idempotent w/ existing ATA

Author: grod220

Cargo.lock

@@ -1,6 +1,13 @@
 [workspace]
 resolver = "2"
-members = ["interface", "program", "mollusk_harness", "pinocchio/interface", "pinocchio/program"]
+members = [
+    "compat",
+    "interface",
+    "mollusk_harness",
+    "pinocchio/interface",
+    "pinocchio/program",
+    "program",
+]
 
 [workspace.metadata.spellcheck]
 config = "scripts/spellcheck.toml"

Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "ata-compat-tests"
+version = "0.1.0"
+edition = "2021"
+description = "Shared compatibility tests for legacy and Pinocchio ATA programs"
+publish = false
+
+[dev-dependencies]
+mollusk-svm = "0.7.2"
+solana-instruction = "3.2.0"
+solana-program-error = "3.0.0"
+solana-program-pack = "3.1.0"
+solana-address = "2.2.0"
+spl-associated-token-account-interface = { version = "2.0.0", path = "../interface" }
+spl-associated-token-account-mollusk-harness = { version = "1.0.0", path = "../mollusk_harness" }
+spl-token-2022-interface = "2.1.0"
+spl-token-interface = "2.0.0"
+test-case = "3.3.1"
+
+[lints]
+workspace = true

compat/Cargo.toml

@@ -0,0 +1,38 @@
+use {
+    mollusk_svm::result::Check,
+    solana_address::Address,
+    solana_program_error::ProgramError,
+    spl_associated_token_account_mollusk_harness::{
+        build_create_ata_instruction, AtaProgramUnderTest, AtaTestHarness, CreateAtaInstructionType,
+    },
+    test_case::test_matrix,
+};
+
+#[test_matrix(
+    [AtaProgramUnderTest::Legacy, AtaProgramUnderTest::Pinocchio],
+    [spl_token_interface::id(), spl_token_2022_interface::id()]
+)]
+fn create_rejects_existing_ata(ata_program: AtaProgramUnderTest, token_program_id: Address) {
+    let harness =
+        AtaTestHarness::new_for(ata_program, &token_program_id).with_wallet_and_mint(1_000_000, 6);
+    let wallet = harness.wallet.unwrap();
+    let mint = harness.mint.unwrap();
+    let ata_address = harness.insert_token_account_at_ata_address(wallet);
+
+    let instruction = build_create_ata_instruction(
+        spl_associated_token_account_interface::program::id(),
+        harness.payer,
+        ata_address,
+        wallet,
+        mint,
+        token_program_id,
+        CreateAtaInstructionType::Create {
+            bump: None,
+            account_len: None,
+        },
+    );
+
+    harness
+        .ctx
+        .process_and_validate_instruction(&instruction, &[Check::err(ProgramError::IllegalOwner)]);
+}