Add missing constraints for internal transactions

Calls didn't enforce that `call_type` and `input` was not `NULL`.
Creates didn't enforce that `init` was not `NULL`.

apps/explorer/lib/explorer/chain/internal_transaction.ex

@@ -376,6 +376,8 @@ defmodule Explorer.Chain.InternalTransaction do
     |> cast(attrs, @call_allowed_fields)
     |> validate_required(@call_required_fields)
     |> validate_call_error_or_result()
+    |> check_constraint(:call_type, message: ~S|can't be blank when type is 'call'|, name: :call_has_call_type)
+    |> check_constraint(:input, message: ~S|can't be blank when type is 'call'|, name: :call_has_call_type)
     |> foreign_key_constraint(:from_address_hash)
     |> foreign_key_constraint(:to_address_hash)
     |> foreign_key_constraint(:transaction_hash)
@@ -391,6 +393,7 @@ defmodule Explorer.Chain.InternalTransaction do
     |> cast(attrs, @create_allowed_fields)
     |> validate_required(@create_required_fields)
     |> validate_create_error_or_result()
+    |> check_constraint(:init, message: ~S|can't be blank when type is 'create'|, name: :create_has_init)
     |> foreign_key_constraint(:created_contract_address_hash)
     |> foreign_key_constraint(:from_address_hash)
     |> foreign_key_constraint(:transaction_hash)

apps/explorer/priv/repo/migrations/20181108205650_additional_internal_transaction_constraints.exs

@@ -0,0 +1,15 @@
+defmodule Explorer.Repo.Migrations.AdditionalInternalTransactionConstraints do
+  use Ecto.Migration
+
+  def up do
+    create(constraint(:internal_transactions, :call_has_call_type, check: "type != 'call' OR call_type IS NOT NULL"))
+    create(constraint(:internal_transactions, :call_has_input, check: "type != 'call' OR input IS NOT NULL"))
+    create(constraint(:internal_transactions, :create_has_init, check: "type != 'create' OR init IS NOT NULL"))
+  end
+
+  def down do
+    drop(constraint(:internal_transactions, :call_has_call_type))
+    drop(constraint(:internal_transactions, :call_has_input))
+    drop(constraint(:internal_transactions, :create_has_init))
+  end
+end

apps/explorer/test/support/factory.ex

@@ -269,7 +269,8 @@ defmodule Explorer.Factory do
       call_type: :delegatecall,
       gas: gas,
       gas_used: gas_used,
-      output: %Data{bytes: <<1>>},
+      input: %Data{bytes: <<1>>},
+      output: %Data{bytes: <<2>>},
       # caller MUST supply `index`
       trace_address: [],
       # caller MUST supply `transaction` because it can't be built lazily to allow overrides without creating an extra