tests: migrate ops test to bats

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

tests/ops/mounts/valid/tmpfs/main.cue

@@ -0,0 +1,34 @@
+package testing
+
+test: {
+	string
+
+	#up: [
+		{
+			do: "load"
+			from: [{do: "fetch-container", ref: "alpine"}]
+		},
+		{
+			do: "exec"
+			args: ["sh", "-c", """
+				echo ok > /out
+				echo ok > /tmpdir/out
+				"""]
+			dir: "/"
+			mount: "/tmpdir": "tmpfs"
+		},
+		{
+			do: "exec"
+			args: ["sh", "-c", """
+				[ -f /out ] || exit 1
+				# content of /cache/tmp must not exist in this layer
+				[ ! -f /tmpdir/out ] || exit 1
+				"""]
+		},
+		{
+			do:     "export"
+			source: "/out"
+			format: "string"
+		},
+	]
+}