1. A computer-implemented method for checking bidirectional text in text content, comprising: for each text part of a plurality of text parts in the text content: determining an intrinsic text direction of the text part, wherein the intrinsic text direction of the text part is determined to be: (i) left-to-right when the text part has a Unicode value indicating left-to-right, and (ii) right-to-left when the text part has a Unicode value indicating right-to-left; determining a declared text direction associated with the text part, wherein determining the declared text direction includes: applying a Unicode Bidirectional Algorithm to the text part, and noting a lowest explicit embedding level assigned by the Unicode Bidirectional Algorithm to any character of the text part and whether the Unicode Bidirectional Algorithm assigned a neutral override status to any of the characters with that lowest explicit embedding level, wherein the declared direction is left-to-right when that lowest explicit embedding level was even and had a neutral override status, and the declared direction is right-to-left when that lowest override status was odd and had a neutral override status, and otherwise declaring the declared as undefined; generating, with a computing device, a bidirectional text error based on a mismatch between the intrinsic text direction and the declared text direction; and reporting the bidirectional text error.