Add --debug flag to test driver

This is easier than the old method of adding `DEBUG=true` to the top of
test files.

test/README.md

@@ -51,8 +51,8 @@ edits on your host machine). You can run the test suite by `cd /dotbot/test`
 and then running `./test`. Selected tests can be run by passing paths to the
 tests as arguments, e.g. `./test tests/create.bash tests/defaults.bash`.
 
-To debug tests, you can prepend the line `DEBUG=true` as the first line to any
-individual test (a `.bash` file inside `test/tests`). This will enable printing
+To debug tests, you can run the test driver with the `--debug` (or `-d` short
+form) flag, e.g. `./test --debug tests/link-if.bash`. This will enable printing
 stdout/stderr.
 
 When finished with testing, it is good to shut down the virtual machine by

test/driver-lib.bash

@@ -60,7 +60,7 @@ run_test() {
     tests_run=$((tests_run + 1))
     printf '[%d/%d] (%s)\n' "${tests_run}" "${tests_total}" "${1}"
     cleanup
-    if (cd "${BASEDIR}/test/tests" && HOME=~/fakehome DOTBOT_TEST=true bash "${1}"); then
+    if (cd "${BASEDIR}/test/tests" && HOME=~/fakehome DEBUG=${2} DOTBOT_TEST=true bash "${1}"); then
         pass
     else
         fail

test/test

@@ -10,6 +10,23 @@ start="$(date +%s)"
 
 check_env
 
+# parse flags; must come before positional arguments
+POSITIONAL=()
+DEBUG=false
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -d|--debug)
+            DEBUG=true
+            shift
+            ;;
+        *)
+            POSITIONAL+=("$1")
+            shift
+            ;;
+    esac
+done
+set -- "${POSITIONAL[@]}" # restore positional arguments
+
 declare -a tests=()
 
 if [ $# -eq 0 ]; then
@@ -20,10 +37,10 @@ else
     tests=("$@")
 fi
 
-initialize "${#tests[@]}" "${VERSION}"
+initialize "${#tests[@]}"
 
 for file in "${tests[@]}"; do
-    run_test "$(basename "${file}")" "${VERSION}"
+    run_test "$(basename "${file}")" "${DEBUG}"
 done
 
 if report; then

test/test-lib.bash

@@ -1,4 +1,3 @@
-DEBUG=${DEBUG:-false}
 DOTBOT_EXEC="${BASEDIR}/bin/dotbot"
 DOTFILES="${HOME}/dotfiles"
 INSTALL_CONF='install.conf.yaml'