pdf-visual-compare/out/comparePdf.js

Visual regression testing library for PDFs in Js/Ts without binary and OS dependencies.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.comparePdf = comparePdf;
const node_fs_1 = require("node:fs");
const node_path_1 = require("node:path");
const pdf_to_png_converter_1 = require("pdf-to-png-converter");
const png_visual_compare_1 = require("png-visual-compare");
const const_js_1 = require("./const.js");
/**
 * Compares two PDF files or buffers and returns a boolean indicating whether they are similar.
 *
 * @param actualPdf - The file path or buffer of the actual PDF to compare.
 * @param expectedPdf - The file path or buffer of the expected PDF to compare against.
 * @param opts - Optional comparison options.
 * @returns A promise that resolves to a boolean indicating whether the PDFs are similar.
 * @throws Will throw an error if the compare threshold is less than 0.
 */
async function comparePdf(actualPdf, expectedPdf, opts = {}) {
    // Validate input file types
    validateInputFileType(actualPdf);
    validateInputFileType(expectedPdf);
    // Set default options
    const pdfToPngConvertOpts = { ...opts.pdfToPngConvertOptions };
    if (!pdfToPngConvertOpts.viewportScale) {
        pdfToPngConvertOpts.viewportScale = 2.0;
    }
    if (!pdfToPngConvertOpts.outputFileMaskFunc) {
        pdfToPngConvertOpts.outputFileMaskFunc = (pageNumber) => `comparePdf_${pageNumber}.png`;
    }
    const diffsOutputFolder = opts?.diffsOutputFolder ?? const_js_1.DEFAULT_DIFFS_FOLDER;
    const compareThreshold = opts?.compareThreshold ?? 0;
    const excludedAreas = opts?.excludedAreas ?? [];
    if (compareThreshold < 0) {
        throw Error('Compare Threshold cannot be less than 0.');
    }
    // Convert PDFs to PNGs
    let [actualPdfPngPages, expectedPdfPngPages] = await Promise.all([
        (0, pdf_to_png_converter_1.pdfToPng)(actualPdf, pdfToPngConvertOpts),
        (0, pdf_to_png_converter_1.pdfToPng)(expectedPdf, pdfToPngConvertOpts),
    ]);
    // Ensure actualPdfPngPages is always the longer array to avoid index out of bounds errors
    if (actualPdfPngPages.length < expectedPdfPngPages.length) {
        [actualPdfPngPages, expectedPdfPngPages] = [expectedPdfPngPages, actualPdfPngPages];
    }
    let documentCompareResult = true;
    actualPdfPngPages.forEach((pngPage, index) => {
        const comparePngOpts = {
            ...opts?.pdfToPngConvertOptions,
            ...excludedAreas[index],
            throwErrorOnInvalidInputData: false,
        };
        comparePngOpts.diffFilePath = (0, node_path_1.resolve)(diffsOutputFolder, `diff_${pngPage.name}`);
        const pngPageOutputToCompareWith = expectedPdfPngPages.find((p) => p.name === pngPage.name);
        const pageCompareResult = (0, png_visual_compare_1.comparePng)(pngPage.content, pngPageOutputToCompareWith?.content ?? '', comparePngOpts);
        if (pageCompareResult > compareThreshold) {
            documentCompareResult = false;
        }
    });
    return documentCompareResult;
}
/**
 * Validates the type of the input file. The input file can either be a Buffer or a string representing a file path.
 * If the input file is a Buffer, the function returns without any error.
 * If the input file is a string, the function checks if the file exists at the given path.
 * If the file does not exist, an error is thrown.
 * If the input file is neither a Buffer nor a string, an error is thrown.
 *
 * @param inputFile - The input file to validate. It can be a Buffer or a string representing a file path.
 * @throws {Error} If the input file is a string and the file does not exist.
 * @throws {Error} If the input file is neither a Buffer nor a string.
 */
function validateInputFileType(inputFile) {
    if (Buffer.isBuffer(inputFile)) {
        return;
    }
    if (typeof inputFile === 'string') {
        if ((0, node_fs_1.existsSync)(inputFile)) {
            return;
        }
        else {
            throw Error(`PDF file not found: ${inputFile}`);
        }
    }
    throw Error(`Unknown input file type.`);
}