docs: common contract errors (#2471)

Fixes #2468

docs/docs/dev_docs/contracts/common_errors.md

@@ -1,9 +1,53 @@
-# Errors
-
-List common errors.
+# Common Errors
 
 There are two kinds of errors: errors in an Aztec.nr contract, and errors spat out by an Aztec Sandbox node!
+This section will provide an overview of the errors you might encounter, and how to fix them.
+
+### Assertion Error
+
+This error is thrown when a condition is not met.
+
+This is what the error typically looks like:
+```
+Simulation error: Assertion failed: Balance too low 'sum == amount'
+```
+
+To address the error. find the line in the contract that is throwing the error and investigate why the condition is not met.
+
+### Unknown Contract Error
+This error occurs when you are trying to interact with a smart contract via an Aztec RPC Server that does not have the necessary information to execute a transaction.
+
+This is what the error typically looks like:
+```
+Unknown contract 0x1d206be10b873b78b875259e1a8c39e2212e2f181d2fd0b0407446487deba522: add it to Aztec RPC server by calling server.addContracts(...)
+```
+
+To execute a transaction, the Aztec RPC Server needs to know the complete address of a contract, portal address (if portal is used) and contract artifacts.
+
+To address the error, add the contract to the Aztec RPC Server by calling `server.addContracts(...)`.
+
+### Unknown Complete Address Error
+This error occurs when your contract is trying to get a public key via the `get_public_key` oracle call, but the Aztec RPC Server does not have the Complete Address (Complete Address contains the public key).
+
+This is what the error typically looks like:
+```
+Simulation error: Unknown complete address for address 0x0d179a5f9bd4505f7dfb8ca37d64e0bd0cd31b5cb018e252fd647bdf88959b95. Add the information to Aztec RPC server by calling server.registerRecipient(...) or server.registerAccount(...)
+```
+
+Your contract typically needs a public key when it wants to send a note to a recipient because the public key is used to encrypt notes.
+
+:::info
+Manually adding the recipient to the Aztec RPC Server should not be required in case the recipient contract has already been deployed and the Aztec RPC Server is fully synced.
+This is because this information is submitted on-chain when the recipient contract is deployed.
+:::
+
+### Unknown account
+This error occurs when your contract is trying to get a secret via the `get_secret` oracle call, but the Aztec RPC Server does not have the secret for the public key.
 
-Maybe even auto-generate error docs, based on error codes in our codebase.
+This is what the error typically looks like:
+```
+Could not process note because of "Error: Unknown account.". Skipping note...
+```
 
-Make sure descriptions of errors relate to the end user experience. An error like 'SegFault' is useless to a contract developer!
+This error might occurr when you register an account only as a recipient and not as an account.
+To address the error, register the account by calling `server.registerAccount(...)`.

docs/sidebars.js

@@ -272,6 +272,7 @@ const sidebars = {
             "dev_docs/contracts/portals/outbox",
           ],
         },
+        "dev_docs/contracts/common_errors",
         // {
         //   label: "Resources",
         //   type: "category",