src/vs/editor/common/config/editorOptions.ts/EditorFontSize/validate
class EditorFontSize:	public override validate(input: any): number {
		const r = EditorFloatOption.float(input, this.defaultValue);
		if (r === 0) {
			return EDITOR_FONT_DEFAULTS.fontSize;
		}
		return EditorFloatOption.clamp(r, 6, 100);
	}