Adder collator improvements (#1896)

* Fixes bug that collator wasn't sending `Declare` message

* Set authority discovery config

* Fixes bug that collator wasn't sending `Declare` message

* Adds real overseer feature and makes the wasm_validation fail with a
proper error

* Adds README

* Remove debug stuff

* Add feature

* Make adder collator use the correct parent when building a new block

polkadot/parachain/test-parachains/adder/src/lib.rs

@@ -58,7 +58,7 @@ impl HeadData {
 }
 
 /// Block data for this parachain.
-#[derive(Default, Clone, Encode, Decode)]
+#[derive(Default, Clone, Encode, Decode, Debug)]
 pub struct BlockData {
 	/// State to begin from.
 	pub state: u64,

polkadot/parachain/test-parachains/adder/src/wasm_validation.rs

@@ -32,15 +32,13 @@ pub extern fn validate_block(params: *const u8, len: usize) -> u64 {
 
 	let parent_hash = tiny_keccak::keccak256(&params.parent_head.0[..]);
 
-	match crate::execute(parent_hash, parent_head, &block_data) {
-		Ok(new_head) => parachain::write_result(
-			&ValidationResult {
-				head_data: GenericHeadData(new_head.encode()),
-				new_validation_code: None,
-				upward_messages: sp_std::vec::Vec::new(),
-				processed_downward_messages: 0,
-			}
-		),
-		Err(_) => panic!("execution failure"),
-	}
+	let new_head = crate::execute(parent_hash, parent_head, &block_data).expect("Executes block");
+	parachain::write_result(
+		&ValidationResult {
+			head_data: GenericHeadData(new_head.encode()),
+			new_validation_code: None,
+			upward_messages: sp_std::vec::Vec::new(),
+			processed_downward_messages: 0,
+		}
+	)
 }