Allow verifying prerequisites!

examples

@@ -44,4 +44,12 @@
   _bad-message - Bad Message
 }
 
+_verify-prerequisites() {
+  if ! [[ -f /tmp/banana ]]; then
+    _bad-message There\'s not enough banana
+    _bad-message touch /tmp/banana to continue
+    exit 1
+  fi
+}
+
 source ⚡️

readme.md

@@ -119,7 +119,7 @@ $ echo '
 #!/usr/bin/env bash
 
 _verify-prerequisites() {
-  docker ps &> /dev/null || echo 'Not enough docker'
+  docker ps &> /dev/null || (echo 'Not enough docker'; exit 1)
 }
 
 ⚡️ubuntu() {

test/test-prereqs

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+testShouldBailIfRequirementsNotMet() {
+  echo '
+  #!/usr/bin/env bash
+
+  _verify-prerequisites() { false; }
+  ⚡️hello() { echo "Hello, World!" ; }
+  ' > go
+
+  echo "source $REPO_ROOT/⚡️" >> go
+  chmod +x go
+
+  try ./go
+  assertNotContains "$STDOUT" "hello"
+  assertEquals 1 "$EXIT_CODE"
+}
+
+testShouldNotBailWhenPrereqsAreAllGood() {
+  echo '
+  #!/usr/bin/env bash
+
+  _verify-prerequisites() { true; }
+  ⚡️hello() { echo "Hello, World!" ; }
+  ' > go
+
+  echo "source $REPO_ROOT/⚡️" >> go
+  chmod +x go
+
+  try ./go
+  assertContains "$STDOUT" "hello"
+  assertEquals 0 "$EXIT_CODE"
+}
+
+source $(dirname $0)/runner

⚡️

@@ -40,4 +40,6 @@ _bad-message() {
   echo -e "\e[31m$@\e[0m"
 }
 
+[[ $(type -t _verify-prerequisites) == "function" ]] && ! _verify-prerequisites && exit 1
+
 main "$@"