f65db20c6d
Currently, template expressions and statements have their location recorded relative to the HTML element they are in, with no handle to absolute location in a source file except for a line/column location. However, the line/column location is also not entirely accurate, as it points an entire semantic expression, and not necessarily the start of an expression recorded by the expression parser. To support record of the source code expressions originate from, add a new `sourceSpan` field to `ASTWithSource` that records the absolute byte offset of an expression within a source code. Implement part 2 of [refactoring template parsing for stability](https://hackmd.io/@X3ECPVy-RCuVfba-pnvIpw/BkDUxaW84/%2FMA1oxh6jRXqSmZBcLfYdyw?type=book). PR Close #31391
Tests in this directory are excluded from running in the browser and only run in node.