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.
12. The method of claim 1 , further comprising dividing the text content into the plurality of text parts such that the number of text parts is as small as possible without reducing the portion of the text content covered by the text parts.