add Docker tests for older bash-es

4 files changed, 70 insertions, 3 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f4954c4..2bfb964 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,7 +6,7 @@ on:
   workflow_dispatch:
 
 jobs:
-  test:
+  test_local:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
@@ -26,4 +26,18 @@ jobs:
         # with ancient utilities that come with the actual macOS.
 
       - name: Test
-        run: ./test/test.sh
+        run: make test
+
+  test_docker:
+    strategy:
+      matrix:
+        # Keep in sync with those in Makefile:
+        distro: [xenial, focal]
+    runs-on: ubuntu-latest
+    name: 'Test / Docker / ${{ matrix.distro }}'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Test
+        run: make 'test/docker/${{ matrix.distro }}'
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..cf78947
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,45 @@
+MAKEFLAGS += --no-builtin-rules --no-builtin-variables --warn-undefined-variables
+unexport MAKEFLAGS
+.DEFAULT_GOAL := all
+.DELETE_ON_ERROR:
+.SUFFIXES:
+SHELL := bash
+.SHELLFLAGS := -eu -o pipefail -c
+
+escape = $(subst ','\'',$(1))
+
+define noexpand
+ifeq ($$(origin $(1)),environment)
+    $(1) := $$(value $(1))
+endif
+ifeq ($$(origin $(1)),environment override)
+    $(1) := $$(value $(1))
+endif
+ifeq ($$(origin $(1)),command line)
+    override $(1) := $$(value $(1))
+endif
+endef
+
+.PHONY: DO
+DO:
+
+.PHONY: all
+all: test
+
+.PHONY: test
+test: test/local
+
+.PHONY: test/all
+test/all: test/local test/docker
+
+.PHONY: test/local
+test/local:
+	./test/test.sh
+
+test/docker/%: DO
+	cd test && \
+		DISTRO='$*' docker-compose run --rm test && \
+		docker-compose down -v
+
+.PHONY: test/docker
+test/docker: test/docker/xenial test/docker/focal
diff --git a/test/docker-compose.yml b/test/docker-compose.yml
new file mode 100644
index 0000000..2d7f094
--- /dev/null
+++ b/test/docker-compose.yml
@@ -0,0 +1,7 @@
+version: '3'
+services:
+  test:
+    image: "ubuntu:${DISTRO:-xenial}"
+    volumes:
+      - ../:/src
+    command: /src/test/test.sh
diff --git a/test/test.sh b/test/test.sh
index 05c5d65..e28f112 100755
--- a/test/test.sh
+++ b/test/test.sh
@@ -1,7 +1,8 @@
 #!/usr/bin/env bash
 
 set -o errexit -o nounset -o pipefail
-shopt -s inherit_errexit lastpipe
+shopt -s inherit_errexit 2> /dev/null || true
+shopt -s lastpipe
 
 script_dir="$( dirname -- "${BASH_SOURCE[0]}" )"
 script_dir="$( cd -- "$script_dir" && pwd )"