From b15d5cc6ee566127a634fcad74fef7e251f17878 Mon Sep 17 00:00:00 2001 From: Jade Lovelace Date: Fri, 9 Aug 2024 23:25:20 -0700 Subject: [PATCH] nix: remove explosions if you have a window size less than four Turns out strings do not like being resized to -4. This was discovered while messing with the tests to remove unbuffer and trying stdbuf instead. Turns out that was not the right approach. This basically rewrites the handling of this case to be much more correct, and fixes a bug where with small window sizes where it would ALSO truncate the attr names in addition to the optional descriptions. Change-Id: Ifd1beeaffdb47cbb5f4a462b183fcb6c0ff6c524 --- src/nix/flake.cc | 40 ++++++++++++++++++++++----------- tests/functional/flakes/show.sh | 19 +++++++++++++--- 2 files changed, 43 insertions(+), 16 deletions(-) diff --git a/src/nix/flake.cc b/src/nix/flake.cc index 5ea9e077b..d4eca86b8 100644 --- a/src/nix/flake.cc +++ b/src/nix/flake.cc @@ -3,7 +3,7 @@ #include "common-args.hh" #include "shared.hh" #include "eval.hh" -#include "eval-inline.hh" +#include "eval-inline.hh" // IWYU pragma: keep #include "eval-settings.hh" #include "flake/flake.hh" #include "get-drvs.hh" @@ -17,8 +17,8 @@ #include "markdown.hh" #include "terminal.hh" +#include #include -#include #include using namespace nix; @@ -1258,24 +1258,38 @@ struct CmdFlakeShow : FlakeCommand, MixJSON attrPath.size() == 3 && attrPathS[0] == "checks" ? "derivation" : attrPath.size() >= 1 && attrPathS[0] == "hydraJobs" ? "derivation" : "package"; + + std::string output = fmt("%s: %s '%s'", headerPrefix, type, name); + if (description && !description->empty()) { // Trim the string and only display the first line of the description. auto desc = nix::trim(*description); auto firstLineDesc = desc.substr(0, desc.find('\n')); + // three separators, two quotes + constexpr auto quotesAndSepsWidth = 3 + 2; - std::string output = fmt("%s: %s '%s' - '%s'", headerPrefix, type, name, firstLineDesc); - if (output.size() > getWindowSize().second) { - // we resize to 4 less then the window size to account for the "...'" we append to - // the final string, we also include the ' since that is removed when we truncate the string - output.resize(getWindowSize().second - 4); - output.append("...'"); + int screenWidth = isOutputARealTerminal(StandardOutputStream::Stdout) + ? getWindowSize().second + : std::numeric_limits::max(); + + // FIXME: handle utf8 visible width properly once we get KJ which has utf8 support + // technically filterANSIEscapes knows how to do this but there is absolutely + // no clear usage of it that would actually let us do this layout. + int spaceForDescription = screenWidth - output.size() - quotesAndSepsWidth; + + if (spaceForDescription <= 0) { + // do nothing, it is going to wrap no matter what, and it's better to output *something* + } else { + const char *ellipsis = ""; + if (spaceForDescription < firstLineDesc.size()) { + // subtract one to make space for the ellipsis + firstLineDesc.resize(spaceForDescription - 1); + ellipsis = "…"; + } + output.append(fmt(" - '%s%s'", firstLineDesc, ellipsis)); } - - logger->cout("%s", output.c_str()); - } - else { - logger->cout("%s: %s '%s'", headerPrefix, type, name); } + logger->cout("%s", output); } }; diff --git a/tests/functional/flakes/show.sh b/tests/functional/flakes/show.sh index 857c77ae1..3461597ee 100644 --- a/tests/functional/flakes/show.sh +++ b/tests/functional/flakes/show.sh @@ -107,10 +107,23 @@ EOF runinpty sh -c ' stty rows 20 cols 100 - nix flake show > show-output.txt -' + TERM=xterm-256color NOCOLOR=1 nix flake show +' > show-output.txt + test "$(awk -F '[:] ' '/aNoDescription/{print $NF}' ./show-output.txt)" = "package 'simple'" test "$(awk -F '[:] ' '/bOneLineDescription/{print $NF}' ./show-output.txt)" = "package 'simple' - 'one line'" test "$(awk -F '[:] ' '/cMultiLineDescription/{print $NF}' ./show-output.txt)" = "package 'simple' - 'line one'" -test "$(awk -F '[:] ' '/dLongDescription/{print $NF}' ./show-output.txt)" = "package 'simple' - 'abcdefghijklmnopqrs...'" +test "$(awk -F '[:] ' '/dLongDescription/{print $NF}' ./show-output.txt)" = "package 'simple' - 'abcdefghijklmnopqrstu…'" +test "$(awk -F '[:] ' '/eEmptyDescription/{print $NF}' ./show-output.txt)" = "package 'simple'" + +# validate that having a broken window size does not cause anything to explode +# and that descriptions are just not printed if there is no space at all +runinpty sh -c ' + stty rows 0 cols 0 + TERM=xterm-256color NOCOLOR=1 nix flake show +' > show-output.txt +test "$(awk -F '[:] ' '/aNoDescription/{print $NF}' ./show-output.txt)" = "package 'simple'" +test "$(awk -F '[:] ' '/bOneLineDescription/{print $NF}' ./show-output.txt)" = "package 'simple'" +test "$(awk -F '[:] ' '/cMultiLineDescription/{print $NF}' ./show-output.txt)" = "package 'simple'" +test "$(awk -F '[:] ' '/dLongDescription/{print $NF}' ./show-output.txt)" = "package 'simple'" test "$(awk -F '[:] ' '/eEmptyDescription/{print $NF}' ./show-output.txt)" = "package 'simple'"