Build a Coinflip dApp with Anchor & Rust on Solana

# Verify your setup
solana --version
anchor --version
rustc --version

anchor init coinflip
cd coinflip

use anchor_lang::prelude::*;
 
declare_id!("YOUR_PROGRAM_ID_HERE");
 
#[program]
pub mod coinflip {
    use super::*;
 
    pub fn create_game(ctx: Context<CreateGame>, wager: u64) -> Result<()> {
        let game = &mut ctx.accounts.game;
        game.player_one = ctx.accounts.player.key();
        game.wager = wager;
        game.state = GameState::Waiting;
        game.bump = ctx

#[derive(AnchorSerialize, AnchorDeserialize, Clone, PartialEq, Eq)]
pub enum GameState {
    Waiting,
    Active,
    Resolved,
}
 
#[account]
pub struct Game {
    pub player_one: Pubkey,
    pub player_two: Pubkey,
    pub winner: Pubkey,
    pub wager: u64,
    pub state: GameState,
    pub bump: u8,
}
 
impl Game {

anchor build
anchor keys list         # Copy the new program ID
# Update declare_id!() in lib.rs and Anchor.toml
anchor deploy --provider.cluster devnet

import * as anchor from "@coral-xyz/anchor";
import { Program } from "@coral-xyz/anchor";
import { Coinflip } from "../target/types/coinflip";
import { PublicKey, SystemProgram, LAMPORTS_PER_SOL } from "@solana/web3.js";
 
const provider = anchor.AnchorProvider.env();
anchor.setProvider(provider);
const program = anchor.workspace.Coinflip as Program<Coinflip>;
 
async function play() {
  const

import { expect } from "chai";
 
describe("coinflip", () => {
  it("creates a game with the correct wager", async () => {
    // ... setup from above ...
    await program.methods.createGame(wager).accounts({ /* ... */ }).rpc();
 
    const gameAccount = await program.account.game.fetch(gamePda);
    expect(gameAccount.wager.toNumber()).to.equal(wager.toNumber

anchor test