defaultOnlineStyleUrl: DEFAULT_ONLINE_STYLE_URL,
+    fallbackMapPath: DEFAULT_FALLBACK_MAP_FILE_PATH,
+  })
+
+  const address = await server.listen()
+
+  mockAgent.enableNetConnect(new URL(address).host)
+
+  const response = await server.inject({
+    method: 'GET',
+    url: `/${CUSTOM_MAP_PREFIX}/info`,
+  })
+
+  assert.equal(response.statusCode, 500)
+  assert.match(response.json().error, /Internal Server Error/)
+})
+
+test('custom map info endpoint returns expected info when valid custom map is available', async (t) => {
+  const server = setup(t)
+
+  const smpStats = await fs.stat(SAMPLE_SMP_FIXTURE_PATH)
+
+  server.register(MapServerPlugin, {
+    customMapPath: SAMPLE_SMP_FIXTURE_PATH,
+    defaultOnlineStyleUrl: DEFAULT_ONLINE_STYLE_URL,
+    fallbackMapPath: DEFAULT_FALLBACK_MAP_FILE_PATH,
+  })
+
+  const address = await server.listen()
+
+  mockAgent.enableNetConnect(new URL(address).host)
+
+  const response = await server.inject({
+    method: 'GET',
+    url: `/${CUSTOM_MAP_PREFIX}/info`,
+  })
+
+  assert.equal(response.statusCode, 200)
+
+  const info = response.json()
+
+  assert.deepEqual(info, {
+    created: smpStats.ctime.toISOString(),
+    size: smpStats.size,
+    name: 'MapLibre',
+  })
+})
+
 /**
  * @param {import('node:test').TestContext} t
  */