Make changes needed for TCR

contracts/RegistryApp.sol

@@ -1,6 +1,8 @@
 pragma solidity ^0.4.15;
 
-import "@aragon/core/contracts/apps/App.sol";
+import "@aragon/os/contracts/apps/AragonApp.sol";
+import "./interfaces/IRegistry.sol";
+
 
 /**
  * A generic registry app.
@@ -11,49 +13,63 @@ import "@aragon/core/contracts/apps/App.sol";
  * the rules for who can add and remove entries in the registry, it becomes
  * a powerful building block (examples are token-curated registries and stake machines).
  */
-contract RegistryApp is App {
+contract RegistryApp is IRegistry, AragonApp {
     // The entries in the registry.
-    mapping(bytes32 => bytes32) entries;
+    mapping(bytes32 => bytes) entries;
 
     // Fired when an entry is added to the registry.
     event EntryAdded(bytes32 id);
     // Fired when an entry is removed from the registry.
     event EntryRemoved(bytes32 id);
 
-    bytes32 public constant ADD_ENTRY_ROLE = bytes32(1);
-    bytes32 public constant REMOVE_ENTRY_ROLE = bytes32(2);
+    bytes32 public constant ADD_ENTRY_ROLE = bytes32("ADD_ENTRY_ROLE");
+    bytes32 public constant REMOVE_ENTRY_ROLE = bytes32("REMOVE_ENTRY_ROLE");
+
+    /**
+     * @notice Initialize App
+     */
+    function initialize() onlyInit external {
+        initialized();
+    }
 
     /**
      * Add an entry to the registry.
      * @param _data The entry to add to the registry
      */
-    function add(
-        bytes32 _data
-    ) public auth(ADD_ENTRY_ROLE) returns (bytes32 _id) {
+    function add(bytes _data) isInitialized public auth(ADD_ENTRY_ROLE) returns (bytes32 _id) {
         _id = keccak256(_data);
-        entries[_id] = _data;
+        require(!exists(_id));
 
+        entries[_id] = _data;
         EntryAdded(_id);
     }
 
     /**
      * Remove an entry from the registry.
      * @param _id The ID of the entry to remove
      */
-    function remove(
-        bytes32 _id
-    ) public auth(REMOVE_ENTRY_ROLE) {
+    function remove(bytes32 _id) isInitialized public auth(REMOVE_ENTRY_ROLE) {
+        require(exists(_id));
+
         delete entries[_id];
         EntryRemoved(_id);
     }
 
     /**
      * Get an entry from the registry.
      * @param _id The ID of the entry to get
+     * @return The entry data
      */
-    function get(
-        bytes32 _id
-    ) public constant returns (bytes32) {
+    function get(bytes32 _id) isInitialized public view returns (bytes) {
         return entries[_id];
     }
+
+    /**
+     * Check if an entry is in the registry.
+     * @param _id The ID of the entry to get
+     * @return True if it's in the registry, false otherwise
+     */
+    function exists(bytes32 _id) public view returns (bool) {
+        return entries[_id].length > 0;
+    }
 }

contracts/interfaces/IRegistry.sol

@@ -0,0 +1,16 @@
+pragma solidity ^0.4.18;
+
+
+interface IRegistry {
+    function add(bytes _data) public returns (bytes32 _id);
+    function remove(bytes32 _id) public;
+    function exists(bytes32 _id) public view returns (bool);
+}
+
+
+contract FakeRegistry {
+    // to work around coverage issue
+    function fake() public pure {
+        // for lint
+    }
+}