Monaco editor 0.33.0 defineTheme fails with Cannot read properties of undefined (reading 'editor.foreground')

[cirosantilli]

Error:

    monaco.editor.defineTheme('vs-dark-ourbigbook', {
      base: 'vs-dark',
      inherit: true,
      rules: [
        { token: 'argumentDelim', foreground: 'FFFFFF', fontStyle: 'bold' },
        { token: 'argumentName', foreground: 'FFAAFF', fontStyle: 'bold'},
        { token: 'insaneHeader', foreground: 'FFFF00', fontStyle: 'bold' },
        { token: 'literalStart', foreground: 'FFFF00', fontStyle: 'bold' },
        { token: 'literalInside', foreground: 'FFFF88' },
        { token: 'macro', foreground: 'FF8800', fontStyle: 'bold' },
      ],
      // This option became mandatory after some update, even if empty, otherwise:
      // Cannot read properties of undefined (reading 'editor.foreground')
      colors: {},
    });
    const editor = monaco.editor.create(
      input_elem,
      {
        // https://stackoverflow.com/questions/47017753/monaco-editor-dynamically-resizable
        automaticLayout: true,
        folding: false,
        language: 'ourbigbook',
        minimap: {enabled: false},
        scrollBeyondLastLine: false,
        theme: 'vs-dark-ourbigbook',
        wordWrap: 'on',
        value: initial_content,
      }
    );

Fix: add a dummy colors: to it:

    monaco.editor.defineTheme('vs-dark-ourbigbook', {
      base: 'vs-dark',
      inherit: true,
      rules: [
        { token: 'argumentDelim', foreground: 'FFFFFF', fontStyle: 'bold' },
        { token: 'argumentName', foreground: 'FFAAFF', fontStyle: 'bold'},
        { token: 'insaneHeader', foreground: 'FFFF00', fontStyle: 'bold' },
        { token: 'literalStart', foreground: 'FFFF00', fontStyle: 'bold' },
        { token: 'literalInside', foreground: 'FFFF88' },
        { token: 'macro', foreground: 'FF8800', fontStyle: 'bold' },
      ],
      // This option became mandatory after some update, even if empty, otherwise:
      // Cannot read properties of undefined (reading 'editor.foreground')
      colors: {},
    });

No patience to minimize for SO right now, so Google please index this.

Happened at: https://github.com/************/ourbigbook/blob/c439d1b56817ea456e4171e92c6f031ee151c74c/web/package.json#L54 fixed at that commit.