Verify the macOS package can load basic pages.

etc/ci/macos_package_smoketest.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+# If we somehow ended up in an unclean state previously, attempt
+# to set up a clean environment for testing.
+hdiutil detach /Volumes/Servo >/dev/null 2>&1 || true;
+
+# Mount the package that will be tested.
+hdiutil attach ${1}
+pushd /Volumes/Servo/Servo.app/Contents/MacOS
+ls -l
+
+# Load a page that closes immediately after loading.
+c='data:text/html,<script>onload=()=>{console.log("success");close()}</script>'
+./servo --headless ${c} | tee /tmp/out
+grep 'success' /tmp/out
+
+# Clean up.
+popd
+hdiutil detach /Volumes/Servo

etc/taskcluster/decision_task.py

@@ -277,6 +277,7 @@ def macos_unit():
             ./mach build --dev --verbose
             ./mach test-unit
             ./mach package --dev
+            ./etc/ci/macos_package_smoketest.sh target/debug/servo-tech-demo.dmg
             ./etc/ci/lockfile_changed.sh
         """)
         .find_or_create("macos_unit." + CONFIG.tree_hash())
@@ -451,6 +452,7 @@ def macos_nightly():
         .with_script(
             "./mach build --release",
             "./mach package --release",
+            "./etc/ci/macos_package_smoketest.sh target/release/servo-tech-demo.dmg"
             "./mach upload-nightly mac --secret-from-taskcluster",
         )
         .with_artifacts("repo/target/release/servo-tech-demo.dmg")