tests: Improve diagnostics and robustness of test shell scripts (#81)

Motivation
----------

Tests scripts are used by GitHub Actions and when running tests locally.
They should have consistent structures, clean up after themselves and
print useful messages so that failures can be diagnosed.

Modifications
-------------

* Update all test scripts to use the same structure and cleanup options
as `run-integration-tests.sh`
* Add better diagnostic messages

Result
------

Test failures will be easier to diagnose

Test Plan
---------

Existing tests continue to pass.

Author: euanh

scripts/test-elf-detection.sh

@@ -1,23 +1,70 @@
 #!/usr/bin/env bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftContainerPlugin open source project
+##
+## Copyright (c) 2025 Apple Inc. and the SwiftContainerPlugin project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftContainerPlugin project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
 
-set -ex -o pipefail
+#
+# This script assumes that the Static Linux SDK has already been installed
+#
 
+log() { printf -- "** %s\n" "$*" >&2; }
+error() { printf -- "** ERROR: %s\n" "$*" >&2; }
+fatal() { error "$@"; exit 1; }
+
+set -euo pipefail
+
+RUNTIME=${RUNTIME-"docker"}
+
+#
+# Create a test package
+#
 PKGPATH=$(mktemp -d)
 swift package --package-path "$PKGPATH" init --type executable --name hello
 
+cleanup() {
+  log "Deleting temporary package $PKGPATH"
+  rm -rf "$PKGPATH"
+}
+trap cleanup EXIT
+
+#
 # Build and package an x86_64 binary
+#
 swift build --package-path "$PKGPATH" --swift-sdk x86_64-swift-linux-musl
-file "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello"
+FILETYPE=$(file "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello")
+log "Executable type: $FILETYPE"
+
 IMGREF=$(swift run containertool --repository localhost:5000/elf_test "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello" --from scratch)
-docker pull "$IMGREF"
-docker inspect "$IMGREF" --format "{{.Architecture}}" | grep amd64
-echo x86_64 detection: PASSED
+$RUNTIME pull "$IMGREF"
+IMGARCH=$($RUNTIME inspect "$IMGREF" --format "{{.Architecture}}")
+if [ "$IMGARCH" = "amd64" ] ; then
+  log "x86_64 detection: PASSED"
+else
+  fatal "x86_64 detection: FAILED - image architecture was $IMGARCH; expected amd64"
+fi
 
+#
 # Build and package an aarch64 binary
+#
 swift build --package-path "$PKGPATH" --swift-sdk aarch64-swift-linux-musl
-file "$PKGPATH/.build/aarch64-swift-linux-musl/debug/hello"
-IMGREF=$(swift run containertool --repository localhost:5000/elf_test "$PKGPATH/.build/aarch64-swift-linux-musl/debug/hello" --from scratch)
-docker pull "$IMGREF"
-docker inspect "$IMGREF" --format "{{.Architecture}}" | grep arm64
+FILETYPE=$(file "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello")
+log "Executable type: $FILETYPE"
 
-echo aarch64 detection: PASSED
+IMGREF=$(swift run containertool --repository localhost:5000/elf_test "$PKGPATH/.build/aarch64-swift-linux-musl/debug/hello" --from scratch)
+$RUNTIME pull "$IMGREF"
+IMGARCH=$($RUNTIME inspect "$IMGREF" --format "{{.Architecture}}")
+if [ "$IMGARCH" = "arm64" ] ; then
+  log "aarch64 detection: PASSED"
+else
+  fatal "aarch64 detection: FAILED - image architecture was $IMGARCH; expected arm64"
+fi

scripts/test-plugin-output-streaming.sh

@@ -1,8 +1,21 @@
 #!/usr/bin/env bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftContainerPlugin open source project
+##
+## Copyright (c) 2025 Apple Inc. and the SwiftContainerPlugin project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftContainerPlugin project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
 
 # Test that error output streamed from containertool is printed correctly by the plugin. 
 
-set -exo pipefail
+set -euo pipefail
 
 log() { printf -- "** %s\n" "$*" >&2; }
 error() { printf -- "** ERROR: %s\n" "$*" >&2; }
@@ -16,23 +29,27 @@ cleanup() {
 }
 trap cleanup EXIT
 
+# Create a test project which depends on this checkout of the plugin repository
+REPO_ROOT=$(git rev-parse --show-toplevel)
 swift package --package-path "$PKGPATH" init --type executable --name hello
 cat >> "$PKGPATH/Package.swift" <<EOF
 package.dependencies += [
-    .package(path: "$PWD"),
+    .package(path: "$REPO_ROOT"),
 ]
 EOF
+cat "$PKGPATH/Package.swift"
 
 # Run the plugin, forgetting a mandatory argument.   Verify that the output is not corrupted.
 # The `swift package` command will return a nonzero exit code.   This is expected, so disable pipefail.
 set +o pipefail
 swift package --package-path "$PKGPATH" --allow-network-connections all build-container-image 2>&1 | tee "$PKGPATH/output"
 set -o pipefail
 
+# This checks that the output lines are not broken, but not that they appear in the correct order
 grep -F -x -e "error: Missing expected argument '--repository <repository>'" \
            -e "error: Help:  --repository <repository>  Repository path" \
            -e "error: Usage: containertool [<options>] --repository <repository> <executable>" \
            -e "error:   See 'containertool --help' for more information." "$PKGPATH/output"
 
-echo Plugin error output: PASSED
+log Plugin error output: PASSED