stdenv: support multi-char separators in concatStringsSep

wolfgangwalther · wolfgangwalther · commit 56b09628e333 · 2024-11-30T16:38:02.000+01:00
One prominent use-case for this is pytestCheckHook. This will help
making it work with structuredAttrs in the future.
diff --git a/pkgs/development/interpreters/python/hooks/pytest-check-hook.sh b/pkgs/development/interpreters/python/hooks/pytest-check-hook.sh
@@ -4,37 +4,14 @@ echo "Sourcing pytest-check-hook"
 declare -ar disabledTests
 declare -a disabledTestPaths
 
-function _concatSep {
-    local result
-    local sep="$1"
-    local -n arr=$2
-    for index in ${!arr[*]}; do
-        if [ $index -eq 0 ]; then
-            result="${arr[index]}"
-        else
-            result+=" $sep ${arr[index]}"
-        fi
-    done
-    echo "$result"
-}
-
-function _pytestComputeDisabledTestsString() {
-    declare -a tests
-    local tests=($1)
-    local prefix="not "
-    prefixed=("${tests[@]/#/$prefix}")
-    result=$(_concatSep "and" prefixed)
-    echo "$result"
-}
-
 function pytestCheckPhase() {
     echo "Executing pytestCheckPhase"
     runHook preCheck
 
     # Compose arguments
     args=" -m pytest"
     if [ -n "$disabledTests" ]; then
-        disabledTestsString=$(_pytestComputeDisabledTestsString "${disabledTests[@]}")
+        disabledTestsString="not $(concatStringsSep " and not " disabledTests)"
         args+=" -k \""$disabledTestsString"\""
     fi
 
diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
@@ -432,6 +432,11 @@ concatTo() {
 # $ flags=("lorem ipsum" "dolor" "sit amet")
 # $ concatStringsSep ";" flags
 # lorem ipsum;dolor;sit amet
+#
+# Also supports multi-character separators;
+# $ flags=("lorem ipsum" "dolor" "sit amet")
+# $ concatStringsSep " and " flags
+# lorem ipsum and dolor and sit amet
 concatStringsSep() {
     local sep="$1"
     local name="$2"
@@ -443,11 +448,15 @@ concatStringsSep() {
                 echo "concatStringsSep(): ERROR: trying to use concatStringsSep on an associative array." >&2
                 return 1 ;;
             -a*)
-                local IFS="$sep"
-                echo -n "${nameref[*]}" ;;
+                # \036 is the "record separator" character. We assume that this will never need to be part of
+                # an argument string we create here. If anyone ever hits this limitation: Feel free to refactor.
+                local IFS=$'\036' ;;
             *)
-                echo -n "${nameref// /"${sep}"}" ;;
+                local IFS=" " ;;
+
         esac
+        local ifs_separated="${nameref[*]}"
+        echo -n "${ifs_separated//"$IFS"/"$sep"}"
     fi
 }
 
diff --git a/pkgs/test/stdenv/default.nix b/pkgs/test/stdenv/default.nix
@@ -161,6 +161,14 @@ let
           arrayWithSep="$(concatStringsSep "&" array)"
           [[ "$arrayWithSep" == "lorem ipsum&dolor&sit amet" ]] || (echo "'\$arrayWithSep' was not 'lorem ipsum&dolor&sit amet'" && false)
 
+          array=("lorem ipsum" "dolor" "sit amet")
+          arrayWithSep="$(concatStringsSep "++" array)"
+          [[ "$arrayWithSep" == "lorem ipsum++dolor++sit amet" ]] || (echo "'\$arrayWithSep' was not 'lorem ipsum++dolor++sit amet'" && false)
+
+          array=("lorem ipsum" "dolor" "sit amet")
+          arrayWithSep="$(concatStringsSep " and " array)"
+          [[ "$arrayWithSep" == "lorem ipsum and dolor and sit amet" ]] || (echo "'\$arrayWithSep' was not 'lorem ipsum and dolor and sit amet'" && false)
+
           touch $out
         '';
       };
