Remove linked app from links file when destroying app

tests/bin/sudo

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+exit 0

tests/hook_pre_delete.bats

@@ -0,0 +1,20 @@
+#!/usr/bin/env bats
+load test_helper
+
+setup() {
+  dokku apps:create my_app >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:create" l >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app >&2
+}
+
+teardown() {
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app >&2
+  dokku --force "$PLUGIN_COMMAND_PREFIX:destroy" l >&2
+  rm "$DOKKU_ROOT/my_app" -rf
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:hook:pre-delete) removes app from links file when destroying app" {
+  [[ -n $(< "$PLUGIN_DATA_ROOT/l/LINKS") ]]
+  dokku --force apps:destroy my_app
+  [[ -z $(< "$PLUGIN_DATA_ROOT/l/LINKS") ]]
+}

tests/setup.sh

@@ -1,6 +1,8 @@
 #!/usr/bin/env bash
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/test_helper.bash"
 
+BIN_STUBS="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/bin"
+
 if [[ ! -d $DOKKU_ROOT ]]; then
   git clone https://github.com/progrium/dokku.git $DOKKU_ROOT > /dev/null
 fi
@@ -13,3 +15,10 @@ cd -
 rm -rf $DOKKU_ROOT/plugins/service
 mkdir -p $DOKKU_ROOT/plugins/service
 find ./ -maxdepth 1 -type f -exec cp '{}' $DOKKU_ROOT/plugins/service \;
+
+if [[ ! -f $BIN_STUBS/plugn ]]; then
+  wget -O- "$PLUGN_URL" | tar xzf - -C "$BIN_STUBS"
+  plugn init
+  ln -s "$DOKKU_ROOT"/plugins/* "$DOKKU_ROOT"/plugins/available
+  ln -s "$DOKKU_ROOT"/plugins/* "$DOKKU_ROOT"/plugins/enabled
+fi

tests/test_helper.bash

@@ -10,6 +10,7 @@ export PLUGIN_AVAILABLE_PATH="$PLUGIN_PATH"
 export PLUGIN_CORE_AVAILABLE_PATH="$PLUGIN_PATH"
 export POSTGRES_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/fixtures"
 export PLUGIN_DATA_ROOT="$POSTGRES_ROOT"
+export PLUGN_URL="https://github.com/progrium/plugn/releases/download/v0.1.0/plugn_0.1.0_linux_x86_64.tgz"
 
 mkdir -p "$PLUGIN_DATA_ROOT"
 rm -rf "${PLUGIN_DATA_ROOT:?}"/*