try {
        let traceObj = JSON.parse(reader.result);
        if (Array.isArray(traceObj) && traceObj.every(obj => 'resourceSpans' in obj)) {
          const mergedResourceSpans = traceObj.reduce((acc, obj) => {
            acc.push(...obj.resourceSpans);
            return acc;
          }, []);

          traceObj = { resourceSpans: mergedResourceSpans };
        }
        if ('resourceSpans' in traceObj) {
          JaegerAPI.transformOTLP(traceObj)
            .then((result: string) => {
              resolve(result);
            })
            .catch(() => {
              reject(new Error(`Error converting traces to OTLP`));
            });
        }
      } catch (error: unknown) {
        reject(new Error(`Error parsing JSON: ${(error as Error).message}`));
      }
    };

  it('loads JSON data with single resourceSpans array successfully', async () => {
    const obj = { resourceSpans: [{ id: 1 }, { id: 2 }, { id: 3 }] };
    const file = new File([JSON.stringify(obj)], 'singleResourceSpans.json');
    const result = await readJsonFile({ file });
    expect(result).toEqual(JSON.stringify(obj));
  });

  it('loads JSON data with multiple resourceSpans arrays successfully', async () => {
    const obj1 = { resourceSpans: [{ id: 1 }, { id: 2 }] };
    const obj2 = { resourceSpans: [{ id: 3 }, { id: 4 }] };
    const file = new File([JSON.stringify([obj1, obj2])], 'multipleResourceSpans.json');
    const expectedResult = { resourceSpans: [...obj1.resourceSpans, ...obj2.resourceSpans] };
    const result = await readJsonFile({ file });
    expect(result).toEqual(JSON.stringify(expectedResult));
  });