add logic to find newest service

.changeset/early-olives-explode.md

@@ -0,0 +1,5 @@
+---
+"@onflow/fcl": patch
+---
+
+Fix version normalization of services in FCL

packages/fcl/src/current-user/build-user.js

@@ -4,6 +4,7 @@ import {fetchServices} from "./fetch-services"
 import {mergeServices} from "./merge-services"
 import {USER_PRAGMA} from "../normalizers/service/__vsn"
 import {normalizeService} from "../normalizers/service/service"
+import {serviceOfType} from "./service-of-type"
 
 function deriveCompositeId(authn) {
   return rlp
@@ -20,10 +21,6 @@ function normalizeData(data) {
   return data
 }
 
-function findService(type, services) {
-  return services.find(d => d.type === type)
-}
-
 export async function buildUser(data) {
   data = normalizeData(data)
 
@@ -34,7 +31,7 @@ export async function buildUser(data) {
     .map(service => normalizeService(service, data))
     .filter(Boolean)
 
-  const authn = findService("authn", services)
+  const authn = serviceOfType(services, "authn")
 
   return {
     ...USER_PRAGMA,

packages/fcl/src/current-user/service-of-type.js

@@ -1,3 +1,30 @@
+import {invariant} from "@onflow/util-invariant"
+
+function compareVersions(a, b) {
+  function helper(a, b) {
+    if (a.length === 0) return 0
+    if (a[0] > b[0]) return true
+    if (a[0] < b[0]) return false
+    return helper(a.slice(1), b.slice(1))
+  }
+  const aVsn = a.split(".")
+  const bVsn = b.split(".")
+
+  invariant(aVsn.length === 3, "Invalid version: " + a)
+  invariant(bVsn.length === 3, "Invalid version: " + b)
+
+  return helper(a.split("."), b.split("."))
+}
+
 export function serviceOfType(services = [], type) {
-  return services.find(service => service.type === type)
+  // Find the greatest version of the service type
+  return services.reduce(
+    (service, mostRecent) =>
+      !mostRecent ||
+      (service.type === type &&
+        compareVersions(service.f_vsn, mostRecent.f_vsn))
+        ? service
+        : mostRecent,
+    null
+  )
 }