import { assert, describe, it } from "vitest";
import dottedGet from "../../functions/dotted_get";

// ErrorDict: { [key: string]: string[] | ErrorDict }
// dottedGet(errors, fieldName) traverses the dict using dot-notation field names.

describe("dottedGet — flat keys", () => {
  it("returns the error array for a matching flat key", () => {
    const errors = { name: ["This field is required."] };
    assert.deepEqual(dottedGet(errors, "name"), ["This field is required."]);
  });

  it("returns undefined when the key is not present", () => {
    assert.isUndefined(dottedGet({ name: ["error"] }, "other"));
  });

  it("returns undefined when errors is undefined", () => {
    assert.isUndefined(dottedGet(undefined, "name"));
  });

  it("returns undefined when errors is null", () => {
    assert.isUndefined(dottedGet(null, "name"));
  });
});

describe("dottedGet — dot-notation keys", () => {
  it("reads nested errors one level deep", () => {
    const errors = { address: { street: ["Enter a street address."] } };
    assert.deepEqual(dottedGet(errors, "address.street"), [
      "Enter a street address.",
    ]);
  });

  it("reads nested errors two levels deep", () => {
    const errors = { a: { b: { c: ["Too short."] } } };
    assert.deepEqual(dottedGet(errors, "a.b.c"), ["Too short."]);
  });

  it("returns a nested ErrorDict when the path resolves to a sub-dict", () => {
    const errors = {
      address: { street: ["Required."], city: ["Required."] },
    };
    assert.deepEqual(dottedGet(errors, "address"), {
      street: ["Required."],
      city: ["Required."],
    });
  });

  it("returns undefined when an intermediate key is missing", () => {
    assert.isUndefined(dottedGet({}, "address.street"));
  });

  it("returns undefined when a mid-path value is not an object", () => {
    assert.isUndefined(
      dottedGet({ address: ["Invalid address."] }, "address.street"),
    );
  });

  it("returns undefined when errors is undefined and path has dots", () => {
    assert.isUndefined(dottedGet(undefined, "address.street"));
  });
});