tests: add basic test to check snap-gpio-helper binary is installed

Signed-off-by: Zeyad Gouda <[email protected]>

tests/main/snap-gpio-helper/task.yaml

@@ -0,0 +1,24 @@
+summary: Check that snap-helper-helper exists
+
+details: |
+  The test verifies that snap-gpio-helper exists
+
+systems: [ubuntu-*]
+
+execute: |
+    libexecdir=$(os.paths libexec-dir)
+    if tests.info is-snapd-from-archive; then
+        libexecdir="/snap/snapd/current$libexecdir"
+    fi
+
+    if [ ! -f "$libexecdir/snapd/snap-gpio-helper" ]; then
+      exit 1
+    fi
+
+    # Verify that snap-gpio-helper skeleton re-execs
+    echo "Ensure snap-gpio-helper re-execs"
+    set +e
+    SNAPD_DEBUG=1 "$libexecdir/snapd/snap-gpio-helper" 2>&1 | MATCH "DEBUG: restarting into"
+    set -e
+
+    # TODO: add more checks