diff options
author | Sandro <sandro.jaeckel@gmail.com> | 2021-10-05 23:13:26 +0200 |
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committer | GitHub <noreply@github.com> | 2021-10-05 23:13:26 +0200 |
commit | f289d93a41cf9888f0ade3357b0d8df9104505dd (patch) | |
tree | 31ee725c3a0cb16e12d4944af2ffd1d944b8731a | |
parent | 704b174d77f2a2e2c185739ba728944aedb34ff6 (diff) |
doc/contributing: add lib.optional (#121251)
Co-authored-by: Cole Helbling <cole.e.helbling@outlook.com>
-rw-r--r-- | doc/contributing/coding-conventions.chapter.md | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/doc/contributing/coding-conventions.chapter.md b/doc/contributing/coding-conventions.chapter.md index 85c8626bd99c4..7a8e7741a3302 100644 --- a/doc/contributing/coding-conventions.chapter.md +++ b/doc/contributing/coding-conventions.chapter.md @@ -181,6 +181,21 @@ rev = "${version}"; ``` +- Filling lists condionally _should_ be done with `lib.optional(s)` instead of using `if cond then [ ... ] else null` or `if cond then [ ... ] else [ ]`. + + ```nix + buildInputs = lib.optional stdenv.isDarwin iconv; + ``` + + instead of + + ```nix + buildInputs = if stdenv.isDarwin then [ iconv ] else null; + ``` + + As an exception, an explicit conditional expression with null can be used when fixing a important bug without triggering a mass rebuild. + If this is done a follow up pull request _should_ be created to change the code to `lib.optional(s)`. + - Arguments should be listed in the order they are used, with the exception of `lib`, which always goes first. ## Package naming {#sec-package-naming} |