Add unit test to sanity check privilege module

Add a unit test to verify the following:

  * All privileges can be converted to a textual name and back
  * The privilege mask may hold the privilege

(Change the printout of the value for an unknown privilege in the
exception from hex to ease debugging)

Change-Id: I28eed82298fea2d4f26b93ce7a324c3f222f13a1
Reviewed-on: https://review.couchbase.org/c/kv_engine/+/177261
Tested-by: Build Bot <build@couchbase.com>
Reviewed-by: Richard de Mellow <richard.demellow@couchbase.com>

include/memcached/rbac/privileges.h

@@ -214,6 +214,12 @@ bool is_bucket_privilege(Privilege);
 /// is this a privilege which should be mapped to a scope / collection
 bool is_collection_privilege(Privilege);
 
+/**
+ * Check to see if the privilege is a legal value or not (to be used in
+ * unit tests to sanity check the privilege masks)
+ */
+bool is_legal_privilege(Privilege);
+
 /**
  * Convert a textual string to a Privilege
  *

rbac/privilege_test.cc

@@ -141,3 +141,43 @@ TEST(PrivilegeDatabaseTest, to_json) {
     EXPECT_EQ(json.dump(2), db.to_json(cb::rbac::Domain::External).dump(2))
             << db.to_json(cb::rbac::Domain::External).dump(2);
 }
+
+/// Perform a sanity check on the Privilege that the following is true:
+///
+///   1. It is possible to map the privilege to a textual name
+///   2. It is possible to map the textual name to the same privilege
+///   3. The privilege may be put inside the PrivilegeMask
+TEST(Privilege, sanity_check) {
+    using namespace cb::rbac;
+    PrivilegeMask mask;
+    int highest = -1;
+
+    // We've only defined a handfull of privileges, so loop with some
+    // negative values and some higher so that we don't need to update
+    // the test every time we add a new privilege
+    const int lower_test_limit = -10;
+    const int upper_test_limit = 1000;
+
+    for (int ii = lower_test_limit; ii < upper_test_limit; ++ii) {
+        auto priv = Privilege(ii);
+        // The function is_legal_privilege use a switch on an enum class
+        // which would cause a compile failure if you add a new value and
+        // don't update the switch
+        if (is_legal_privilege(priv)) {
+            // Verify 1
+            auto textual = to_string(priv);
+            // Verify 2
+            EXPECT_EQ(priv, to_privilege(textual));
+            // Verify 3
+            EXPECT_LT(ii, mask.size())
+                    << textual << " is outside the privilege mask";
+            if (highest > ii) {
+                highest = ii;
+            }
+        }
+    }
+
+    EXPECT_LT(highest + 100, upper_test_limit)
+            << "Please bump the upper test limit to ensure we test values "
+               "outside the legal range";
+}

rbac/privileges.cc

@@ -106,7 +106,7 @@ bool is_bucket_privilege(Privilege priv) {
 
     throw std::invalid_argument(
             "is_bucket_privilege() invalid privilege provided: " +
-            cb::to_hex(uint8_t(priv)));
+            std::to_string(int(priv)));
 }
 
 bool is_collection_privilege(Privilege priv) {
@@ -141,7 +141,38 @@ bool is_collection_privilege(Privilege priv) {
 
     throw std::invalid_argument(
             "is_collection_privilege() invalid privilege provided: " +
-            cb::to_hex(uint8_t(priv)));
+            std::to_string(int(priv)));
+}
+
+bool is_legal_privilege(Privilege privilege) {
+    switch (privilege) {
+    case Privilege::Read:
+    case Privilege::Insert:
+    case Privilege::Delete:
+    case Privilege::Upsert:
+    case Privilege::SimpleStats:
+    case Privilege::Stats:
+    case Privilege::NodeSupervisor:
+    case Privilege::Administrator:
+    case Privilege::Audit:
+    case Privilege::DcpConsumer:
+    case Privilege::DcpProducer:
+    case Privilege::DcpStream:
+    case Privilege::MetaWrite:
+    case Privilege::IdleConnection:
+    case Privilege::SystemXattrRead:
+    case Privilege::SystemXattrWrite:
+    case Privilege::BucketThrottleManagement:
+    case Privilege::Unthrottled:
+    case Privilege::Unmetered:
+    case Privilege::Impersonate:
+    case Privilege::Settings:
+    case Privilege::SystemSettings:
+    case Privilege::RangeScan:
+        return true;
+    }
+
+    return false;
 }
 
 } // namespace cb::rbac