pythonImportsCheckHook: lint with ShellCheck

pkgs/development/interpreters/python/hooks/python-imports-check-hook.sh

@@ -1,23 +1,28 @@
+# shellcheck shell=bash
+
 # Setup hook for checking whether Python imports succeed
 echo "Sourcing python-imports-check-hook.sh"
 
 pythonImportsCheckPhase() {
     echo "Executing pythonImportsCheckPhase"
 
-    if [ -n "${pythonImportsCheck[*]-}" ]; then
+    if [[ -n "${pythonImportsCheck[*]-}" ]]; then
         echo "Check whether the following modules can be imported: ${pythonImportsCheck[*]}"
         # shellcheck disable=SC2154
         pythonImportsCheckOutput="$out"
-        if [ -n "${python-}" ]; then
+        if [[ -n "${python-}" ]]; then
             echo "Using python specific output \$python for imports check"
             pythonImportsCheckOutput=$python
         fi
         export PYTHONPATH="$pythonImportsCheckOutput/@pythonSitePackages@:$PYTHONPATH"
+        # Python modules and namespaces names are Python identifiers, which must not contain spaces.
+        # See https://docs.python.org/3/reference/lexical_analysis.html
+        # shellcheck disable=SC2048,SC2086
         (cd "$pythonImportsCheckOutput" && @pythonCheckInterpreter@ -c 'import sys; import importlib; list(map(lambda mod: importlib.import_module(mod), sys.argv[1:]))' ${pythonImportsCheck[*]})
     fi
 }
 
-if [ -z "${dontUsePythonImportsCheck-}" ]; then
+if [[ -z "${dontUsePythonImportsCheck-}" ]]; then
     echo "Using pythonImportsCheckPhase"
     appendToVar preDistPhases pythonImportsCheckPhase
 fi