Testing - Can't resolve all parameters for (ClassName)

Question

Context

I created an ApiService class to be able to handle our custom API queries, while using our own serializer + other features.

ApiSer

Answer 1

Using Jest?

In case anyone gets here AND you're using Jest to test your Angular app (hopefully we're a growing minority), you will run into this error if you are not emitting decorators. You'll need to update your tsconfig.spec.json file so it looks like:

{
  "extends": "../../tsconfig.json",
  "compilerOptions": {
    "emitDecoratorMetadata": true,
    "outDir": "../../out-tsc/spec",
    "types": [
      "jest",
      "node"
    ]
  },
  "files": [
  ],
  "include": [
    "**/*.spec.ts",
    "**/*.d.ts"
  ]
}