1  const { TextEditor, TextBuffer } = require('atom');
  2  
  3  const MIN_SIZE_IN_KB = 0 * 1024;
  4  const MAX_SIZE_IN_KB = 10 * 1024;
  5  const SIZE_STEP_IN_KB = 1024;
  6  const LINE_TEXT = 'Lorem ipsum dolor sit amet\n';
  7  const TEXT = LINE_TEXT.repeat(
  8    Math.ceil((MAX_SIZE_IN_KB * 1024) / LINE_TEXT.length)
  9  );
 10  
 11  module.exports = async ({ test }) => {
 12    const data = [];
 13  
 14    document.body.appendChild(atom.workspace.getElement());
 15  
 16    atom.packages.loadPackages();
 17    await atom.packages.activate();
 18  
 19    for (let pane of atom.workspace.getPanes()) {
 20      pane.destroy();
 21    }
 22  
 23    for (
 24      let sizeInKB = MIN_SIZE_IN_KB;
 25      sizeInKB < MAX_SIZE_IN_KB;
 26      sizeInKB += SIZE_STEP_IN_KB
 27    ) {
 28      const text = TEXT.slice(0, sizeInKB * 1024);
 29      console.log(text.length / 1024);
 30  
 31      let t0 = window.performance.now();
 32      const buffer = new TextBuffer({ text });
 33      const editor = new TextEditor({
 34        buffer,
 35        autoHeight: false,
 36        largeFileMode: true
 37      });
 38      atom.grammars.autoAssignLanguageMode(buffer);
 39      atom.workspace.getActivePane().activateItem(editor);
 40      let t1 = window.performance.now();
 41  
 42      data.push({
 43        name: 'Opening a large file',
 44        x: sizeInKB,
 45        duration: t1 - t0
 46      });
 47  
 48      const tickDurations = [];
 49      for (let i = 0; i < 20; i++) {
 50        await timeout(50);
 51        t0 = window.performance.now();
 52        await timeout(0);
 53        t1 = window.performance.now();
 54        tickDurations[i] = t1 - t0;
 55      }
 56  
 57      data.push({
 58        name: 'Max time event loop was blocked after opening a large file',
 59        x: sizeInKB,
 60        duration: Math.max(...tickDurations)
 61      });
 62  
 63      t0 = window.performance.now();
 64      editor.setCursorScreenPosition(
 65        editor.element.screenPositionForPixelPosition({
 66          top: 100,
 67          left: 30
 68        })
 69      );
 70      t1 = window.performance.now();
 71  
 72      data.push({
 73        name: 'Clicking the editor after opening a large file',
 74        x: sizeInKB,
 75        duration: t1 - t0
 76      });
 77  
 78      t0 = window.performance.now();
 79      editor.element.setScrollTop(editor.element.getScrollTop() + 100);
 80      t1 = window.performance.now();
 81  
 82      data.push({
 83        name: 'Scrolling down after opening a large file',
 84        x: sizeInKB,
 85        duration: t1 - t0
 86      });
 87  
 88      editor.destroy();
 89      buffer.destroy();
 90      await timeout(10000);
 91    }
 92  
 93    atom.workspace.getElement().remove();
 94  
 95    return data;
 96  };
 97  
 98  function timeout(duration) {
 99    return new Promise(resolve => setTimeout(resolve, duration));
100  }