@pdfme/pdf-lib/__tests__/core/embedders/JpegEmbedder.spec.ts

Create and modify PDF files with JavaScript

import fs from 'fs';
import {
  JpegEmbedder,
  PDFContext,
  PDFRawStream,
  PDFRef,
} from '../../../src/core';

const catUnicornJpg = fs.readFileSync('./assets/images/cat_riding_unicorn.jpg');
const minionsLaughing = fs.readFileSync('./assets/images/minions_laughing.jpg');
const cmykJpg = fs.readFileSync('./assets/images/cmyk_colorspace.jpg');

describe(`JpegEmbedder`, () => {
  it(`can be constructed with JpegEmbedder.for(...)`, async () => {
    const embedder = await JpegEmbedder.for(catUnicornJpg);
    expect(embedder).toBeInstanceOf(JpegEmbedder);
  });

  it(`can embed JPEG images into PDFContexts without a predefined ref`, async () => {
    const context = PDFContext.create();
    const embedder = await JpegEmbedder.for(catUnicornJpg);

    expect(context.enumerateIndirectObjects().length).toBe(0);
    const ref = await embedder.embedIntoContext(context);
    expect(context.enumerateIndirectObjects().length).toBe(1);
    expect(context.lookup(ref)).toBeInstanceOf(PDFRawStream);
  });

  it(`can embed JPEG images into PDFContexts with a predefined ref`, async () => {
    const context = PDFContext.create();
    const predefinedRef = PDFRef.of(9999);
    const embedder = await JpegEmbedder.for(catUnicornJpg);

    expect(context.enumerateIndirectObjects().length).toBe(0);
    const ref = await embedder.embedIntoContext(context, predefinedRef);
    expect(context.enumerateIndirectObjects().length).toBe(1);
    expect(context.lookup(predefinedRef)).toBeInstanceOf(PDFRawStream);
    expect(ref).toBe(predefinedRef);
  });

  it(`can extract properties of JPEG images (1)`, async () => {
    const embedder = await JpegEmbedder.for(catUnicornJpg);

    expect(embedder.bitsPerComponent).toBe(8);
    expect(embedder.height).toBe(1080);
    expect(embedder.width).toBe(1920);
    expect(embedder.colorSpace).toBe('DeviceRGB');
  });

  it(`can extract properties of JPEG images (2)`, async () => {
    const embedder = await JpegEmbedder.for(minionsLaughing);

    expect(embedder.bitsPerComponent).toBe(8);
    expect(embedder.height).toBe(354);
    expect(embedder.width).toBe(630);
    expect(embedder.colorSpace).toBe('DeviceRGB');
  });

  it(`can extract properties of JPEG images (3)`, async () => {
    const embedder = await JpegEmbedder.for(cmykJpg);

    expect(embedder.bitsPerComponent).toBe(8);
    expect(embedder.height).toBe(333);
    expect(embedder.width).toBe(500);
    expect(embedder.colorSpace).toBe('DeviceCMYK');
  });
});