From 2077981a70daa76ea31c3fcd6718f26f237848ad Mon Sep 17 00:00:00 2001
From: Costa Giannakakis <77694967+costa2400@users.noreply.github.com>
Date: Mon, 4 Mar 2024 02:55:11 -0500
Subject: [PATCH] expanded guide

---
 src/basics.md | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 71 insertions(+), 1 deletion(-)

diff --git a/src/basics.md b/src/basics.md
index abc8303..8fec67c 100644
--- a/src/basics.md
+++ b/src/basics.md
@@ -48,4 +48,74 @@ In this chapter, we will go through creating essential smart contracts step by s
 5. **Business Logic**
     - Flesh out the business logic within the **`execute`** function. Consider edge cases and input validation to ensure contract security and reliability.
 6. **Testing**
-    - Write unit tests for each entry point and critical functions within your contract. Use **`cargo test`** to run your tests. Consider edge cases and invalid inputs to ensure your contract behaves as expected under various conditions.
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+    - Write unit tests for each entry point and critical functions within your contract. Use **`cargo test`** to run your tests. Consider edge cases and invalid inputs to ensure your contract behaves as expected under various conditions.
+
+### **Expanded Guide to Creating Essential Smart Contracts in CosmWasm**
+
+### Error Handling
+
+**How to Handle Errors:**
+
+- Implement robust error handling using Rust's **`Result`** and **`Option`** types. Utilize custom error types defined with **`thiserror`** to provide clear, actionable error messages.
+- Use **`?`** for error propagation within your contract functions to keep your code clean and readable.
+
+### Migration Function
+
+**How to Implement Migration:**
+
+- The **`migrate`** function allows contract upgrades. Define it similarly to **`instantiate`** and **`execute`**, but focus on transitioning from one contract state version to another safely.
+- Ensure data integrity and compatibility between versions. Test migrations thoroughly in a controlled environment before deploying.
+
+### External Crates Usage
+
+**Examples of Compatible Crates:**
+
+- **`serde_json`** for JSON serialization/deserialization.
+- **`cw-storage-plus`** for advanced storage patterns.
+- Always check the crate's documentation for **`no_std`** compatibility or specific instructions for Wasm targets.
+
+### Interaction Patterns
+
+**Cross-Contract Calls:**
+
+- Use the **`CosmosMsg::Wasm(WasmMsg::Execute { ... })`** pattern to call other contracts. Handle responses using the **`SubMsg`** pattern for asynchronous execution.
+- Consider the implications of external calls failing and implement fallback or retry logic as needed.
+
+### Security Practices
+
+**Smart Contract Security:**
+
+- Avoid common pitfalls like reentrancy by carefully managing state changes and external calls.
+- Utilize Rust's strong type system to prevent issues like overflow/underflow.
+- Regularly audit your contracts and consider third-party reviews for critical applications.
+
+### Optimization Tips
+
+**Gas Efficiency:**
+
+- Minimize storage access, as it's typically the most expensive operation. Cache results when possible.
+- Use iterators wisely. Avoid loading entire datasets into memory when a filter or map operation can be applied directly.
+
+### Deployment and Testing on a Blockchain
+
+**Blockchain Testing and Deployment:**
+
+- Use **`wasmd`** for local testing and deployment simulations. Familiarize yourself with **`wasmd`** CLI commands for deploying and interacting with your contracts.
+- Test your contract on a public testnet to ensure it behaves as expected in a real blockchain environment.
+
+### Tooling and IDE Setup
+
+**Recommended Development Tools:**
+
+- Visual Studio Code with the Rust Analyzer extension for Rust development.
+- Use **`cargo-contract`** for contract compilation and artifact generation.
+- Integrate debugging tools like **`console_error_panic_hook`** for better error visibility in Wasm.
+
+### Community Resources and Support
+
+**Engaging with the Community:**
+
+- Join the CosmWasm GitHub discussions and Discord server for support and to connect with other developers.
+- Stay updated with the latest CosmWasm releases and best practices by following the official CosmWasm documentation and blog.
+
+By addressing these areas, developers are equipped with a deeper understanding and practical tools to navigate the complexities of smart contract development in CosmWasm. This expanded guide aims to foster the creation of secure, efficient, and maintainable smart contracts within the Cosmos ecosystem.
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