Get rid of duplication by adding an optional argument

I evaluated `getopt` and `getopts` and
then decided to keep it simple and just force clients
to pass --no-build as the fourth argument.

Author: fapdash

bin/run-in-docker-without-build.sh

@@ -8,6 +8,7 @@
 # $1: exercise slug
 # $2: path to solution folder
 # $3: path to output directory
+# $4: [--no-build]: Don't run docker build
 
 # Output:
 # Writes the test results to a results.json file in the passed-in output directory.
@@ -17,8 +18,10 @@
 # ./bin/run-in-docker.sh two-fer path/to/solution/folder/ path/to/output/directory/
 
 # If any required arguments is missing, print the usage and exit
-if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ]; then
-    echo "usage: ./bin/run-in-docker.sh exercise-slug path/to/solution/folder/ path/to/output/directory/"
+if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ] || [ "${4:---no-build}" != "--no-build" ]; then
+    echo "usage: ./bin/run-in-docker.sh exercise-slug path/to/solution/folder/ path/to/output/directory/ [--no-build]"
+    echo "All arguments are positional, including the optional --no-build flag"
+    echo "Pass in --no-build as fourth argument to stop the Docker build from running"
     exit 1
 fi
 
@@ -29,8 +32,10 @@ output_dir=$(realpath "${3%/}")
 # Create the output directory if it doesn't exist
 mkdir -p "${output_dir}"
 
-# Build the Docker image
-bin/build-crac-checkpoint-image.sh
+if [ "$4" != "--no-build" ]; then
+    # Build the Docker image
+    bin/build-crac-checkpoint-image.sh
+fi
 
 # Run the Docker image using the settings mimicking the production environment
 docker run \

bin/run-in-docker.sh

@@ -1,7 +1,7 @@
 #! /bin/bash -e
 
 # Synopsis:
-# Test the test runner Docker image by running it against a predefined set of 
+# Test the test runner Docker image by running it against a predefined set of
 # solutions with an expected output.
 # The test runner Docker image is built automatically.
 
@@ -24,7 +24,7 @@ for test_dir in tests/*; do
     results_file_path="${test_dir_path}/results.json"
     expected_results_file_path="${test_dir_path}/expected_results.json"
 
-    bin/run-in-docker-without-build.sh "${test_dir_name}" "${test_dir_path}" "${test_dir_path}"
+    bin/run-in-docker.sh "${test_dir_name}" "${test_dir_path}" "${test_dir_path}" --no-build
 
     # Normalize the results file
     sed -i "s~${test_dir_path}~/solution~g" "${results_file_path}"