Use typed json

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lekko/react-sdk",
-  "version": "0.7.2-beta-1",
+  "version": "0.7.2-beta-2",
   "main": "dist/index.cjs",
   "module": "dist/index.mjs",
   "types": "dist/index.d.ts",
@@ -14,6 +14,8 @@
     "@lekko/js-sdk": "^0.1.0-beta-5",
     "@tanstack/react-query": "^5.8.1",
     "dotenv": "^16.3.1",
+    "fp-ts": "^2.16.2",
+    "io-ts": "^2.2.21",
     "lz-string": "^1.5.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0"

src/hooks/useLekkoConfig.ts

@@ -17,6 +17,7 @@ import { upsertHistoryItem } from "../utils/overrides"
 import { LekkoSettingsContext } from "../providers/lekkoSettingsProvider"
 import { getCombinedContext } from "../utils/context"
 import { type ClientContext } from "@lekko/js-sdk"
+import type * as t from "io-ts"
 
 export function useLekkoConfig<E extends EvaluationType>(
   config: LekkoConfig<E>,
@@ -140,3 +141,27 @@ export function useProtoConfig(
     options,
   )
 }
+
+export function useTypedJSONConfig<A>(
+  config: UntypedLekkoConfig,
+  type: t.Type<A>,
+  options?: ConfigOptions,
+) {
+  const result = useLekkoConfig(
+    { ...config, evaluationType: EvaluationType.JSON },
+    options,
+  )
+  const evaluation = type.decode(result)
+
+  if (evaluation._tag === "Left") {
+    const errorMessage = evaluation.left
+      .map((validationError) => validationError.message)
+      .join("\n")
+
+    const error = new Error(errorMessage)
+
+    throw error
+  }
+
+  return evaluation.right
+}

yarn.lock

@@ -872,6 +872,8 @@ __metadata:
     eslint-plugin-promise: ^6.0.0
     eslint-plugin-react: latest
     eslint-plugin-react-hooks: ^4.6.0
+    fp-ts: ^2.16.2
+    io-ts: ^2.2.21
     jest: ^29.7.0
     jest-environment-jsdom: ^29.7.0
     lz-string: ^1.5.0
@@ -3228,6 +3230,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"fp-ts@npm:^2.16.2":
+  version: 2.16.2
+  resolution: "fp-ts@npm:2.16.2"
+  checksum: 5c2e3f096ba4be5646bda38a43e3e8ca3bd7693fefb26e6c4d4c451efbc9a227f7f7cad562b087cb134d4e41f4ae615602f0b17890e9e40a9e83f2f8822da666
+  languageName: node
+  linkType: hard
+
 "fs-minipass@npm:^2.0.0":
   version: 2.1.0
   resolution: "fs-minipass@npm:2.1.0"
@@ -3694,6 +3703,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"io-ts@npm:^2.2.21":
+  version: 2.2.21
+  resolution: "io-ts@npm:2.2.21"
+  peerDependencies:
+    fp-ts: ^2.5.0
+  checksum: c6ae5237e313f7428c874fa5667b3656adaa5ec29f7f34194ad8ea8894b525c89322a5b74ca560e7cd66f8334b0b48cae6c4dc517c662de72da86110140646d4
+  languageName: node
+  linkType: hard
+
 "ip-address@npm:^9.0.5":
   version: 9.0.5
   resolution: "ip-address@npm:9.0.5"