Steps to reproduce,
1. Create a pipeline with joiner
2. Rename a coloumn in the joiner to have `-`
3. Write it to bq sink
4. Clicking on validate returns no error
5. Run preview
After step 5 the pipeline fails with illegal character in schema exception. Have attached exception for reference.
The same pipeline runs fine if `-` in the alias is replaced with `_`
Columns names are validated for big query sink
This is correct behavior at runtime, as BigQuery doesn't support columns with the dash character '-' in them.
However, this should be caught during validation where we can highlight the problematic field and give a clear reason instead of failing at runtime.