tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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font-test-utils.js (2754B)

      1 'use strict';
      2 
      3 // Filters an array of FontData by font names. Used to reduce down
      4 // the size of test data.
      5 function filterFonts(fonts, filter) {
      6  const filteredFont = [];
      7  for (const font of fonts) {
      8    if (filter.includes(font.postscriptName)) {
      9      filteredFont.push(font);
     10    }
     11  }
     12  return filteredFont;
     13 }
     14 
     15 async function parseFontData(fontBlob) {
     16  // Parsed result to be returned.
     17  const fontInfo = {};
     18 
     19  try {
     20    // Parse the version info.
     21    fontInfo.versionTag = await getTag(fontBlob, 0);
     22    // Parse the table data.
     23    const numTables = await getUint16(fontBlob, 4);
     24    [fontInfo.tables, fontInfo.tableMeta] =
     25        await getTableData(fontBlob, numTables);
     26  } catch (error) {
     27    throw `Error parsing font table: ${error.message}`;
     28  }
     29 
     30  return fontInfo;
     31 }
     32 
     33 async function getTableData(fontBlob, numTables) {
     34  const dataMap = new Map();
     35  const metaMap = new Map();
     36  let blobOffset = 12;
     37 
     38  for (let i = 0; i < numTables; i++) {
     39    const tag = await getTag(fontBlob, blobOffset);
     40    const checksum = await getUint32(fontBlob, blobOffset + 4);
     41    const offset = await getUint32(fontBlob, blobOffset + 8);
     42    const size = await getUint32(fontBlob, blobOffset + 12);
     43    const tableBlob = fontBlob.slice(offset, offset + size);
     44    dataMap.set(tag, tableBlob);
     45    metaMap.set(tag, {checksum, offset, size});
     46    blobOffset += 16;
     47  }
     48 
     49  return [dataMap, metaMap];
     50 }
     51 
     52 async function getTag(blob, offset) {
     53  return (new TextDecoder)
     54      .decode(await blob.slice(offset, offset + 4).arrayBuffer());
     55 }
     56 
     57 async function getUint16(blob, offset) {
     58  const slice = blob.slice(offset, offset + 2);
     59  const buf = await slice.arrayBuffer();
     60  const dataView = new DataView(buf);
     61  return dataView.getUint16(0);
     62 }
     63 
     64 async function getUint32(blob, offset) {
     65  const slice = blob.slice(offset, offset + 4);
     66  const buf = await slice.arrayBuffer();
     67  const dataView = new DataView(buf);
     68  return dataView.getUint32(0);
     69 }
     70 
     71 function promiseDocumentReady() {
     72  return new Promise(resolve => {
     73    if (document.readyState === 'complete') {
     74      resolve();
     75    }
     76    window.addEventListener('load', () => {
     77      resolve();
     78    }, {once: true});
     79  });
     80 }
     81 
     82 function isPlatformSupported() {
     83  if (navigator.platform.indexOf('Mac') !== -1 ||
     84      navigator.platform.indexOf('Win') !== -1 ||
     85      navigator.platform.indexOf('Linux') !== -1) {
     86    return true;
     87  }
     88  return false;
     89 }
     90 
     91 function font_access_test(test_function, name, properties) {
     92  return promise_test(async (t) => {
     93    if (!isPlatformSupported()) {
     94      await promise_rejects_dom(t, 'NotSupportedError', self.queryLocalFonts());
     95      return;
     96    }
     97    await test_driver.set_permission({name: 'local-fonts'}, 'granted');
     98    await test_function(t, name, properties);
     99  });
    100 }