bun run clarity-patterns/clarity-patterns.ts <subcommand> [options]

(define-public (transfer (amount uint) (to principal))
  (begin
    (asserts! (is-eq tx-sender owner) ERR_UNAUTHORIZED)
    (try! (ft-transfer? TOKEN amount tx-sender to))
    (ok true)))

(print {
  notification: "contract-event",
  payload: {
    amount: amount,
    sender: tx-sender,
    recipient: to
  }
})

(match (contract-call? .other fn args)
  success (ok success)
  error (err ERR_EXTERNAL_CALL_FAILED))

(define-constant STATUS_ACTIVE (pow u2 u0))   ;; 1
(define-constant STATUS_PAID (pow u2 u1))     ;; 2
(define-constant STATUS_VERIFIED (pow u2 u2)) ;; 4

;; Pack multiple flags: (+ STATUS_ACTIVE STATUS_PAID) → u3
;; Check flag: (> (bit-and status STATUS_ACTIVE) u0)
;; Set flag: (var-set status (bit-or (var-get status) NEW_FLAG))
;; Clear flag: (var-set status (bit-and (var-get status) (bit-not FLAG)))

(define-private (send-maybe
    (recipient {to: principal, ustx: uint})
    (prior (response bool uint)))
  (match prior
    ok-result (let (
      (to (get to recipient))
      (ustx (get ustx recipient)))
      (try! (stx-transfer? ustx tx-sender to))
      (ok true))
    err-result (err err-result)))

(define-public (send-many (recipients (list 200 {to: principal, ustx: uint})))
  (fold send-maybe recipients (ok true)))

(define-map Parents uint {name: (string-ascii 32), lastChildId: uint})
(define-map Children {parentId: uint, id: uint} uint)

(define-read-only (get-child (parentId uint) (childId uint))
  (map-get? Children {parentId: parentId, id: childId}))

(define-private (is-some? (x (optional uint)))
  (is-some x))

(define-read-only (get-children (parentId uint) (shift uint))
  (filter is-some?
    (list
      (get-child parentId (+ shift u1))
      (get-child parentId (+ shift u2))
      (get-child parentId (+ shift u3))
      ;; ... up to page size
    )))

(define-map Allowed {contract: principal, type: uint} bool)

;; Check in function
(asserts! (default-to false (map-get? Allowed {contract: contract, type: type}))
          ERR_NOT_ALLOWED)

;; Batch update
(define-public (set-allowed-list (items (list 100 {token: principal, enabled: bool})))
  (ok (map set-iter items (ok true))))

(define-map TrustedTraits principal bool)

;; In functions accepting traits
(asserts! (default-to false (map-get? TrustedTraits (contract-of t)))
          ERR_UNTRUSTED)

(define-constant DELAY u21000) ;; ~146 days in BTC blocks
(define-data-var activation-block uint u0)

;; Set on deploy or init
(var-set activation-block (+ burn-block-height DELAY))

(define-read-only (is-active?)
  (>= burn-block-height (var-get activation-block)))

(define-data-var last-action-block uint u0)

(define-public (rate-limited-action)
  (begin
    (asserts! (> burn-block-height (var-get last-action-block)) ERR_RATE_LIMIT)
    (var-set last-action-block burn-block-height)
    ;; ... action
    (ok true)))

(define-map Proposals uint {
  votesFor: uint,
  votesAgainst: uint,
  status: uint,
  liquidTokens: uint,
  blockHash: (buff 32)
})

;; Get voting power at proposal creation
(define-read-only (get-vote-power (proposal-id uint) (voter principal))
  (let ((proposal (unwrap! (map-get? Proposals proposal-id) u0)))
    (at-block (get blockHash proposal)
      (contract-call? .token get-balance voter))))

;; Quorum check: (>= (/ (* total-votes u100) liquid-supply) QUORUM_PERCENT)

(define-constant SCALE (pow u10 u8)) ;; 8 decimal places

;; Multiply then divide to preserve precision
(define-read-only (calculate-share (amount uint) (percentage uint))
  (/ (* amount percentage) SCALE))

;; Convert to/from scaled values
(define-read-only (to-scaled (amount uint))
  (* amount SCALE))

(define-read-only (from-scaled (amount uint))
  (/ amount SCALE))

(define-public (withdraw (amount uint) (recipient principal))
  (begin
    (asserts! (is-authorized tx-sender) ERR_UNAUTHORIZED)
    (as-contract (stx-transfer? amount (as-contract tx-sender) recipient))))

(as-contract
  (with-stx u1000000)                              ;; Allow 1 STX
  (with-ft .token TOKEN u500)                      ;; Allow 500 fungible tokens
  (with-nft .nft-contract NFT (list u1 u2 u3))    ;; Allow specific NFT IDs
  ;; ... body
)

;; DANGER: Avoid unless necessary
(with-all-assets-unsafe)

;; Proposal state
(define-map Intents uint {
  participants: (list 20 principal),
  accepts: uint,     ;; Bitmask of who accepted
  status: uint,      ;; 0=pending, 1=ready, 2=executed, 3=cancelled
  expiry: uint,
  payload: (buff 256)
})

;; Accept via signature verification
(define-public (accept (intent-id uint) (signature (buff 65)))
  (let (
    (intent (unwrap! (map-get? Intents intent-id) ERR_NOT_FOUND))
    (msg-hash (sha256 (concat (int-to-ascii intent-id) (get payload intent))))
    (signer (try! (secp256k1-recover? msg-hash signature))))
    ;; Verify signer is participant, update accepts bitmask
    (ok true)))

;; Full snapshot — comprehensive (use for high-value records)
(define-private (capture-snapshot)
  {
    stacksBlock: stacks-block-height,
    burnBlock: burn-block-height,
    tenure: tenure-height,
    blockTime: stacks-block-time,
    chainId: chain-id,
    txSender: tx-sender,
    contractCaller: contract-caller,
    txSponsor: tx-sponsor?,
    stacksBlockHash: (get-stacks-block-info? id-header-hash (- stacks-block-height u1)),
    burnBlockHash: (get-burn-block-info? header-hash (- burn-block-height u1))
  }
)

;; Standard snapshot — balanced cost
;; {stacksBlock, burnBlock, blockTime, txSender}

;; Minimal snapshot — cheapest
;; {stacksBlock, burnBlock}

(define-map Registry
  principal
  {
    stacksBlock: uint,
    burnBlock: uint,
    count: uint
  }
)

(map-get? Registry address)
(map-set Registry tx-sender {...})

(define-map Registry
  (buff 32)
  {
    attestor: principal,
    stacksBlock: uint
  }
)

;; First attestor wins
(asserts! (is-none (map-get? Registry hash)) ERR_ALREADY_EXISTS)
(map-set Registry hash {...})

(define-map Registry
  {entity: principal, action: uint}
  {stacksBlock: uint}
)

(map-get? Registry {entity: address, action: action-id})

;; Primary: hash -> data
(define-map Attestations (buff 32) {...})

;; Secondary: address + index -> hash
(define-map AttestorIndex
  {attestor: principal, index: uint}
  (buff 32)
)

;; Counter for next index
(define-map AttestorCount principal uint)

;; On insert:
(let ((idx (default-to u0 (map-get? AttestorCount attestor))))
  (map-set AttestorIndex {attestor: attestor, index: idx} hash)
  (map-set AttestorCount attestor (+ idx u1)))

;; Enumerate:
(define-read-only (get-attestor-hash-at (attestor principal) (index uint))
  (map-get? AttestorIndex {attestor: attestor, index: index}))

(define-data-var totalEntries uint u0)
(define-data-var uniqueAddresses uint u0)

;; On new entry:
(var-set totalEntries (+ (var-get totalEntries) u1))
(if isNewAddress
  (var-set uniqueAddresses (+ (var-get uniqueAddresses) u1))
  true)

;; Read stats:
(define-read-only (get-stats)
  {
    totalEntries: (var-get totalEntries),
    uniqueAddresses: (var-get uniqueAddresses)
  }
)

(define-public (attest (key (buff 32)))
  (begin
    (asserts! (is-none (map-get? Registry key)) ERR_ALREADY_EXISTS)
    (map-set Registry key {...})
    (ok true)))

(define-public (check-in)
  (begin
    (map-set Registry tx-sender {...})
    (ok true)))

(define-map History
  {address: principal, index: uint}
  {...snapshot...}
)

(define-public (record)
  (let ((idx (default-to u0 (map-get? HistoryCount tx-sender))))
    (map-set History {address: tx-sender, index: idx} {...})
    (map-set HistoryCount tx-sender (+ idx u1))
    (ok idx)))

(define-public (register)
  (ok (map-set Registry tx-sender {...})))

(define-public (update (data (buff 64)))
  (begin
    (asserts! (is-some (map-get? Registry tx-sender)) ERR_NOT_REGISTERED)
    (map-set Registry tx-sender {...})
    (ok true)))

(define-data-var admin principal CONTRACT_OWNER)

(define-public (register-address (address principal))
  (begin
    (asserts! (is-eq tx-sender (var-get admin)) ERR_UNAUTHORIZED)
    (map-set Registry address {...})
    (ok true)))

Stxer (Historical Simulation)      — Mainnet fork, pre-deployment validation
RV (Property-Based Fuzzing)        — Invariants, edge cases, battle-grade
Vitest + Clarinet SDK              — Integration tests, TypeScript
Clarunit                           — Unit tests in Clarity itself

import { defineConfig } from "vitest/config";
import { vitestSetupFilePath, getClarinetVitestsArgv } from "@hirosystems/clarinet-sdk/vitest";

export default defineConfig({
  test: {
    environment: "clarinet",
    singleThread: true,
    setupFiles: [vitestSetupFilePath],
    environmentOptions: {
      clarinet: getClarinetVitestsArgv(),
    },
  },
});

import { Cl } from "@stacks/transactions";
import { describe, expect, it } from "vitest";

describe("my-contract", function () {
  it("transfers tokens correctly", function () {
    // ARRANGE
    const deployer = simnet.deployer;
    const wallet1 = simnet.getAccounts().get("wallet_1")!;
    const amount = 100;

    // ACT
    const result = simnet.callPublicFn(
      "my-contract",
      "transfer",
      [Cl.uint(amount), Cl.principal(wallet1)],
      deployer
    );

    // ASSERT
    expect(result.result).toBeOk(Cl.bool(true));
  });
});

import { Cl, cvToValue, cvToJSON } from "@stacks/transactions";

Cl.uint(100)                           // uint
Cl.int(-50)                            // int
Cl.bool(true)                          // bool
Cl.principal("SP123...")               // principal
Cl.contractPrincipal("SP123", "name")  // contract principal
Cl.stringAscii("hello")               // (string-ascii N)
Cl.stringUtf8("hello")                // (string-utf8 N)
Cl.bufferFromHex("deadbeef")           // (buff N)
Cl.tuple({ amount: Cl.uint(100) })     // tuple
Cl.list([Cl.uint(1), Cl.uint(2)])      // list
Cl.some(Cl.uint(100))                  // (some value)
Cl.none()                              // none

expect(result.result).toBeOk(Cl.uint(100));
expect(result.result).toBeErr(Cl.uint(1));
expect(result.result).toBeBool(true);
expect(result.result).toBeUint(100);
expect(result.result).toBePrincipal("SP123...");

;; Property: loan amount always increases correctly
(define-public (test-borrow (amount uint))
  (if (is-eq amount u0)
    (ok false)  ;; Discard invalid input
    (let ((initial (get-loan tx-sender)))
      (try! (borrow amount))
      (asserts! (is-eq (get-loan tx-sender) (+ initial amount))
        (err u999))
      (ok true))))

;; Invariant: total supply never exceeds cap
(define-read-only (invariant-supply-capped)
  (<= (var-get total-supply) MAX_SUPPLY))

;; @name Multiplication works correctly
(define-public (test-multiply)
  (begin
    (asserts! (is-eq u8 (contract-call? .math multiply u2 u4))
      (err "2 * 4 should equal 8"))
    (ok true)))

my-project/
├── Clarinet.toml
├── vitest.config.js
├── package.json
├── contracts/
│   ├── my-contract.clar
│   └── my-contract.tests.clar      # RV tests
├── tests/
│   ├── my-contract.test.ts         # Vitest
│   ├── my-contract_test.clar       # Clarunit
│   └── clarunit.test.ts            # Clarunit runner
└── simulations/
    └── my-contract-stxer.ts        # Stxer

{
  "scripts": {
    "test": "vitest run",
    "test:watch": "vitest",
    "test:rv": "npx rv . my-contract test",
    "test:rv:invariant": "npx rv . my-contract invariant",
    "test:stxer": "npx tsx simulations/my-contract-stxer.ts"
  }
}