Jinja2Templates assertion error in starlette version >= 0.28

[mkaminsky]

Problem description

• Upgrading to FastAPI 0.108.0, allowed for a starlette upgrade to 0.32.0.post1 (previously I was on 0.27.0).
• Starlette version 0.28 includes this PR, which changes the way that Jinja2Templates() works.
• The code in Jinja2Templates.__init__() now has an assert directory or env
• titiler, though, passes in directory="" which python evaluates to False, which triggers the assert

  ...
  File "./main.py", line 9, in <module>
    from titiler.core.errors import DEFAULT_STATUS_CODES, add_exception_handlers
  File "..../lib/python3.11/site-packages/titiler/core/__init__.py", line 5, in <module>
    from . import dependencies, errors, factory, routing  # noqa
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ..../lib/python3.11/site-packages/titiler/core/factory.py", line 73, in <module>
    DEFAULT_TEMPLATES = Jinja2Templates(
                        ^^^^^^^^^^^^^^^^
  File "..../lib/python3.11/site-packages/starlette/templating.py", line 103, in __init__
    assert directory or env, "either 'directory' or 'env' arguments must be passed"
AssertionError: either 'directory' or 'env' arguments must be passed

Expected Output

No assertion error.

Environment Information

Ubuntu 22.04, python3.11

[tdrivas]

Hello everyone,

I face the same problem both in Windows 10 and Ubuntu 20 using Python 3.10

Possible solution?

Thanks in advance!

[mrgeorge]

I've experienced the same issue. Requiring starlette < 0.28 in my pip env resolves it until @jasongi 's fix in #744 is released.

[vincentsarago]

thanks everyone 🙏

I've push 2 different releases with fixes:

• 0.15.7: limit fastapi version to <0.107
• 0.16.0: limit fastapi version to >=0.107.0 + change in the code to adapt with new starlette version