add tcl test for cluster slots

tests/cluster/tests/15-cluster-slots.tcl

@@ -0,0 +1,44 @@
+source "../tests/includes/init-tests.tcl"
+
+proc cluster_allocate_mixedSlots {n} {
+    set slot 16383
+    while {$slot >= 0} {
+        set node [expr {$slot % $n}]
+        lappend slots_$node $slot
+        incr slot -1
+    }
+    for {set j 0} {$j < $n} {incr j} {
+        R $j cluster addslots {*}[set slots_${j}]
+    }
+}
+
+proc create_cluster_with_mixedSlot {masters slaves} {
+    cluster_allocate_mixedSlots $masters
+    if {$slaves} {
+        cluster_allocate_slaves $masters $slaves
+    }
+    assert_cluster_state ok
+}
+
+test "Create a 5 nodes cluster" {
+    create_cluster_with_mixedSlot 5 15
+}
+
+test "Cluster is up" {
+    assert_cluster_state ok
+}
+
+test "Cluster is writable" {
+    cluster_write_test 0
+}
+
+test "Instance #5 is a slave" {
+    assert {[RI 5 role] eq {slave}}
+}
+
+test "client do not break when cluster slot" {
+    R 0 config set client-output-buffer-limit "normal 33554432 16777216 60"
+    if { [catch {R 0 cluster slots}] } {
+        fail "output overflow when cluster slots"
+    }
+}