Add tags option

README.md

@@ -194,6 +194,19 @@ Upload test results to Test Engine. Default: `true`. Set to `false` if you use t
 
 Requires bktec 2.7.0 or later.
 
+#### `tags` (optional, array of strings)
+
+Tags to attach to the uploaded test results. Each tag is a `key=value` string.
+
+```yaml
+plugins:
+  - tests#v1.0.0:
+      test-runner: rspec
+      tags:
+        - "language.version=3.3"
+        - "os=linux"
+```
+
 #### `debug-enabled` (optional, boolean)
 
 Enable verbose output.

hooks/environment

@@ -42,6 +42,25 @@ for prop in "${PROPERTIES[@]}"; do
   fi
 done
 
+# Buildkite exposes array properties as indexed env vars (TAGS_0, TAGS_1, ...),
+# but a single string value is exposed without an index (TAGS). So we need to handle both.
+if [[ -n "${BUILDKITE_PLUGIN_TESTS_TAGS:-}" ]]; then
+  export "BUILDKITE_TEST_ENGINE_TAGS=${BUILDKITE_PLUGIN_TESTS_TAGS}"
+  exported_vars+=("BUILDKITE_TEST_ENGINE_TAGS")
+elif [[ -n "${BUILDKITE_PLUGIN_TESTS_TAGS_0:-}" ]]; then
+  declare -a tags=()
+  i=0
+  while true; do
+    plugin_var="BUILDKITE_PLUGIN_TESTS_TAGS_${i}"
+    [[ -z "${!plugin_var:-}" ]] && break
+    tags+=("${!plugin_var}")
+    i=$(( i + 1 ))
+  done
+  joined=$(IFS=','; echo "${tags[*]}")
+  export "BUILDKITE_TEST_ENGINE_TAGS=$joined"
+  exported_vars+=("BUILDKITE_TEST_ENGINE_TAGS")
+fi
+
 # TODO: 
 # Update docker and docker-compose plugins to propagate these env vars
 # so we don't have to write them to BUILDKITE_ENV_FILE here.

plugin.yml

@@ -40,6 +40,12 @@ configuration:
       description: >-
         Upload test results to Test Engine. Default: true. Set to false if you use the test collectors for richer
         data collection, or if you want to handle the upload yourself.
+    tags:
+      type: array
+      description: >-
+        Tags to attach to the uploaded test results. Each tag is a key=value string (e.g. "env=production").
+      items:
+        type: string
 
     # Test runner
     test-runner:

tests/environment.bats

@@ -32,3 +32,43 @@ setup() {
   run cat ${BUILDKITE_ENV_FILE}
   assert_output "BUILDKITE_TEST_ENGINE_UPLOAD_RESULTS=false"
 }
+
+@test "passes a tag string directly to bktec" {
+  export BUILDKITE_PLUGIN_TESTS_TAGS="language.version=3.3"
+  export BUILDKITE_ENV_FILE=$(mktemp)
+
+  run $PWD/hooks/environment
+
+  run cat ${BUILDKITE_ENV_FILE}
+  assert_line "BUILDKITE_TEST_ENGINE_TAGS=language.version=3.3"
+}
+
+@test "passes a single tag to bktec" {
+  export BUILDKITE_PLUGIN_TESTS_TAGS_0="language.version=3.3"
+  export BUILDKITE_ENV_FILE=$(mktemp)
+
+  run $PWD/hooks/environment
+
+  run cat ${BUILDKITE_ENV_FILE}
+  assert_line "BUILDKITE_TEST_ENGINE_TAGS=language.version=3.3"
+}
+
+@test "passes multiple tags to bktec as comma-separated values" {
+  export BUILDKITE_PLUGIN_TESTS_TAGS_0="language.version=3.3"
+  export BUILDKITE_PLUGIN_TESTS_TAGS_1="os=linux"
+  export BUILDKITE_ENV_FILE=$(mktemp)
+
+  run $PWD/hooks/environment
+
+  run cat ${BUILDKITE_ENV_FILE}
+  assert_line "BUILDKITE_TEST_ENGINE_TAGS=language.version=3.3,os=linux"
+}
+
+@test "does not set tags env var when no tags provided" {
+  export BUILDKITE_ENV_FILE=$(mktemp)
+
+  run $PWD/hooks/environment
+
+  run cat ${BUILDKITE_ENV_FILE}
+  refute_line --partial "BUILDKITE_TEST_ENGINE_TAGS"
+}