Format if statements

[MichaReiser]

Summary

This PR implements the formatting of if statements. I haven't verified if it covers all edge cases because
that will be easier once we have better coverage (you can simply go througth the black differences), but I believe it covers most reasonable uses pretty well.

Test Plan

A few own unit tests and reviewed (as best as I can) the black differences

[MichaReiser]

Current dependencies on/for this PR:

• main
  • PR Add basic Constant formatting #4954
    • PR Trailing own line comments before func or class #4921
      • PR Simple lexer for formatter #4922
        • PR Format Function definitions #4951
          • PR Format if statements #4961 👈
            • PR Fix binary expression formatting with leading comments #4964
              • PR Track formatted comments #4979
              • PR perf(formatter): Skip bodies without comments #4978

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[github-actions]

PR Check Results

Ecosystem

✅ ecosystem check detected no changes.

Benchmark

Linux

group                                      main                                   pr
-----                                      ----                                   --
formatter/large/dataset.py                 1.00      6.8±0.01ms     6.0 MB/sec    1.01      6.9±0.01ms     5.9 MB/sec
formatter/numpy/ctypeslib.py               1.00   1382.1±3.95µs    12.0 MB/sec    1.01   1390.5±3.18µs    12.0 MB/sec
formatter/numpy/globals.py                 1.00    138.3±0.21µs    21.3 MB/sec    1.01    139.1±0.87µs    21.2 MB/sec
formatter/pydantic/types.py                1.00      2.8±0.01ms     9.2 MB/sec    1.01      2.8±0.01ms     9.1 MB/sec
linter/all-rules/large/dataset.py          1.02     15.1±0.06ms     2.7 MB/sec    1.00     14.8±0.02ms     2.7 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.01      3.6±0.00ms     4.6 MB/sec    1.00      3.6±0.00ms     4.6 MB/sec
linter/all-rules/numpy/globals.py          1.01    369.8±1.42µs     8.0 MB/sec    1.00    367.0±1.74µs     8.0 MB/sec
linter/all-rules/pydantic/types.py         1.01      6.3±0.01ms     4.1 MB/sec    1.00      6.2±0.01ms     4.1 MB/sec
linter/default-rules/large/dataset.py      1.03      7.5±0.01ms     5.4 MB/sec    1.00      7.3±0.02ms     5.6 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.02   1568.8±5.41µs    10.6 MB/sec    1.00   1531.1±3.97µs    10.9 MB/sec
linter/default-rules/numpy/globals.py      1.02    167.7±0.98µs    17.6 MB/sec    1.00    164.0±0.30µs    18.0 MB/sec
linter/default-rules/pydantic/types.py     1.03      3.4±0.01ms     7.6 MB/sec    1.00      3.3±0.00ms     7.8 MB/sec

Windows

group                                      main                                   pr
-----                                      ----                                   --
formatter/large/dataset.py                 1.00      7.8±0.02ms     5.2 MB/sec    1.05      8.2±0.04ms     5.0 MB/sec
formatter/numpy/ctypeslib.py               1.00  1573.3±15.51µs    10.6 MB/sec    1.04  1639.9±21.41µs    10.2 MB/sec
formatter/numpy/globals.py                 1.00    156.3±1.60µs    18.9 MB/sec    1.03    161.1±2.81µs    18.3 MB/sec
formatter/pydantic/types.py                1.00      3.2±0.02ms     7.9 MB/sec    1.04      3.3±0.03ms     7.6 MB/sec
linter/all-rules/large/dataset.py          1.00     16.8±0.15ms     2.4 MB/sec    1.01     17.0±0.12ms     2.4 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.01      4.3±0.03ms     3.9 MB/sec    1.00      4.3±0.02ms     3.9 MB/sec
linter/all-rules/numpy/globals.py          1.01    434.8±5.22µs     6.8 MB/sec    1.00    430.2±5.98µs     6.9 MB/sec
linter/all-rules/pydantic/types.py         1.00      7.2±0.04ms     3.6 MB/sec    1.00      7.2±0.05ms     3.6 MB/sec
linter/default-rules/large/dataset.py      1.00      8.4±0.04ms     4.8 MB/sec    1.00      8.4±0.03ms     4.8 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.00   1750.3±8.60µs     9.5 MB/sec    1.00  1756.1±11.41µs     9.5 MB/sec
linter/default-rules/numpy/globals.py      1.00    187.9±1.56µs    15.7 MB/sec    1.00    188.3±1.48µs    15.7 MB/sec
linter/default-rules/pydantic/types.py     1.01      3.8±0.03ms     6.6 MB/sec    1.00      3.8±0.03ms     6.7 MB/sec

[konstin]

Does this mean there's no elif node, just if?

[MichaReiser]

Yep. elif is represented as an else body that contains a single if statement. Rome (and Roslyn) model this very similarly where the alternate (else) is either an if statement (in which it is an else if) or a block (an else).