Solana Course (Anchor + Rust)

Hands-on Solana learning repo with small daily programs (day_1 to day_X) and TypeScript tests.

This README is written for learning: each section explains what to run and why it matters.

1. What You Will Learn

• How to write Anchor programs in Rust.
• How to call instructions from TypeScript tests.
• How account validation works (Context<...> and #[derive(Accounts)]).
• How errors and require! behave in Solana programs.
• How IDL files connect on-chain Rust code to off-chain clients.
• How to build, deploy, and test each program on localnet.

2. Project Layout

programs/
  day_1 ... day_X/       # Solana programs (Rust + Anchor)
tests/
  day_1.ts ... day_5.ts  # Client-side tests (TypeScript + Anchor)
Anchor.toml              # Program IDs, localnet config, test script
Makefile                 # Day-specific deploy/test shortcuts

3. Prerequisites

Install and verify:

• Rust (toolchain in this repo is pinned in rust-toolchain.toml).
• Solana CLI (solana --version).
• Anchor CLI (anchor --version).
• Node.js + Yarn (node -v, yarn -v).

If your wallet is not set up yet:

solana-keygen new
solana config set --url http://127.0.0.1:8899

4. Quick Start

Install JavaScript dependencies:

yarn install

Build all programs:

anchor build

Start local validator (terminal 1):

solana-test-validator --reset

Run tests against that validator (terminal 2):

anchor test --skip-local-validator

5. Day-by-Day Learning Path

Day 1: First instruction

• File: programs/day_1/src/lib.rs
• Test: tests/day_1.ts
• Goal: call a basic instruction (initialize) and confirm your local setup works.

Day 2: Types, vectors, and safe arithmetic

• File: programs/day_2/src/lib.rs
• Test: tests/day_2.ts
• Goal: pass u64, String, and Vec<u64> from TypeScript into Rust.
• Practice safe math with checked_add, checked_sub, checked_mul, checked_div, and checked_pow.

Day 3: Accounts context patterns

• File: programs/day_3/src/lib.rs
• Test: tests/day_3.ts
• Goal: compare an instruction with required signer accounts vs an instruction with empty accounts.

Day 4: Custom errors and validation

• File: programs/day_4/src/lib.rs
• Test: tests/day_4.ts
• Goal: use require! and custom #[error_code] enums, then assert those errors in tests.

Day 5: IDL and manual client creation

• File: programs/day_5/src/lib.rs
• Test: tests/day_5.ts
• Goal: instantiate an Anchor Program client manually from target/idl/day_5.json.

Day 6: Scaffold for next lessons

• File: programs/day_6/src/lib.rs
• Goal: starter module ready for extending with new topics.

6. Useful Commands

Local validator

solana-test-validator
solana-test-validator --reset

Build and key sync

anchor build
anchor keys sync

Run specific day with Makefile

make test DAY=day_2
# or shortcut:
make test-day_2

Run all tests (with existing local validator)

anchor test --skip-local-validator

Wallet and airdrop

solana address
solana balance
solana airdrop 2

Logs and program logs

solana logs
ls .anchor/program-logs/

7. Core Concepts (Practical)

u64 in Solana programs

Many examples use u64 because it is a common integer type for balances, counters, and amounts. In TypeScript tests, pass large integers using BN (bn.js) to avoid JavaScript number limits.

Overflow and safe math

Rust can panic on overflow depending on build settings, but in on-chain code you should prefer explicit safe math:

• checked_* returns Option<T>.
• Handle None and return a program error when needed.

This repo shows safe math patterns in day_2.

Compute units

Each transaction has a compute budget. If your instruction uses too much compute, the transaction fails. Small code choices can change compute usage, so test and measure while optimizing.

IDL (Interface Definition Language)

Anchor generates IDL JSON files under target/idl/. IDL describes instruction names, arguments, and account requirements so clients can call your program safely.

Equivalent mental model for Solidity developers: IDL is similar to ABI metadata.

Note: Rust snake_case instruction names become camelCase in TypeScript clients.

Errors and require!

Use require!(condition, CustomError) for guard checks. If a condition fails, your instruction returns an error and the transaction is reverted. day_4 demonstrates both success and failure test cases.

Reference: https://www.anchor-lang.com/docs/features/errors

Deployment and upgrades

Anchor deploys upgradeable programs by default (upgrade authority exists). You can upgrade while authority is active; removing authority makes the program immutable. For tests, --skip-deploy or --skip-local-validator helps target an already running environment.

8. Common Learning Workflow

1. Start validator: solana-test-validator --reset
2. Build programs: anchor build
3. Run one lesson: make test DAY=day_4
4. Inspect logs: solana logs
5. Modify program logic and rerun the same day

Repeat this loop until you can explain both the Rust instruction and the TypeScript call path.

9. Troubleshooting

• AccountNotFound or signer errors: verify account constraints in the instruction Context.
• Program ID mismatch: run anchor keys sync and rebuild.
• Wallet has no SOL: run solana airdrop 2.
• Tests target wrong RPC: ensure provider points to localnet (http://127.0.0.1:8899).