WIP MIL-007: fetch the framework's qc, follow links, default configuration files

- git submodule update --init --recursive after adding or reusing the framework
- Follow links to the script so SCRIPT_DIR and the checkout are the real ones
- config.env and .env: --config/--env, else ./ in the working folder, else the checkout's
- Name the files used; a file from the working folder needs a yes before any request
- MIL-007 accepted; test fixtures for the qc checklists; tests/test-launch.sh

Work in progress: the README section is not written yet, and four tests of
test-launch.sh fail and two shellcheck warnings remain; they are fixed next.

Task: MIL-007#1
Task: MIL-007#2
Refs #47
Refs #48
Refs #51

src/create-project.sh

@@ -86,18 +86,39 @@ if ((BASH_VERSINFO[0] < 4 || (BASH_VERSINFO[0] == 4 && BASH_VERSINFO[1] < 4)));
 fi
 
 # Where this script lives; the library files and the project root are found
-# from here, never from the current directory.
-readonly SCRIPT_FILE="${BASH_SOURCE[0]}"
-case "${BASH_SOURCE[0]}" in
-  */*) script_path_dir="${BASH_SOURCE[0]%/*}" ;;
+# from here, never from the current directory. A link to the script (a
+# command in a folder on PATH) is followed to the real file, however many
+# links lie on the way; readlink without -f exists on Linux, macOS and Git
+# Bash alike.
+script_path="${BASH_SOURCE[0]}"
+script_link_count=0
+while [[ -L $script_path ]]; do
+  ((++script_link_count <= 40)) || {
+    printf 'error: too many links when following %s\n' "${BASH_SOURCE[0]}" >&2
+    exit 1
+  }
+  script_link_target="$(readlink -- "$script_path")"
+  case "$script_link_target" in
+    /*) script_path="$script_link_target" ;;
+    *)
+      case "$script_path" in
+        */*) script_path="${script_path%/*}/$script_link_target" ;;
+        *) script_path="$script_link_target" ;;
+      esac
+      ;;
+  esac
+done
+readonly SCRIPT_FILE="$script_path"
+case "$script_path" in
+  */*) script_path_dir="${script_path%/*}" ;;
   *) script_path_dir="." ;;
 esac
-SCRIPT_DIR="$(cd "$script_path_dir" && pwd)"
+SCRIPT_DIR="$(cd -P "$script_path_dir" && pwd -P)"
 readonly SCRIPT_DIR
-unset script_path_dir
-# The script lives in src/; the configuration files live one level up, in
-# the project root, next to config.env.example and .env.example.
-PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+unset script_path script_path_dir script_link_count script_link_target
+# The script lives in src/; the checkout is one level up, next to
+# config.env.example and .env.example.
+PROJECT_ROOT="$(cd -P "$SCRIPT_DIR/.." && pwd -P)"
 readonly PROJECT_ROOT
 
 # shellcheck source=lib/constants.sh
@@ -163,6 +184,7 @@ main() {
   trap finish EXIT
   is_valid_repo_name "$PROJECT_NAME" ||
     die "REPOFOUNDRY_NAME is not a valid project name"
+  WORKING_FOLDER="$(pwd -P)"
   parse_args "$@"
   check_tools
   setup_temp_dir