Add trailing comma for single-element import-from groups

[charliermarsh]

Summary

Unlike other statements, Black always adds a trailing comma if an import-from statement breaks with a single import member. I believe this is for compatibility with isort -- see psf/black@09f5ee3, psf/black#127, or https://github.com/psf/black/blob/66648c528a95553c1f822ece394ac98784baee47/src/black/linegen.py#L1452 for the current version.

Test Plan

cargo test, notice that a big chunk of the compatibility suite is removed.

Before:

project	similarity index
cpython	0.75472
django	0.99804
transformers	0.99618
twine	0.99876
typeshed	0.74233
warehouse	0.99601
zulip	0.99727

After:

project	similarity index
cpython	0.75472
django	0.99804
transformers	0.99618
twine	0.99876
typeshed	0.74260
warehouse	0.99601
zulip	0.99727

[github-actions]

PR Check Results

Benchmark

Linux

group                                      main                                   pr
-----                                      ----                                   --
formatter/large/dataset.py                 1.00      4.5±0.04ms     9.0 MB/sec    1.02      4.6±0.04ms     8.8 MB/sec
formatter/numpy/ctypeslib.py               1.00    913.7±3.55µs    18.2 MB/sec    1.01    926.4±4.11µs    18.0 MB/sec
formatter/numpy/globals.py                 1.00     93.1±0.43µs    31.7 MB/sec    1.01     94.2±0.47µs    31.3 MB/sec
formatter/pydantic/types.py                1.00  1846.7±11.72µs    13.8 MB/sec    1.01  1870.1±32.57µs    13.6 MB/sec
linter/all-rules/large/dataset.py          1.00     12.2±0.04ms     3.3 MB/sec    1.00     12.2±0.03ms     3.3 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.00      3.3±0.01ms     5.1 MB/sec    1.00      3.3±0.02ms     5.1 MB/sec
linter/all-rules/numpy/globals.py          1.00    462.8±0.60µs     6.4 MB/sec    1.00    464.1±7.41µs     6.4 MB/sec
linter/all-rules/pydantic/types.py         1.00      6.3±0.02ms     4.0 MB/sec    1.00      6.3±0.03ms     4.0 MB/sec
linter/default-rules/large/dataset.py      1.00      6.5±0.02ms     6.3 MB/sec    1.01      6.5±0.07ms     6.3 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.00  1434.1±11.36µs    11.6 MB/sec    1.00  1427.1±21.51µs    11.7 MB/sec
linter/default-rules/numpy/globals.py      1.00    168.9±1.86µs    17.5 MB/sec    1.00    168.9±5.98µs    17.5 MB/sec
linter/default-rules/pydantic/types.py     1.00      2.9±0.01ms     8.7 MB/sec    1.00      2.9±0.01ms     8.8 MB/sec

Windows

group                                      main                                   pr
-----                                      ----                                   --
formatter/large/dataset.py                 1.01      4.2±0.10ms     9.7 MB/sec    1.00      4.2±0.08ms     9.8 MB/sec
formatter/numpy/ctypeslib.py               1.00   791.9±13.15µs    21.0 MB/sec    1.00   788.2±11.42µs    21.1 MB/sec
formatter/numpy/globals.py                 1.01     80.7±2.25µs    36.6 MB/sec    1.00     80.1±1.62µs    36.8 MB/sec
formatter/pydantic/types.py                1.00  1652.4±55.11µs    15.4 MB/sec    1.00  1645.8±28.71µs    15.5 MB/sec
linter/all-rules/large/dataset.py          1.00     12.7±0.10ms     3.2 MB/sec    1.01     12.8±0.19ms     3.2 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.00      3.5±0.02ms     4.7 MB/sec    1.01      3.6±0.03ms     4.7 MB/sec
linter/all-rules/numpy/globals.py          1.01    378.5±9.13µs     7.8 MB/sec    1.00    376.6±6.35µs     7.8 MB/sec
linter/all-rules/pydantic/types.py         1.02      6.7±0.20ms     3.8 MB/sec    1.00      6.6±0.06ms     3.9 MB/sec
linter/default-rules/large/dataset.py      1.00      7.0±0.06ms     5.8 MB/sec    1.00      7.0±0.05ms     5.8 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.01  1484.3±79.43µs    11.2 MB/sec    1.00  1465.1±20.57µs    11.4 MB/sec
linter/default-rules/numpy/globals.py      1.01    154.2±5.00µs    19.1 MB/sec    1.00    152.5±2.14µs    19.3 MB/sec
linter/default-rules/pydantic/types.py     1.01      3.2±0.04ms     8.0 MB/sec    1.00      3.1±0.06ms     8.1 MB/sec