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

Create and modify PDF files with JavaScript

import { FontNames } from '@pdf-lib/standard-fonts';
import {
  PDFContext,
  PDFDict,
  PDFHexString,
  PDFRef,
  StandardFontEmbedder,
} from '../../../src/index';

describe(`StandardFontEmbedder`, () => {
  it(`can be constructed with StandardFontEmbedder.for(...)`, () => {
    const embedder = StandardFontEmbedder.for(FontNames.Helvetica);
    expect(embedder).toBeInstanceOf(StandardFontEmbedder);
  });

  it(`exposes the font's name`, () => {
    const embedder = StandardFontEmbedder.for(FontNames.HelveticaOblique);
    expect(embedder.fontName).toBe('Helvetica-Oblique');
  });

  it(`can use a custom font name`, () => {
    const customName = 'Roboto 2';
    const embedder = StandardFontEmbedder.for(
      FontNames.HelveticaOblique,
      customName,
    );
    expect(embedder.customName).toBe(customName);
  });

  it(`can embed standard font dictionaries into PDFContexts without a predefined ref`, () => {
    const context = PDFContext.create();
    const embedder = StandardFontEmbedder.for(FontNames.Courier);

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

  it(`can embed standard font dictionaries into PDFContexts with a predefined ref`, () => {
    const context = PDFContext.create();
    const predefinedRef = PDFRef.of(9999);
    const embedder = StandardFontEmbedder.for(FontNames.Courier);

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

  it(`can encode text strings into PDFHexString objects`, () => {
    const text = 'Stuff and thingz!';
    const embedder = StandardFontEmbedder.for(FontNames.TimesRoman);
    expect(embedder.encodeText(text)).toBeInstanceOf(PDFHexString);
    expect(String(embedder.encodeText(text))).toBe(
      String(PDFHexString.of('537475666620616E64207468696E677A21')),
    );
  });

  it(`can measure the width of text strings at the given font size`, () => {
    const text = 'Stuff and thingz!';
    const embedder = StandardFontEmbedder.for(FontNames.HelveticaBold);
    expect(embedder.widthOfTextAtSize(text, 12)).toBe(94.656);
    expect(embedder.widthOfTextAtSize(text, 24)).toBe(189.312);
  });

  it(`can measure the height of the font at the given size`, () => {
    const embedder = StandardFontEmbedder.for(FontNames.HelveticaBold);
    expect(embedder.heightOfFontAtSize(12)).toBeCloseTo(11.1);
    expect(embedder.heightOfFontAtSize(24)).toBeCloseTo(22.2);
  });

  it(`can measure the size of the font at a given height`, () => {
    const embedder = StandardFontEmbedder.for(FontNames.HelveticaBold);
    expect(embedder.sizeOfFontAtHeight(12)).toBeCloseTo(12.972);
    expect(embedder.sizeOfFontAtHeight(24)).toBeCloseTo(25.945);
  });
});