test: set up example with ts-transformer-keys

Author: ahnpnl

examples/package-lock.json

@@ -0,0 +1,14 @@
+import type { TsCompilerInstance } from 'ts-jest'
+import keysTransformer from 'ts-transformer-keys/transformer'
+import type { TransformationContext } from 'typescript'
+
+export const version = 1
+export const name = 'my-key-transformer'
+
+export function factory(compilerInstance: TsCompilerInstance) {
+  return (ctx: TransformationContext) => {
+    // @ts-expect-error testing purpose
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    return keysTransformer(compilerInstance.program!)(ctx)
+  }
+}

examples/react-app/hello-transformer.ts

@@ -3,6 +3,9 @@ import { createDefaultPreset } from 'ts-jest'
 
 const defaultPreset = createDefaultPreset({
   tsconfig: 'tsconfig.spec.json',
+  astTransformers: {
+    before: ['hello-transformer.ts'],
+  },
 })
 
 export default {

examples/react-app/jest.config.ts

@@ -29,6 +29,7 @@
     "jest": "^29.7.0",
     "jest-environment-jsdom": "^29.7.0",
     "ts-jest": "^29.4.0",
+    "ts-transformer-keys": "^0.4.4",
     "typescript": "~5.8.3",
     "vite": "^6.3.5"
   }