Recommend B950 + 88 char limit instead of 80 (#2050)

[etc/vim.git] / docs / the_black_code_style.md

diff --git a/docs/the_black_code_style.md b/docs/the_black_code_style.md
index 735e9c015d70d468a723a5e6d361ed766b096c43..1cc591b80315645f603c609829063c5894d72420 100644 (file)
--- a/docs/the_black_code_style.md
+++ b/docs/the_black_code_style.md
@@ -189,22 +189,22 @@ harder to work with line lengths exceeding 100 characters. It also adversely aff
 side-by-side diff review on typical screen resolutions. Long lines also make it harder
 to present code neatly in documentation or talk slides.
 
-If you're using Flake8, you can bump `max-line-length` to 88 and forget about it.
-Alternatively, use [Bugbear](https://github.com/PyCQA/flake8-bugbear)'s B950 warning
-instead of E501 and keep the max line length at 80 which you are probably already using.
-You'd do it like this:
+If you're using Flake8, you can bump `max-line-length` to 88 and mostly forget about it.
+However, it's better if you use [Bugbear](https://github.com/PyCQA/flake8-bugbear)'s
+B950 warning instead of E501, and bump the max line length to 88 (or the `--line-length`
+you used for black), which will align more with black's _"try to respect
+`--line-length`, but don't become crazy if you can't"_. You'd do it like this:
 
 ```ini
 [flake8]
-max-line-length = 80
+max-line-length = 88
 ...
 select = C,E,F,W,B,B950
 extend-ignore = E203, E501
 ```
 
-You'll find _Black_'s own .flake8 config file is configured like this. Explanation of
-why E203 is disabled can be found further in this documentation. And if you're curious
-about the reasoning behind B950,
+Explanation of why E203 is disabled can be found further in this documentation. And if
+you're curious about the reasoning behind B950,
 [Bugbear's documentation](https://github.com/PyCQA/flake8-bugbear#opinionated-warnings)
 explains it. The tl;dr is "it's like highway speed limits, we won't bother you if you
 overdo it by a few km/h".
@@ -244,16 +244,6 @@ required due to an inner function starting immediately after.
 _Black_ will add trailing commas to expressions that are split by comma where each
 element is on its own line. This includes function signatures.
 
-Unnecessary trailing commas are removed if an expression fits in one line. This makes it
-1% more likely that your line won't exceed the allotted line length limit. Moreover, in
-this scenario, if you added another argument to your call, you'd probably fit it in the
-same line anyway. That doesn't make diffs any larger.
-
-One exception to removing trailing commas is tuple expressions with just one element. In
-this case _Black_ won't touch the single trailing comma as this would unexpectedly
-change the underlying data type. Note that this is also the case when commas are used
-while indexing. This is a tuple in disguise: `numpy_array[3, ]`.
-
 One exception to adding trailing commas is function signatures containing `*`, `*args`,
 or `**kwargs`. In this case a trailing comma is only safe to use on Python 3.6. _Black_
 will detect if your file is already 3.6+ only and use trailing commas in this situation.
@@ -262,6 +252,10 @@ in function signatures that have stars in them. In other words, if you'd like a
 comma in this situation and _Black_ didn't recognize it was safe to do so, put it there
 manually and _Black_ will keep it.
 
+A pre-existing trailing comma informs _Black_ to always explode contents of the current
+bracket pair into one item per line. Read more about this in the
+[Pragmatism](#pragmatism) section below.
+
 ### Strings
 
 _Black_ prefers double quotes (`"` and `"""`) over single quotes (`'` and `'''`). It
@@ -444,6 +438,9 @@ into one item per line.
 How do you make it stop? Just delete that trailing comma and _Black_ will collapse your
 collection into one line if it fits.
 
+If you must, you can recover the behaviour of early versions of Black with the option
+`--skip-magic-trailing-comma` / `-C`.
+
 ### r"strings" and R"strings"
 
 _Black_ normalizes string quotes as well as string prefixes, making them lowercase. One