feat(tests): Add test to initialize multiple accounts with the same payer

Author: swaroop-osec

tests/duplicate-mutable-accounts/programs/duplicate-mutable-accounts/src/lib.rs

@@ -56,6 +56,17 @@ pub mod duplicate_mutable_accounts {
         }
         Ok(())
     }
+
+    // Test initializing multiple accounts with the same payer
+    pub fn init_multiple_with_same_payer(
+        ctx: Context<InitMultipleWithSamePayer>,
+        initial1: u64,
+        initial2: u64,
+    ) -> Result<()> {
+        ctx.accounts.data_account1.count = initial1;
+        ctx.accounts.data_account2.count = initial2;
+        Ok(())
+    }
 }
 
 #[account]
@@ -115,3 +126,15 @@ pub struct UseRemainingAccounts<'info> {
     #[account(mut)]
     pub account1: Account<'info, Counter>,
 }
+
+// Test initializing multiple accounts with the same payer
+#[derive(Accounts)]
+pub struct InitMultipleWithSamePayer<'info> {
+    #[account(init, payer = user, space = 8 + 8)]
+    pub data_account1: Account<'info, Counter>,
+    #[account(init, payer = user, space = 8 + 8)]
+    pub data_account2: Account<'info, Counter>,
+    #[account(mut)]
+    pub user: Signer<'info>,
+    pub system_program: Program<'info, System>,
+}

tests/duplicate-mutable-accounts/tests/duplicate-mutable-accounts.ts

@@ -191,4 +191,44 @@ describe("duplicate-mutable-accounts", () => {
       "Account1 should be incremented"
     );
   });
+
+  it("Should allow initializing multiple accounts with the same payer", async () => {
+    // Create two new keypairs for the accounts to be initialized
+    const newAccount1 = anchor.web3.Keypair.generate();
+    const newAccount2 = anchor.web3.Keypair.generate();
+
+    // Initialize both accounts using the same payer
+    // This should succeed because:
+    // 1. The payer is a Signer, which is excluded from duplicate checks
+    // 2. The accounts being initialized are different (newAccount1 vs newAccount2)
+    await program.methods
+      .initMultipleWithSamePayer(new anchor.BN(500), new anchor.BN(600))
+      .accounts({
+        dataAccount1: newAccount1.publicKey,
+        dataAccount2: newAccount2.publicKey,
+        user: user_wallet.publicKey,
+        systemProgram: anchor.web3.SystemProgram.programId,
+      })
+      .signers([user_wallet, newAccount1, newAccount2])
+      .rpc();
+
+    // Verify both accounts were created with correct values
+    const account1Data = await program.account.counter.fetch(
+      newAccount1.publicKey
+    );
+    const account2Data = await program.account.counter.fetch(
+      newAccount2.publicKey
+    );
+
+    assert.equal(
+      account1Data.count.toNumber(),
+      500,
+      "First account should have count 500"
+    );
+    assert.equal(
+      account2Data.count.toNumber(),
+      600,
+      "Second account should have count 600"
+    );
+  });
 });