betagouv/service-national-universel

import { getHeaders, readCSVBuffer } from "./fileService";
import { ERRORS } from "snu-lib";

describe("readCSVBuffer", () => {
  it("should parse well-formed CSV data with headers into an array of objects", async () => {
    const csvBuffer = Buffer.from("classe,cohort\n1-cl,1-co\n2-cl,2-co");
    const expectedResult = [
      { classe: "1-cl", cohort: "1-co" },
      { classe: "2-cl", cohort: "2-co" },
    ];

    const result = await readCSVBuffer(csvBuffer, true);
    expect(result).toEqual(expectedResult);
  });

  it("should parse well-formed CSV data without headers into an array of objects", async () => {
    const csvBuffer = Buffer.from("1-cl,1-co\n2-cl,2-co");
    const expectedResult = [
      ["1-cl", "1-co"],
      ["2-cl", "2-co"],
    ];

    const result = await readCSVBuffer(csvBuffer, false);
    expect(result).toEqual(expectedResult);
  });
  it("should reject on parsing failures", async () => {
    const badCsvBuffer = Buffer.from("header\nJohn,Twenty,55");
    const result = readCSVBuffer(badCsvBuffer, true);
    await expect(result).rejects.toThrow(ERRORS.CANNOT_PARSE_CSV);
  });
});

describe("getHeaders", () => {
  it("should return an array of unique headers from an array of objects", () => {
    const data = [
      { name: "John", age: 30, city: "New York" },
      { name: "Jane", age: 28, city: "London" },
      { name: "Bob", age: 35, city: "Paris" },
    ];
    const expectedResult = ["name", "age", "city"];

    const result = getHeaders(data);
    expect(result).toEqual(expectedResult);
  });

  it("should return an empty array if the input array is empty", () => {
    const data: any[] = [];
    const expectedResult: string[] = [];

    const result = getHeaders(data);
    expect(result).toEqual(expectedResult);
  });

  it("should return an array with a single header if all objects have the same header", () => {
    const data = [{ name: "John" }, { name: "Jane" }, { name: "Bob" }];
    const expectedResult = ["name"];

    const result = getHeaders(data);
    expect(result).toEqual(expectedResult);
  });

  it("should return an array with unique headers even if some objects have missing headers", () => {
    const data = [{ name: "John", age: 30 }, { name: "Jane" }, { name: "Bob", city: "Paris" }];
    const expectedResult = ["name", "age", "city"];

    const result = getHeaders(data);
    expect(result).toEqual(expectedResult);
  });
});