ci: Allow for single exercise test exection (#849)

Author: tomasnorre

README.md

@@ -40,6 +40,22 @@ composer test:run
 
 This is included in `composer ci` to run the CI checks locally.
 
+### Run a specific test
+
+If you want to run tests for one specific exercise, you can do it with following cli command.
+
+```shell
+composer test:run -- exercise-name
+# e.g
+composer test:run -- book-store
+```
+
+If you want to run all starting with let's say 'b' you can run
+
+```shell
+composer test:run -- "b*"
+```
+
 ## Running Style Checker
 
 This project uses a slightly [modified][local-file-phpcs-config] version of [PSR-12].

bin/test.sh

@@ -13,15 +13,20 @@ file_ext="php"
 function main {
   has_failures=0
 
-  all_practice_exercise_dirs=$(find ./exercises/practice -maxdepth 1 -mindepth 1 -type d | sort)
+  name_filter=()
+  if [ $# -ge 1 ] && [ -n "$1" ]; then
+    name_filter=("-name" "$1")
+  fi
+
+  all_practice_exercise_dirs=$(find ./exercises/practice -maxdepth 1 -mindepth 1 -type d "${name_filter[@]}" | sort)
   for exercise_dir in $all_practice_exercise_dirs; do
     test "${exercise_dir}" "example"
     if [[ $? -ne 0 ]]; then
       has_failures=1
     fi
   done
 
-  all_concept_exercise_dirs=$(find ./exercises/concept -maxdepth 1 -mindepth 1 -type d | sort)
+  all_concept_exercise_dirs=$(find ./exercises/concept -maxdepth 1 -mindepth 1 -type d "${name_filter[@]}" | sort)
   for exercise_dir in $all_concept_exercise_dirs; do
     test "${exercise_dir}" "exemplar"
     if [[ $? -ne 0 ]]; then