From 5d667c3e71281068d7742f41cdfe13b53fd092d7 Mon Sep 17 00:00:00 2001
From: Adam Spiers <stow@adamspiers.org>
Date: Fri, 28 Jun 2019 20:10:45 +0100
Subject: [PATCH] Make testing within Docker containers easier

---
 docker/run-stow-tests.sh | 38 +++++++++++++++++++++++++++++++++-----
 test-docker.sh           | 31 ++++++++++++++++++++++++++++++-
 2 files changed, 63 insertions(+), 6 deletions(-)

diff --git a/docker/run-stow-tests.sh b/docker/run-stow-tests.sh
index 416594c..121542c 100755
--- a/docker/run-stow-tests.sh
+++ b/docker/run-stow-tests.sh
@@ -22,11 +22,12 @@
 . /usr/local/perlbrew/etc/bashrc
 
 # Standard safety protocol
-set -euf -o pipefail
+set -ef -o pipefail
 IFS=$'\n\t'
 
-for p_version in $(perlbrew list | sed 's/ //g'); do
-    perlbrew use $p_version
+test_perl_version () {
+    perl_version="$1"
+    perlbrew use $perl_version
 
     echo $(perl --version)
 
@@ -40,6 +41,33 @@ for p_version in $(perlbrew list | sed 's/ //g'); do
     make distcheck
     perl Build.PL && ./Build build && cover -test
     ./Build distcheck
-done
+}
 
-make distclean
+if [[ -n "$LIST_PERL_VERSIONS" ]]; then
+    echo "Listing Perl versions available from perlbrew ..."
+    perlbrew list
+elif [[ -z "$PERL_VERSION" ]]; then
+    echo "Testing all versions ..."
+    for perl_version in $(perlbrew list | sed 's/ //g'); do
+        test_perl_version $perl_version
+    done
+    make distclean
+else
+    echo "Testing with Perl $PERL_VERSION"
+    # Test a specific version requested via $PERL_VERSION environment
+    # variable.  Make sure set -e doesn't cause us to bail on failure
+    # before we start an interactive shell.
+    test_perl_version $PERL_VERSION || :
+    # N.B. Don't distclean since we probably want to debug this Perl
+    # version interactively.
+    cat <<EOF
+To run a specific test, type something like:
+
+perl -Ilib -Ibin -It t/cli_options.t
+
+Code can be edited on the host and will immediately take effect inside
+this container.
+
+EOF
+    bash
+fi
diff --git a/test-docker.sh b/test-docker.sh
index f10456d..4bd446b 100755
--- a/test-docker.sh
+++ b/test-docker.sh
@@ -2,7 +2,36 @@
 
 # Test Stow across multiple Perl versions, by executing the
 # Docker image built via build-docker.sh.
+#
+# Usage: ./test-docker.sh [list | PERL_VERSION]
+#
+# If the first argument is 'list', list available Perl versions.
+# If the first argument is a Perl version, test just that version interactively.
+# If no arguments are given test all available Perl versions non-interactively.
 
 version=$( tools/get-version )
 
-docker run --rm -it -v $(pwd):$(pwd) -w $(pwd) stowtest:$version
+if [ -z "$1" ]; then
+    # Normal non-interactive run
+    docker run --rm -it \
+           -v $(pwd):$(pwd) \
+           -w $(pwd) \
+           stowtest:$version
+elif [ "$1" == list ]; then
+    # List available Perl versions
+    docker run --rm -it \
+           -v $(pwd):$(pwd) \
+           -v $(pwd)/docker/run-stow-tests.sh:/run-stow-tests.sh \
+           -w $(pwd) \
+           -e LIST_PERL_VERSIONS=1 \
+           stowtest:$version
+else
+    # Interactive run for testing / debugging a particular version
+    perl_version="$1"
+    docker run --rm -it \
+           -v $(pwd):$(pwd) \
+           -v $(pwd)/docker/run-stow-tests.sh:/run-stow-tests.sh \
+           -w $(pwd) \
+           -e PERL_VERSION=$perl_version \
+           stowtest:$version
+fi