--show-source code frames should respect Jupyter cells

[charliermarsh]

I have two cells, one containing two imports, and another containing a function definition.

When I run cargo run -p ruff_cli -- check Untitled.ipynb -n --watch --show-source, I get:

Untitled.ipynb:cell 1:2:8: F401 [*] `sys` imported but unused
  |
1 | import os
2 | import sys
  |        ^^^ F401
3 | def f(x):
4 |     y = x * x
  |
  = help: Remove unused import: `sys`

Untitled.ipynb:cell 2:2:5: F841 [*] Local variable `y` is assigned to but never used
  |
2 | import sys
3 | def f(x):
4 |     y = x * x
  |     ^ F841
5 |     print(x * x)
6 | f(2)
  |
  = help: Remove assignment to unused variable `y`

I think the code frames need to be reindexed. Notice that in the second error, the location is reported as cell 2:2:5, but in the code frame, the violation is on line 4.

Similarly, we should omit any contents from adjoining cells when displaying the code frame (in my opinion) -- so the second diagnostic shouldn't show the import sys.

[charliermarsh]

\cc @dhruvmanila - Wdyt?

[dhruvmanila]

Ah yes, this is true. I'll need to look into how source is being shown currently. Most likely the cell separation concept could be common for --show-source and --diff option.