diff --git a/src/proto_alpha/lib_protocol/test/delegation.ml b/src/proto_alpha/lib_protocol/test/delegation.ml
new file mode 100644
index 000000000..44a1e4eee
--- /dev/null
+++ b/src/proto_alpha/lib_protocol/test/delegation.ml
@@ -0,0 +1,996 @@
+(**************************************************************************)
+(*                                                                        *)
+(*    Copyright (c) 2014 - 2018.                                          *)
+(*    Dynamic Ledger Solutions, Inc. <contact@tezos.com>                  *)
+(*                                                                        *)
+(*    All rights reserved. No warranty, explicit or implicit, provided.   *)
+(*                                                                        *)
+(**************************************************************************)
+
+open Proto_alpha
+open Alpha_context
+open Test_tez
+
+(**************************************************************************)
+(* bootstrap contracts *)
+(**************************************************************************)
+(* Bootstrap contracts are heavily used in other tests. It is helpful
+   to test some properties of these contracts, so we can correctly
+   interpret the other tests that use them. *)
+
+let expect_error err = function
+  | err0 :: _ when err = err0 -> return ()
+  | _ -> failwith "Unexpected successful result"
+
+let expect_alpha_error err =
+  expect_error (Alpha_environment.Ecoproto_error err)
+
+let expect_non_delegatable_contract = function
+  | Alpha_environment.Ecoproto_error (Delegate_storage.Non_delegatable_contract _) :: _ ->
+      return ()
+  | _ ->
+      failwith "Contract is not delegatable and operation should fail."
+
+let expect_no_deletion_pkh pkh = function
+  | Alpha_environment.Ecoproto_error (Delegate_storage.No_deletion pkh0) :: _ when pkh0 = pkh ->
+      return ()
+  | _ ->
+      failwith "Delegate can not be deleted and operation should fail."
+
+(** bootstrap contracts delegate to themselves *)
+let bootstrap_manager_is_bootstrap_delegate () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  let bootstrap0 = List.hd bootstrap_contracts in
+  Context.Contract.delegate (B b) bootstrap0 >>=? fun delegate0 ->
+  Context.Contract.manager (B b) bootstrap0 >>=? fun manager0 ->
+  Assert.equal_pkh ~loc:__LOC__ delegate0 manager0.pkh
+
+(** bootstrap contracts cannot change their delegate *)
+let bootstrap_delegate_cannot_change ~fee () =
+  Context.init 2 >>=? fun (b, bootstrap_contracts) ->
+  let bootstrap0 = List.nth bootstrap_contracts 0 in
+  let bootstrap1 = List.nth bootstrap_contracts 1 in
+  Incremental.begin_construction b >>=? fun i ->
+  Context.Contract.manager (I i) bootstrap1 >>=? fun manager1 ->
+  Context.Contract.balance (I i) bootstrap0 >>=? fun balance0 ->
+  Context.Contract.delegate (I i) bootstrap0 >>=? fun delegate0 ->
+  Op.delegation ~fee (I i) bootstrap0 (Some manager1.pkh) >>=? fun set_delegate ->
+  if fee > balance0 then
+    Incremental.add_operation i set_delegate >>= fun err ->
+    Assert.proto_error ~loc:__LOC__ err (function
+        | Contract_storage.Balance_too_low _ -> true
+        | _ -> false)
+  else
+    Incremental.add_operation
+      ~expect_failure:expect_non_delegatable_contract i set_delegate >>=? fun i ->
+    Incremental.finalize_block i >>=? fun b ->
+    (* bootstrap0 still has same delegate *)
+    Context.Contract.delegate (B b) bootstrap0 >>=? fun delegate0_after ->
+    Assert.equal_pkh ~loc:__LOC__ delegate0 delegate0_after >>=? fun () ->
+    (* fee has been debited *)
+    Assert.balance_was_debited ~loc:__LOC__ (B b) bootstrap0 balance0 fee
+
+
+(** bootstrap contracts cannot delete their delegation *)
+let bootstrap_delegate_cannot_be_removed ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  let bootstrap = List.hd bootstrap_contracts in
+  Incremental.begin_construction b >>=? fun i ->
+  Context.Contract.balance (I i) bootstrap >>=? fun balance ->
+  Context.Contract.delegate (I i) bootstrap >>=? fun delegate ->
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  Op.delegation ~fee (I i) bootstrap None >>=? fun set_delegate ->
+  if fee > balance then
+    Incremental.add_operation i set_delegate >>= fun err ->
+    Assert.proto_error ~loc:__LOC__ err (function
+        | Contract_storage.Balance_too_low _ -> true
+        | _ -> false)
+  else
+    Incremental.add_operation
+      ~expect_failure:(expect_no_deletion_pkh manager.pkh) i set_delegate >>=? fun i ->
+    (* delegate has not changed *)
+    Context.Contract.delegate (I i) bootstrap >>=? fun delegate_after ->
+    Assert.equal_pkh ~loc:__LOC__ delegate delegate_after >>=? fun () ->
+    (* fee has been debited *)
+    Assert.balance_was_debited ~loc:__LOC__ (I i) bootstrap balance fee
+
+(** bootstrap keys are already registered as delegate keys *)
+let bootstrap_manager_already_registered_delegate ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  let pkh = manager.pkh in
+  let impl_contract = Contract.implicit_contract pkh in
+  Context.Contract.balance (I i) impl_contract >>=? fun balance ->
+  Op.delegation ~fee (I i) impl_contract (Some pkh) >>=? fun sec_reg ->
+  if fee > balance then
+    begin
+      Incremental.add_operation i sec_reg >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    begin
+      Incremental.add_operation ~expect_failure:(function
+          |  Alpha_environment.Ecoproto_error Delegate_storage.Active_delegate :: _ ->
+              return ()
+          | _ ->
+              failwith "Delegate is already active and operation should fail.")
+        i sec_reg >>=? fun i ->
+      (* fee has been debited *)
+      Assert.balance_was_debited ~loc:__LOC__ (I i) impl_contract balance fee
+    end
+
+(** bootstrap manager can be set as delegate of an originated contract
+    (through origination operation) *)
+let delegate_to_bootstrap_by_origination ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  Context.Contract.balance (I i) bootstrap >>=? fun balance ->
+  (* originate a contract with bootstrap's manager as delegate *)
+  Op.origination ~fee ~credit:Tez.zero ~delegate:manager.pkh (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Context.get_constants (I i) >>=? fun { parametric = { origination_burn ; _ }} -> (* 0.257tz *)
+  Lwt.return (Tez.(+?) fee origination_burn) >>=? fun total_fee ->
+  if fee > balance then
+    begin
+      Incremental.add_operation i op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else if total_fee > balance && balance >= fee then
+    (* origination did not proceed; fee has been debited *)
+    begin
+      Incremental.add_operation i ~expect_failure:(function
+          |  Alpha_environment.Ecoproto_error Contract.Balance_too_low _ :: _ ->
+              return ()
+          | _ ->
+              failwith "Not enough balance for origination burn: operation should fail.")
+        op >>=? fun i ->
+      (* fee was taken *)
+      Assert.balance_was_debited ~loc:__LOC__ (I i) bootstrap balance fee >>=? fun () ->
+      (* originated contract has not been created *)
+      Context.Contract.balance (I i) orig_contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+  else
+    (* bootstrap is delegate, fee + origination burn have been debited *)
+    begin
+      Incremental.add_operation i op >>=? fun i ->
+      Context.Contract.delegate (I i) orig_contract >>=? fun delegate ->
+      Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh >>=? fun () ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) bootstrap balance total_fee
+    end
+
+(** bootstrap manager can be set as delegate of an originated contract
+    without initial delegate (through delegation operation) *)
+let delegate_to_bootstrap_by_delegation ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  (* originate a contract with no delegate *)
+  Op.origination ~fee:Tez.zero (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.balance (I i) orig_contract >>=? fun orig_balance ->
+  (* Format.printf "\nBalance of originated contract: %a\n%!" Tez.pp orig_balance; *)
+  (* delegate to bootstrap *)
+  Op.delegation ~fee (I i) orig_contract (Some manager.pkh) >>=? fun deleg_op ->
+  if fee > orig_balance then
+    begin
+      Incremental.add_operation i deleg_op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    (* manager is delegate, fee is debited *)
+    begin
+      Incremental.add_operation i deleg_op >>=? fun i ->
+      Context.Contract.delegate (I i) orig_contract >>=? fun delegate ->
+      Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh >>=? fun () ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) orig_contract orig_balance fee
+    end
+
+(** bootstrap manager can be set as delegate of an originated contract
+    with initial delegate (through delegation operation) *)
+let delegate_to_bootstrap_by_delegation_switch ~fee () =
+  Context.init 2 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap0 = List.hd bootstrap_contracts in
+  Context.Contract.manager (I i) bootstrap0 >>=? fun manager0 ->
+  let bootstrap1 = List.nth bootstrap_contracts 1 in
+  Context.Contract.manager (I i) bootstrap1 >>=? fun manager1 ->
+  (* originate a contract with bootstrap1's manager as delegate *)
+  Op.origination ~fee:Tez.zero ~credit:Tez.one ~delegate:manager1.pkh (I i) bootstrap0 >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.balance (I i) orig_contract >>=? fun orig_balance ->
+  Context.Contract.delegate (I i) orig_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate manager1.pkh >>=? fun _ ->
+  (* switch delegate to bootstrap0 *)
+  Op.delegation ~fee (I i) orig_contract (Some manager0.pkh) >>=? fun switch_deleg ->
+  if fee > orig_balance then
+    begin
+      Incremental.add_operation i switch_deleg >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    (* manager0 is delegate, fee is debited *)
+    begin
+      Incremental.add_operation i switch_deleg >>=? fun i ->
+      Context.Contract.delegate (I i) orig_contract >>=? fun delegate ->
+      Assert.equal_pkh ~loc:__LOC__ delegate manager0.pkh >>=? fun () ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) orig_contract orig_balance fee
+    end
+
+let tests_bootstrap_contracts = [
+  Test.tztest "bootstrap contracts delegate to themselves" `Quick bootstrap_manager_is_bootstrap_delegate ;
+  Test.tztest "bootstrap contracts cannot change their delegate (small fee)" `Quick (bootstrap_delegate_cannot_change ~fee:Tez.one_mutez) ;
+  Test.tztest "bootstrap contracts cannot change their delegate (max fee)" `Quick (bootstrap_delegate_cannot_change ~fee:Tez.max_tez) ;
+  Test.tztest "bootstrap contracts cannot delete their delegation (small fee)" `Quick (bootstrap_delegate_cannot_be_removed ~fee:Tez.one_mutez) ;
+  Test.tztest "bootstrap contracts cannot delete their delegation (max fee)" `Quick (bootstrap_delegate_cannot_be_removed ~fee:Tez.max_tez) ;
+  Test.tztest "bootstrap keys are already registered as delegate keys (small fee)" `Quick (bootstrap_manager_already_registered_delegate ~fee:Tez.one_mutez) ;
+  Test.tztest "bootstrap keys are already registered as delegate keys (max fee)" `Quick (bootstrap_manager_already_registered_delegate ~fee:Tez.max_tez) ;
+  Test.tztest "bootstrap manager can be delegate (init origination, small fee)" `Quick (delegate_to_bootstrap_by_origination ~fee:Tez.one_mutez) ;
+  (* balance enough for fee but not for fee + origination burn *)
+  Test.tztest "bootstrap manager can be delegate (init origination, edge case)" `Quick (delegate_to_bootstrap_by_origination ~fee:(Tez.of_mutez_exn 3_999_999_750_000L)) ;
+  (* fee bigger than bootstrap's initial balance*)
+  Test.tztest "bootstrap manager can be delegate (init origination, large fee)" `Quick (delegate_to_bootstrap_by_origination ~fee:(Tez.of_int 10_000_000)) ;
+  Test.tztest "bootstrap manager can be delegate (init delegation, small fee)" `Quick (delegate_to_bootstrap_by_delegation ~fee:Tez.one_mutez) ;
+  Test.tztest "bootstrap manager can be delegate (init delegation, max fee)" `Quick (delegate_to_bootstrap_by_delegation ~fee:Tez.max_tez) ;
+  Test.tztest "bootstrap manager can be delegate (switch delegation, small fee)" `Quick (delegate_to_bootstrap_by_delegation_switch ~fee:Tez.one_mutez) ;
+  Test.tztest "bootstrap manager can be delegate (switch delegation, max fee)" `Quick (delegate_to_bootstrap_by_delegation_switch ~fee:Tez.max_tez) ;
+]
+
+(**************************************************************************)
+(* delegate registration *)
+(**************************************************************************)
+(* A delegate is a pkh. Delegates must be registered. Registration is
+   done via the self-delegation of the implicit contract corresponding
+   to the pkh. The implicit contract must be credited when the
+   self-delegation is done. Furthermore, trying to register an already
+   registered key raises an error.
+
+   In this series of tests, we verify that
+   1- unregistered delegate keys cannot be delegated to,
+   2- registered keys can be delegated to,
+   3- registering an already registered key raises an error.
+
+
+   We consider three scenarios for setting a delegate:
+   - through origination,
+   - through delegation when the originated contract has no delegate yet,
+   - through delegation when the originated contract already has a delegate.
+
+   We also test that emptying the implicit contract linked to a
+   registered delegate key does not unregister the delegate key.
+*)
+
+(*
+   Valid registration
+
+   Unregistered key:
+   - contract not credited and no self-delegation
+   - contract credited but no self-delegation
+   - contract not credited and self-delegation
+
+Not credited:
+- no credit operation
+- credit operation of 1μꜩ and then debit operation of 1μꜩ
+
+*)
+
+(** A- unregistered delegate keys cannot be used for delegation *)
+
+(* Two main series of tests: without self-delegation, and with a failed attempt at self-delegation
+   1- no self-delegation
+     a- no credit
+        - no token transfer
+        - credit of 1μꜩ and then debit of 1μꜩ
+     b- with credit of 1μꜩ.
+   For every scenario, we try three different ways of delegating:
+   - through origination (init origination)
+   - through delegation when no delegate was assigned at origination (init delegation)
+   - through delegation when a delegate was assigned at origination (switch delegation).
+
+   2- Self-delegation fails if the contract has no credit. We try the
+   two possibilities of 1a for non-credited contracts.
+*)
+
+let expect_unregistered_key pkh = function
+  | Alpha_environment.Ecoproto_error Roll_storage.Unregistered_delegate pkh0 :: _
+    when pkh = pkh0 -> return ()
+  | _ -> failwith "Delegate key is not registered: operation should fail."
+
+(* A1: no self-delegation *)
+(* no token transfer, no self-delegation *)
+let unregistered_delegate_key_init_origination ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  (* origination with delegate argument *)
+  Op.origination ~fee ~delegate:unregistered_pkh (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Context.get_constants (I i) >>=? fun { parametric = { origination_burn ; _ }} ->
+  Lwt.return (Tez.(+?) fee origination_burn) >>=? fun _total_fee -> (* FIXME unused variable *)
+  Context.Contract.balance (I i) bootstrap >>=? fun balance ->
+  if fee > balance then
+    begin
+      Incremental.add_operation i op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    (* origination did not proceed; fee has been debited *)
+    begin
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) bootstrap balance fee >>=? fun () ->
+      (* originated contract has not been created *)
+      Context.Contract.balance (I i) orig_contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+
+let unregistered_delegate_key_init_delegation ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  Context.Contract.balance (I i) bootstrap >>=? fun _balance -> (* FIXME unused variable *)
+  (* origination without delegate argument *)
+  let credit = Tez.of_int 10 in
+  Op.origination (I i) bootstrap ~credit  >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Op.delegation ~fee (I i) orig_contract (Some unregistered_pkh) >>=? fun delegate_op ->
+  if fee > credit then
+    begin
+      Incremental.add_operation i delegate_op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    (* fee has been debited; no delegate *)
+    begin
+      Incremental.add_operation i
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        delegate_op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) orig_contract credit fee >>=? fun () ->
+      (* originated contract has no delegate *)
+      Context.Contract.delegate (I i) orig_contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+
+let unregistered_delegate_key_switch_delegation ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  (* origination with delegate setting *)
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  let credit = Tez.of_int 10 in
+  Op.origination (I i) ~delegate:manager.pkh bootstrap ~credit >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.delegate (I i) orig_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh >>=? fun _ ->
+  (* switch delegate through delegation *)
+  Op.delegation ~fee (I i) orig_contract (Some unregistered_pkh) >>=? fun delegate_op ->
+  if fee > credit then
+    begin
+      Incremental.add_operation i delegate_op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    (* fee has been debited; no delegate *)
+    begin
+      Incremental.add_operation i
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        delegate_op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) orig_contract credit fee >>=? fun () ->
+      (* originated contract's delegate has not changed *)
+      Context.Contract.delegate (I i) orig_contract >>=? fun delegate ->
+      Assert.not_equal_pkh ~loc:__LOC__ delegate unregistered_pkh >>=? fun () ->
+      Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh
+    end
+
+(* credit of some amount, no self-delegation *)
+let unregistered_delegate_key_init_origination_credit ~fee ~amount () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* credit + check balance *)
+  Op.transaction ~fee:Tez.zero (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* origination with delegate argument *)
+  Context.Contract.balance (I i) bootstrap >>=? fun balance ->
+  Op.origination ~fee ~delegate:unregistered_pkh (I i) bootstrap >>=? fun (op, orig_contract) ->
+  if fee > balance then
+    begin
+      Incremental.add_operation i op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else (* origination not done, fee taken *)
+    begin
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) bootstrap balance fee >>=? fun () ->
+      Context.Contract.balance (I i) orig_contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+
+let unregistered_delegate_key_init_delegation_credit ~fee ~amount () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* credit + check balance *)
+  Op.transaction ~fee:Tez.zero (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* origination without delegate argument *)
+  let credit = Tez.of_int 10 in
+  Op.origination ~fee:Tez.zero ~credit (I i) bootstrap >>=? fun (op, contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Op.delegation ~fee (I i) contract (Some unregistered_pkh) >>=? fun delegate_op ->
+  if fee > credit then
+    Incremental.add_operation i delegate_op >>= fun err ->
+    Assert.proto_error ~loc:__LOC__ err (function
+        | Contract_storage.Balance_too_low _ -> true
+        | _ -> false)
+  else
+    begin
+      (* fee has been taken, no delegate for contract *)
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i delegate_op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) contract credit fee >>=? fun () ->
+      Context.Contract.delegate (I i) contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+
+let unregistered_delegate_key_switch_delegation_credit ~fee ~amount () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* credit + check balance *)
+  Op.transaction ~fee:Tez.zero (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* origination without delegate setting *)
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  let credit = Tez.of_int 10 in
+  Op.origination (I i) ~fee:Tez.zero ~credit ~delegate:manager.pkh bootstrap >>=? fun (op, contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.delegate (I i) contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh >>=? fun _ ->
+  (* switch delegate through delegation *)
+  Op.delegation ~fee (I i) contract (Some unregistered_pkh) >>=? fun delegate_op ->
+  if fee > credit then
+    Incremental.add_operation i delegate_op >>= fun err ->
+    Assert.proto_error ~loc:__LOC__ err (function
+        | Contract_storage.Balance_too_low _ -> true
+        | _ -> false)
+  else
+    begin
+      (* fee has been taken, delegate for contract has not changed *)
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i delegate_op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) contract credit fee >>=? fun () ->
+      Context.Contract.delegate (I i) contract >>=? fun delegate ->
+      Assert.not_equal_pkh ~loc:__LOC__ delegate unregistered_pkh >>=? fun () ->
+      Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh
+    end
+
+(* a credit of some amount followed by a debit of the same amount, no self-delegation *)
+let unregistered_delegate_key_init_origination_credit_debit ~fee ~amount () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* credit + check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* debit + check balance *)
+  Op.transaction (I i) impl_contract bootstrap amount >>=? fun debit_contract ->
+  Incremental.add_operation i debit_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* origination with delegate argument *)
+  Context.Contract.balance (I i) bootstrap >>=? fun balance ->
+  Op.origination ~fee ~delegate:unregistered_pkh (I i) bootstrap >>=? fun (op, orig_contract) ->
+  if fee > balance then
+    begin
+      Incremental.add_operation i op  >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else (* fee taken, origination not processed *)
+    begin
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) bootstrap balance fee >>=? fun () ->
+      Context.Contract.balance (I i) orig_contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+
+let unregistered_delegate_key_init_delegation_credit_debit ~amount ~fee () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* credit + check balance *)
+  Op.transaction ~fee:Tez.zero (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* debit + check balance *)
+  Op.transaction ~fee:Tez.zero (I i) impl_contract bootstrap amount >>=? fun debit_contract ->
+  Incremental.add_operation i debit_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* origination without delegate argument *)
+  let credit = Tez.of_int 10 in
+  Op.origination ~fee:Tez.zero (I i) ~credit bootstrap >>=? fun (op, contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  (* set a delegate with delegation operation *)
+  Op.delegation ~fee (I i) contract (Some unregistered_pkh) >>=? fun delegate_op ->
+  if fee > credit then
+    begin
+      Incremental.add_operation i delegate_op >>= fun err ->
+      Assert.proto_error ~loc:__LOC__ err (function
+          | Contract_storage.Balance_too_low _ -> true
+          | _ -> false)
+    end
+  else
+    begin
+      (* fee has been taken, no delegate for contract *)
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i delegate_op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) contract credit fee >>=? fun () ->
+      Context.Contract.delegate (I i) contract >>= fun err ->
+      Assert.error ~loc:__LOC__ err (function
+          | RPC_context.Not_found _ -> true
+          | _ -> false)
+    end
+
+let unregistered_delegate_key_switch_delegation_credit_debit ~fee ~amount () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let unregistered_account = Account.new_account () in
+  let unregistered_pkh = Account.(unregistered_account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* credit + check balance *)
+  Op.transaction ~fee:Tez.zero (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* debit + check balance *)
+  Op.transaction (I i) impl_contract bootstrap amount >>=? fun debit_contract ->
+  Incremental.add_operation i debit_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* origination with delegate setting *)
+  Context.Contract.manager (I i) bootstrap >>=? fun manager ->
+  let credit = Tez.of_int 10 in
+  Op.origination (I i) ~fee:Tez.zero ~credit ~delegate:manager.pkh bootstrap >>=? fun (op, contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.delegate (I i) contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh >>=? fun _ ->
+  (* switch delegate through delegation *)
+  Op.delegation (I i) ~fee contract (Some unregistered_pkh) >>=? fun delegate_op ->
+  if fee > credit then
+    Incremental.add_operation i delegate_op >>= fun err ->
+    Assert.proto_error ~loc:__LOC__ err (function
+        | Contract_storage.Balance_too_low _ -> true
+        | _ -> false)
+  else
+    begin
+      (* fee has been taken, delegate for contract has not changed *)
+      Incremental.add_operation
+        ~expect_failure:(expect_unregistered_key unregistered_pkh)
+        i delegate_op >>=? fun i ->
+      Assert.balance_was_debited ~loc:__LOC__ (I i) contract credit fee >>=? fun () ->
+      Context.Contract.delegate (I i) contract >>=? fun delegate ->
+      Assert.not_equal_pkh ~loc:__LOC__ delegate unregistered_pkh >>=? fun () ->
+      Assert.equal_pkh ~loc:__LOC__ delegate manager.pkh
+    end
+
+(* A2- self-delegation to an empty contract fails *)
+let failed_self_delegation_no_transaction () =
+  Context.init 1 >>=? fun (b, _) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let account = Account.new_account () in
+  let unregistered_pkh = Account.(account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (* check balance *)
+  Context.Contract.balance (I i) impl_contract >>=? fun balance ->
+  Assert.equal_tez ~loc:__LOC__ Tez.zero balance >>=? fun _ ->
+  (* self delegation fails *)
+  Op.delegation (I i) impl_contract (Some unregistered_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>= fun err ->
+  Assert.proto_error ~loc:__LOC__ err (function
+      | Contract_storage.Empty_implicit_contract pkh ->
+          if pkh = unregistered_pkh then true else false
+      | _ -> false)
+
+let failed_self_delegation_emptied_implicit_contract amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let account = Account.new_account () in
+  let unregistered_pkh = Account.(account.pkh) in
+  let impl_contract = Contract.implicit_contract unregistered_pkh in
+  (*  credit implicit contract and check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* empty implicit contract and check balance *)
+  Op.transaction (I i) impl_contract bootstrap amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* self delegation fails *)
+  Op.delegation (I i) impl_contract (Some unregistered_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>= fun err ->
+  Assert.proto_error ~loc:__LOC__ err (function
+      | Contract_storage.Empty_implicit_contract pkh ->
+          if pkh = unregistered_pkh then true else false
+      | _ -> false)
+
+(** B- valid registration:
+    - credit implicit contract with some ꜩ + verification of balance
+    - self delegation + verification
+    - empty contract + verification of balance + verification of not being erased / self-delegation
+    - originate contract w implicit contract as delegate + verification of delegation *)
+let valid_delegate_registration_init_origination_credit amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let delegate_account = Account.new_account () in
+  let delegate_pkh = Account.(delegate_account.pkh) in
+  let impl_contract = Contract.implicit_contract delegate_pkh in
+  (* credit > 0ꜩ + check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* self delegation + verification *)
+  Op.delegation (I i) impl_contract (Some delegate_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate delegate_pkh >>=? fun _ ->
+  (* originating a contract with the newly registered delegate account as delegate *)
+  Op.origination ~delegate:delegate_account.pkh (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate delegate_pkh
+
+let valid_delegate_registration_init_delegation_credit amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let delegate_account = Account.new_account () in
+  let delegate_pkh = Account.(delegate_account.pkh) in
+  let impl_contract = Contract.implicit_contract delegate_pkh in
+  (* credit > 0ꜩ + check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* self delegation + verification *)
+  Op.delegation (I i) impl_contract (Some delegate_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate delegate_pkh >>=? fun _ ->
+  (* originating a contract with no delegate *)
+  Op.origination (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  (* check no delegate for orig contract *)
+  Context.Contract.delegate (I i) orig_contract >>= fun err ->
+  Assert.error ~loc:__LOC__ err (function
+      | RPC_context.Not_found _ -> true
+      | _ -> false) >>=? fun _ ->
+  (* delegation to the newly registered key *)
+  Op.delegation (I i) orig_contract (Some delegate_account.pkh) >>=? fun delegation ->
+  Incremental.add_operation i delegation >>=? fun i ->
+  (* check delegation *)
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate delegate_pkh
+
+let valid_delegate_registration_switch_delegation_credit amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let delegate_account = Account.new_account () in
+  let delegate_pkh = Account.(delegate_account.pkh) in
+  let impl_contract = Contract.implicit_contract delegate_pkh in
+  (* credit > 0ꜩ + check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* self delegation + verification *)
+  Op.delegation (I i) impl_contract (Some delegate_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate delegate_pkh >>=? fun _ ->
+  (* originating a contract with bootstrap's account as delegate *)
+  Context.Contract.manager (I i) bootstrap >>=? fun bootstrap_manager ->
+  Op.origination (I i) ~delegate:bootstrap_manager.pkh bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  (* test delegate of new contract is bootstrap *)
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate bootstrap_manager.pkh  >>=? fun _ ->
+  (* delegation with newly registered key *)
+  Op.delegation (I i) orig_contract (Some delegate_account.pkh) >>=? fun delegation ->
+  Incremental.add_operation i delegation >>=? fun i ->
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate delegate_pkh
+
+let valid_delegate_registration_init_origination_credit_debit amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let delegate_account = Account.new_account () in
+  let delegate_pkh = Account.(delegate_account.pkh) in
+  let impl_contract = Contract.implicit_contract delegate_pkh in
+  (* credit > 0ꜩ+ check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* self delegation + verification *)
+  Op.delegation (I i) impl_contract (Some delegate_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate_pkh delegate >>=? fun _ ->
+  (* empty implicit contracts are usually deleted but they are kept if
+     they were registered as delegates. we empty the contract in
+     order to verify this. *)
+  Op.transaction (I i) impl_contract bootstrap amount >>=? fun empty_contract ->
+  Incremental.add_operation i empty_contract >>=? fun i ->
+  (* impl_contract is empty *)
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* verify self-delegation after contract is emptied *)
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate_pkh delegate >>=? fun _ ->
+  (* originating a contract with the newly registered delegate account as delegate *)
+  Op.origination ~delegate:delegate_account.pkh (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate delegate_pkh
+
+let valid_delegate_registration_init_delegation_credit_debit amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let delegate_account = Account.new_account () in
+  let delegate_pkh = Account.(delegate_account.pkh) in
+  let impl_contract = Contract.implicit_contract delegate_pkh in
+  (* credit > 0ꜩ+ check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* self delegation + verification *)
+  Op.delegation (I i) impl_contract (Some delegate_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate_pkh delegate >>=? fun _ ->
+  (* empty implicit contracts are usually deleted but they are kept if
+     they were registered as delegates. we empty the contract in
+     order to verify this. *)
+  Op.transaction (I i) impl_contract bootstrap amount >>=? fun empty_contract ->
+  Incremental.add_operation i empty_contract >>=? fun i ->
+  (* impl_contract is empty *)
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* verify self-delegation after contract is emptied *)
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate_pkh delegate >>=? fun _ ->
+  (* originating a contract with no delegate *)
+  Op.origination (I i) bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  (* check no delegate for orig contract *)
+  Context.Contract.delegate (I i) orig_contract >>= fun err ->
+  Assert.error ~loc:__LOC__ err (function
+      | RPC_context.Not_found _ -> true
+      | _ -> false) >>=? fun _ ->
+  (* delegation to the newly registered key *)
+  Op.delegation (I i) orig_contract (Some delegate_account.pkh) >>=? fun delegation ->
+  Incremental.add_operation i delegation >>=? fun i ->
+  (* check delegation *)
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate delegate_pkh
+
+let valid_delegate_registration_switch_delegation_credit_debit amount () =
+  (* create an implicit contract *)
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let delegate_account = Account.new_account () in
+  let delegate_pkh = Account.(delegate_account.pkh) in
+  let impl_contract = Contract.implicit_contract delegate_pkh in
+  (* credit > 0ꜩ + check balance *)
+  Op.transaction (I i) bootstrap impl_contract amount >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract amount >>=? fun _ ->
+  (* self delegation + verification *)
+  Op.delegation (I i) impl_contract (Some delegate_pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  Context.Contract.delegate (I i) impl_contract >>=? fun delegate ->
+  Assert.equal_pkh ~loc:__LOC__ delegate_pkh delegate >>=? fun _ ->
+  (* empty implicit contracts are usually deleted but they are kept if
+     they were registered as delegates. we empty the contract in
+     order to verify this. *)
+  Op.transaction (I i) impl_contract bootstrap amount >>=? fun empty_contract ->
+  Incremental.add_operation i empty_contract >>=? fun i ->
+  (* impl_contract is empty *)
+  Assert.balance_is ~loc:__LOC__ (I i) impl_contract Tez.zero >>=? fun _ ->
+  (* originating a contract with bootstrap's account as delegate *)
+  Context.Contract.manager (I i) bootstrap >>=? fun bootstrap_manager ->
+  Op.origination (I i) ~delegate:bootstrap_manager.pkh bootstrap >>=? fun (op, orig_contract) ->
+  Incremental.add_operation i op >>=? fun i ->
+  (* test delegate of new contract is bootstrap *)
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate bootstrap_manager.pkh  >>=? fun _ ->
+  (* delegation with newly registered key *)
+  Op.delegation (I i) orig_contract (Some delegate_account.pkh) >>=? fun delegation ->
+  Incremental.add_operation i delegation >>=? fun i ->
+  Context.Contract.delegate (I i) orig_contract >>=? fun orig_delegate ->
+  Assert.equal_pkh ~loc:__LOC__ orig_delegate delegate_pkh
+
+(** C- a second self-delegation should raise an `Active_delegate` error *)
+(* with implicit contract with some credits *)
+let double_registration () =
+  Context.init 1 >>=? fun (b, bootstrap_contracts) ->
+  Incremental.begin_construction b >>=? fun i ->
+  let bootstrap = List.hd bootstrap_contracts in
+  let account = Account.new_account () in
+  let pkh = Account.(account.pkh) in
+  let impl_contract = Contract.implicit_contract pkh in
+  (* credit 1μꜩ+ check balance *)
+  Op.transaction (I i) bootstrap impl_contract (Tez.one_mutez) >>=? fun create_contract ->
+  Incremental.add_operation i create_contract >>=? fun i ->
+  (* return () *)
+  (* self-delegation *)
+  Op.delegation (I i) impl_contract (Some pkh) >>=? fun self_delegation ->
+  Incremental.add_operation i self_delegation >>=? fun i ->
+  (* second self-delegation *)
+  Op.delegation (I i) impl_contract (Some pkh) >>=? fun second_registration ->
+  Incremental.add_operation i second_registration >>= fun err ->
+  Assert.proto_error ~loc:__LOC__ err (function
+      | Delegate_storage.Active_delegate -> true
+      | _ -> false)
+
+let tests_delegate_registration =
+  [
+    (*** unregistered delegate key: no self-delegation ***)
+    (* no token transfer, no self-delegation *)
+    Test.tztest "unregistered delegate key (origination, small fee)"
+      `Quick (unregistered_delegate_key_init_origination ~fee:Tez.one_mutez);
+    Test.tztest "unregistered delegate key (origination, edge case fee)"
+      `Quick (unregistered_delegate_key_init_origination ~fee:(Tez.of_int 3_999_488));
+    Test.tztest "unregistered delegate key (origination, large fee)"
+      `Quick (unregistered_delegate_key_init_origination ~fee:(Tez.of_int 10_000_000));
+
+    Test.tztest "unregistered delegate key (init with delegation, small fee)"
+      `Quick (unregistered_delegate_key_init_delegation ~fee:Tez.one_mutez);
+    Test.tztest "unregistered delegate key (init with delegation, max fee)"
+      `Quick (unregistered_delegate_key_init_delegation ~fee:Tez.max_tez);
+
+    Test.tztest "unregistered delegate key (switch with delegation, small fee)"
+      `Quick (unregistered_delegate_key_switch_delegation ~fee:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key (switch with delegation, max fee)"
+      `Quick (unregistered_delegate_key_switch_delegation ~fee:Tez.max_tez) ;
+
+    (* credit/debit 1μꜩ, no self-delegation *)
+    Test.tztest "unregistered delegate key - credit/debit 1μꜩ (origination, small fee)"
+      `Quick (unregistered_delegate_key_init_origination_credit_debit ~fee:Tez.one_mutez ~amount:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit/debit 1μꜩ (origination, large fee)"
+      `Quick (unregistered_delegate_key_init_origination_credit_debit ~fee:Tez.max_tez ~amount:Tez.one_mutez) ;
+
+    Test.tztest "unregistered delegate key - credit/debit 1μꜩ (init with delegation, small fee)"
+      `Quick (unregistered_delegate_key_init_delegation_credit_debit ~amount:Tez.one_mutez ~fee:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit/debit 1μꜩ (init with delegation, large fee)"
+      `Quick (unregistered_delegate_key_init_delegation_credit_debit ~amount:Tez.one_mutez ~fee:Tez.max_tez) ;
+
+    Test.tztest "unregistered delegate key - credit/debit 1μꜩ (switch with delegation, small fee)"
+      `Quick (unregistered_delegate_key_switch_delegation_credit_debit ~amount:Tez.one_mutez ~fee:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit/debit 1μꜩ (switch with delegation, large fee)"
+      `Quick (unregistered_delegate_key_switch_delegation_credit_debit ~amount:Tez.one_mutez ~fee:Tez.max_tez) ;
+
+    (* credit 1μꜩ, no self-delegation *)
+    Test.tztest "unregistered delegate key - credit 1μꜩ (origination, small fee)"
+      `Quick (unregistered_delegate_key_init_origination_credit ~fee:Tez.one_mutez ~amount:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit 1μꜩ (origination, edge case fee)"
+      `Quick (unregistered_delegate_key_init_origination_credit ~fee:(Tez.of_int 3_999_488) ~amount:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit 1μꜩ (origination, large fee)"
+      `Quick (unregistered_delegate_key_init_origination_credit ~fee:(Tez.of_int 10_000_000) ~amount:Tez.one_mutez) ;
+
+    Test.tztest "unregistered delegate key - credit 1μꜩ (init with delegation, small fee)"
+      `Quick (unregistered_delegate_key_init_delegation_credit ~amount:Tez.one_mutez ~fee:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit 1μꜩ (init with delegation, large fee)"
+      `Quick (unregistered_delegate_key_init_delegation_credit ~amount:Tez.one_mutez ~fee:Tez.max_tez) ;
+
+    Test.tztest "unregistered delegate key - credit 1μꜩ (switch with delegation, small fee)"
+      `Quick (unregistered_delegate_key_switch_delegation_credit ~amount:Tez.one_mutez ~fee:Tez.one_mutez) ;
+    Test.tztest "unregistered delegate key - credit 1μꜩ (switch with delegation, large fee)"
+      `Quick (unregistered_delegate_key_switch_delegation_credit ~amount:Tez.one_mutez ~fee:Tez.max_tez) ;
+
+    (*** unregistered delegate key: failed self-delegation ***)
+    (* no token transfer, self-delegation *)
+    Test.tztest "failed self-delegation: no transaction" `Quick failed_self_delegation_no_transaction ;
+    (* credit 1μtz, debit 1μtz, self-delegation *)
+    Test.tztest "failed self-delegation: credit & debit 1μꜩ" `Quick (failed_self_delegation_emptied_implicit_contract Tez.one_mutez) ;
+
+    (*** valid registration ***)
+    (* valid registration: credit 1 μꜩ, self delegation *)
+    Test.tztest "valid delegate registration: credit 1μꜩ, self delegation (origination)"
+      `Quick (valid_delegate_registration_init_origination_credit Tez.one_mutez) ;
+    Test.tztest "valid delegate registration: credit 1μꜩ, self delegation (init with delegation)"
+      `Quick (valid_delegate_registration_init_delegation_credit Tez.one_mutez) ;
+    Test.tztest "valid delegate registration: credit 1μꜩ, self delegation (switch with delegation)"
+      `Quick (valid_delegate_registration_switch_delegation_credit Tez.one_mutez) ;
+    (* valid registration: credit 1 μꜩ, self delegation, debit 1μꜩ *)
+    Test.tztest "valid delegate registration: credit 1μꜩ, self delegation, debit 1μꜩ (origination)"
+      `Quick (valid_delegate_registration_init_origination_credit_debit Tez.one_mutez) ;
+    Test.tztest "valid delegate registration: credit 1μꜩ, self delegation, debit 1μꜩ (init with delegation)"
+      `Quick (valid_delegate_registration_init_delegation_credit_debit Tez.one_mutez) ;
+    Test.tztest "valid delegate registration: credit 1μꜩ, self delegation, debit 1μꜩ (switch with delegation)"
+      `Quick (valid_delegate_registration_switch_delegation_credit_debit Tez.one_mutez) ;
+
+    (*** double registration ***)
+    Test.tztest "double registration" `Quick double_registration ;
+  ]
+
+
+
+(******************************************************************************)
+(* Main                                                                       *)
+(******************************************************************************)
+
+let tests =
+  tests_bootstrap_contracts  @
+  tests_delegate_registration
diff --git a/src/proto_alpha/lib_protocol/test/main.ml b/src/proto_alpha/lib_protocol/test/main.ml
index 117353bac..3a7d04872 100644
--- a/src/proto_alpha/lib_protocol/test/main.ml
+++ b/src/proto_alpha/lib_protocol/test/main.ml
@@ -17,5 +17,6 @@ let () =
     "double baking", Double_baking.tests ;
     "seed", Seed.tests ;
     "baking", Baking.tests ;
+    "delegation", Delegation.tests ;
     "rolls", Rolls.tests ;
   ]