diff --git a/tests/unit/builder-dockerfile.bats b/tests/unit/builder-dockerfile.bats
index df1e02336..c2b41f6a2 100644
--- a/tests/unit/builder-dockerfile.bats
+++ b/tests/unit/builder-dockerfile.bats
@@ -166,7 +166,7 @@ EOF
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_AVAILABLE_PATH=$PLUGIN_AVAILABLE_PATH PLUGIN_ENABLED_PATH=$PLUGIN_ENABLED_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT $PLUGIN_ENABLED_PATH/builder-dockerfile/core-post-extract $TEST_APP $TMP_DIR HEAD"
+  run_plugin_script builder-dockerfile core-post-extract "$TEST_APP" "$TMP_DIR" HEAD
   echo "output: $output"
   echo "status: $status"
   assert_success
diff --git a/tests/unit/builder-lambda.bats b/tests/unit/builder-lambda.bats
index afbbcda9b..fa97fc977 100644
--- a/tests/unit/builder-lambda.bats
+++ b/tests/unit/builder-lambda.bats
@@ -163,7 +163,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_AVAILABLE_PATH=$PLUGIN_AVAILABLE_PATH PLUGIN_ENABLED_PATH=$PLUGIN_ENABLED_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT $PLUGIN_ENABLED_PATH/builder-lambda/core-post-extract $TEST_APP $TMP_DIR HEAD"
+  run_plugin_script builder-lambda core-post-extract "$TEST_APP" "$TMP_DIR" HEAD
   echo "output: $output"
   echo "status: $status"
   assert_success
diff --git a/tests/unit/builder-nixpacks.bats b/tests/unit/builder-nixpacks.bats
index 657fd3596..3f5e6e14e 100644
--- a/tests/unit/builder-nixpacks.bats
+++ b/tests/unit/builder-nixpacks.bats
@@ -142,7 +142,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_AVAILABLE_PATH=$PLUGIN_AVAILABLE_PATH PLUGIN_ENABLED_PATH=$PLUGIN_ENABLED_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT $PLUGIN_ENABLED_PATH/builder-nixpacks/core-post-extract $TEST_APP $TMP_DIR HEAD"
+  run_plugin_script builder-nixpacks core-post-extract "$TEST_APP" "$TMP_DIR" HEAD
   echo "output: $output"
   echo "status: $status"
   assert_success
diff --git a/tests/unit/builder-pack.bats b/tests/unit/builder-pack.bats
index 0f335053d..1a9bf5451 100644
--- a/tests/unit/builder-pack.bats
+++ b/tests/unit/builder-pack.bats
@@ -239,7 +239,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_AVAILABLE_PATH=$PLUGIN_AVAILABLE_PATH PLUGIN_ENABLED_PATH=$PLUGIN_ENABLED_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT $PLUGIN_ENABLED_PATH/builder-pack/core-post-extract $TEST_APP $TMP_DIR HEAD"
+  run_plugin_script builder-pack core-post-extract "$TEST_APP" "$TMP_DIR" HEAD
   echo "output: $output"
   echo "status: $status"
   assert_success
diff --git a/tests/unit/builder-railpack.bats b/tests/unit/builder-railpack.bats
index 82722be17..a6e99e906 100644
--- a/tests/unit/builder-railpack.bats
+++ b/tests/unit/builder-railpack.bats
@@ -153,7 +153,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_AVAILABLE_PATH=$PLUGIN_AVAILABLE_PATH PLUGIN_ENABLED_PATH=$PLUGIN_ENABLED_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT $PLUGIN_ENABLED_PATH/builder-railpack/core-post-extract $TEST_APP $TMP_DIR HEAD"
+  run_plugin_script builder-railpack core-post-extract "$TEST_APP" "$TMP_DIR" HEAD
   echo "output: $output"
   echo "status: $status"
   assert_success
diff --git a/tests/unit/resource_3.bats b/tests/unit/resource_3.bats
index 687c1a512..174d2084d 100644
--- a/tests/unit/resource_3.bats
+++ b/tests/unit/resource_3.bats
@@ -23,7 +23,7 @@ teardown() {
   echo "status: $status"
   assert_output "256m"
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT plugn trigger docker-args-process-build $TEST_APP herokuish < /dev/null"
+  run_plugn_trigger docker-args-process-build "$TEST_APP" herokuish
   echo "output: $output"
   echo "status: $status"
   assert_success
@@ -39,7 +39,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT plugn trigger docker-args-process-build $TEST_APP dockerfile < /dev/null"
+  run_plugn_trigger docker-args-process-build "$TEST_APP" dockerfile
   echo "output: $output"
   echo "status: $status"
   assert_success
@@ -55,13 +55,13 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT plugn trigger docker-args-process-build $TEST_APP pack < /dev/null"
+  run_plugn_trigger docker-args-process-build "$TEST_APP" pack
   echo "output: $output"
   echo "status: $status"
   assert_success
   assert_output_not_contains "--memory"
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT plugn trigger docker-args-process-build $TEST_APP lambda < /dev/null"
+  run_plugn_trigger docker-args-process-build "$TEST_APP" lambda
   echo "output: $output"
   echo "status: $status"
   assert_success
@@ -74,7 +74,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT plugn trigger docker-args-process-build $TEST_APP herokuish < /dev/null"
+  run_plugn_trigger docker-args-process-build "$TEST_APP" herokuish
   echo "output: $output"
   echo "status: $status"
   assert_success
@@ -87,7 +87,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT plugn trigger docker-args-process-build $TEST_APP herokuish < /dev/null"
+  run_plugn_trigger docker-args-process-build "$TEST_APP" herokuish
   echo "output: $output"
   echo "status: $status"
   assert_success
@@ -101,7 +101,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT DOKKU_OMIT_RESOURCE_ARGS=1 plugn trigger docker-args-process-build $TEST_APP herokuish < /dev/null"
+  run_plugn_trigger DOKKU_OMIT_RESOURCE_ARGS=1 docker-args-process-build "$TEST_APP" herokuish
   echo "output: $output"
   echo "status: $status"
   assert_success
diff --git a/tests/unit/test_helper.bash b/tests/unit/test_helper.bash
index 0ad154aea..60ba322e9 100644
--- a/tests/unit/test_helper.bash
+++ b/tests/unit/test_helper.bash
@@ -231,6 +231,29 @@ destroy_key() {
   rm -f /tmp/testkey* &>/dev/null || true
 }
 
+# Run a plugn trigger with the env vars plugn needs, capturing $output/$status via bats `run`.
+# Optional VAR=VAL pairs before <trigger> are forwarded as extra env vars on the bash command line.
+# Usage: run_plugn_trigger [VAR=VAL ...] <trigger> <args...>
+run_plugn_trigger() {
+  local extra_env=""
+  while [[ "$1" == *=* ]]; do
+    extra_env+=" $1"
+    shift
+  done
+  local TRIGGER="$1"
+  shift
+  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT${extra_env} plugn trigger $TRIGGER $* < /dev/null"
+}
+
+# Run a single plugin's trigger script directly so other plugins' handlers do not fire.
+# Captures $output/$status via bats `run`.
+# Usage: run_plugin_script <plugin_name> <script_name> <args...>
+run_plugin_script() {
+  local PLUGIN_NAME="$1" SCRIPT_NAME="$2"
+  shift 2
+  run /bin/bash -c "PLUGIN_PATH=$PLUGIN_PATH PLUGIN_AVAILABLE_PATH=$PLUGIN_AVAILABLE_PATH PLUGIN_ENABLED_PATH=$PLUGIN_ENABLED_PATH PLUGIN_CORE_AVAILABLE_PATH=$PLUGIN_CORE_AVAILABLE_PATH DOKKU_LIB_ROOT=$DOKKU_LIB_ROOT $PLUGIN_ENABLED_PATH/$PLUGIN_NAME/$SCRIPT_NAME $*"
+}
+
 check_urls() {
   local PATTERN="$1"
   run /bin/bash -c "dokku urls $TEST_APP | grep -E \"${PATTERN}\""