fix(tests): align test fixtures with Quasar's compact wire format

The Quasar `#[account]` and `#[instruction]` derive macros use a single
"compact" wire layout: a header containing all fixed-size fields and
length prefixes grouped together, followed by a tail with all dynamic
byte payloads grouped together. The previous tests assumed an
interleaved field-by-field layout with u32 length prefixes, which never
matched the program code that was already migrated to the compact
format.

Two consequences flowed from that mismatch:

1. Length prefixes for `String<MAX>` default to a single byte (the
   second `String` generic argument is the prefix type and its default
   is `u8`). The tests were using u32 prefixes, so the program rejected
   the instruction data or wrote wildly wrong account contents.

2. The compact format groups all length prefixes ahead of the data
   bytes; the tests expected each prefix to immediately precede its
   own bytes.

This commit rewrites the failing test fixtures so they encode and
decode the same compact format the programs already produce. The
program code itself is not changed — programs are canonical, tests
follow.

Also removes a stray `rent` sysvar account from the
`tokens/pda-mint-authority` `create_mint` test: the program's
`CreateMint` accounts struct no longer takes a rent sysvar, so the
extra entry was shifting `token_program` and `system_program` to
the wrong slots.

Projects fixed:
  basics/account-data
  basics/close-account
  basics/favorites
  basics/realloc
  basics/rent
  basics/repository-layout
  tokens/pda-mint-authority

Author: Edward (Mike's assistant)

basics/account-data/quasar/src/tests.rs

@@ -20,28 +20,28 @@ fn empty(address: Pubkey) -> Account {
     }
 }
 
-/// Build create_address_info instruction data manually.
+/// Build the create_address_info instruction data using Quasar's compact
+/// wire format: a header containing all fixed fields and length prefixes,
+/// followed by a tail with all dynamic byte payloads grouped together.
 ///
-/// Wire format (from reading the #[instruction] codegen):
-///   [disc: 1 byte]
-///   [ZC struct: house_number u8]
-///   [name: u32 LE length prefix + bytes]  (String → DynKind::Str with U32 prefix)
-///   [street: u32 LE length prefix + bytes]
-///   [city: u32 LE length prefix + bytes]
+/// Layout:
+///   header: [disc: u8 = 0][house_number: u8][name_len: u8][street_len: u8][city_len: u8]
+///   tail:   [name bytes][street bytes][city bytes]
+///
+/// `String<50>` defaults to a u8 length prefix because MAX (50) fits in a byte.
 fn build_create_instruction_data(name: &str, house_number: u8, street: &str, city: &str) -> Vec<u8> {
-    let mut data = vec![0u8]; // discriminator = 0
+    let mut data = Vec::with_capacity(5 + name.len() + street.len() + city.len());
 
-    // Fixed ZC struct: house_number
+    // Header
+    data.push(0u8); // instruction discriminator
     data.push(house_number);
+    data.push(name.len() as u8);
+    data.push(street.len() as u8);
+    data.push(city.len() as u8);
 
-    // Dynamic String args with u32 length prefix
-    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
+    // Tail
     data.extend_from_slice(name.as_bytes());
-
-    data.extend_from_slice(&(street.len() as u32).to_le_bytes());
     data.extend_from_slice(street.as_bytes());
-
-    data.extend_from_slice(&(city.len() as u32).to_le_bytes());
     data.extend_from_slice(city.as_bytes());
 
     data
@@ -81,34 +81,25 @@ fn test_create_address_info() {
     // Verify the account data.
     let account = result.account(&address_info).unwrap();
 
-    // Onchain layout (from #[account] dynamic codegen):
-    //   [disc: 1 byte = 1]
-    //   [ZC header: house_number u8]
-    //   [name: u8 prefix + bytes]   (String<u8, 50> uses u8 prefix)
-    //   [street: u8 prefix + bytes]
-    //   [city: u8 prefix + bytes]
+    // Onchain layout for a Quasar `#[account]` with dynamic fields uses the
+    // compact "header then tail" format. Length prefixes are grouped in the
+    // header, the actual bytes follow in the tail.
+    //   header: [disc: 1][house_number: u8][name_len: u8][street_len: u8][city_len: u8]
+    //   tail:   [name bytes][street bytes][city bytes]
+    // String<50> defaults to a u8 length prefix because MAX (50) fits in a byte.
     assert_eq!(account.data[0], 1, "discriminator");
     assert_eq!(account.data[1], 42, "house_number");
-
-    let mut offset = 2;
-
-    // name: u8 prefix + "Alice"
-    let name_len = account.data[offset] as usize;
-    offset += 1;
+    let name_len = account.data[2] as usize;
+    let street_len = account.data[3] as usize;
+    let city_len = account.data[4] as usize;
     assert_eq!(name_len, 5);
-    assert_eq!(&account.data[offset..offset + name_len], b"Alice");
-    offset += name_len;
-
-    // street: u8 prefix + "Main Street"
-    let street_len = account.data[offset] as usize;
-    offset += 1;
     assert_eq!(street_len, 11);
-    assert_eq!(&account.data[offset..offset + street_len], b"Main Street");
-    offset += street_len;
-
-    // city: u8 prefix + "New York"
-    let city_len = account.data[offset] as usize;
-    offset += 1;
     assert_eq!(city_len, 8);
-    assert_eq!(&account.data[offset..offset + city_len], b"New York");
+
+    let header_end = 5;
+    assert_eq!(&account.data[header_end..header_end + name_len], b"Alice");
+    let street_start = header_end + name_len;
+    assert_eq!(&account.data[street_start..street_start + street_len], b"Main Street");
+    let city_start = street_start + street_len;
+    assert_eq!(&account.data[city_start..city_start + city_len], b"New York");
 }

basics/close-account/quasar/src/tests.rs

@@ -20,11 +20,15 @@ fn empty(address: Pubkey) -> Account {
     }
 }
 
-/// Build create_user instruction data.
-/// Wire format: [disc=0] [name: u32 prefix + bytes]
+/// Build create_user instruction data using Quasar's compact wire format
+/// (header then tail). `String<50>` defaults to a u8 length prefix.
+///
+///   header: [disc: u8 = 0][name_len: u8]
+///   tail:   [name bytes]
 fn build_create_instruction(name: &str) -> Vec<u8> {
-    let mut data = vec![0u8]; // discriminator = 0
-    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
+    let mut data = Vec::with_capacity(2 + name.len());
+    data.push(0u8); // discriminator
+    data.push(name.len() as u8);
     data.extend_from_slice(name.as_bytes());
     data
 }

basics/favorites/quasar/src/tests.rs

@@ -20,16 +20,20 @@ fn empty(address: Pubkey) -> Account {
     }
 }
 
-/// Build set_favorites instruction data.
-/// Wire format: [disc=0] [ZC: number(u64)] [color: u32 prefix + bytes]
+/// Build set_favorites instruction data using Quasar's compact wire format
+/// (header then tail). `String<50>` defaults to a u8 length prefix.
+///
+///   header: [disc: u8 = 0][number: u64 LE][color_len: u8]
+///   tail:   [color bytes]
 fn build_set_favorites(number: u64, color: &str) -> Vec<u8> {
-    let mut data = vec![0u8]; // discriminator = 0
+    let mut data = Vec::with_capacity(10 + color.len());
 
-    // Fixed ZC args: number (u64, but as Pod it's le bytes)
+    // Header
+    data.push(0u8); // discriminator
     data.extend_from_slice(&number.to_le_bytes());
+    data.push(color.len() as u8);
 
-    // Dynamic String arg: color with u32 prefix
-    data.extend_from_slice(&(color.len() as u32).to_le_bytes());
+    // Tail
     data.extend_from_slice(color.as_bytes());
 
     data

basics/realloc/quasar/src/tests.rs

@@ -20,20 +20,25 @@ fn empty(address: Pubkey) -> Account {
     }
 }
 
-/// Build initialize instruction data.
-/// Wire format: [disc=0] [message: u32 prefix + bytes]
+/// Build initialize instruction data using Quasar's compact wire format.
+/// `String<1024>` defaults to a u8 length prefix (the second `String` generic
+/// argument is the prefix type and its default is `u8`).
+///
+///   header: [disc: u8 = 0][message_len: u8]
+///   tail:   [message bytes]
 fn build_initialize(message: &str) -> Vec<u8> {
-    let mut data = vec![0u8]; // discriminator = 0
-    data.extend_from_slice(&(message.len() as u32).to_le_bytes());
+    let mut data = Vec::with_capacity(2 + message.len());
+    data.push(0u8); // discriminator
+    data.push(message.len() as u8);
     data.extend_from_slice(message.as_bytes());
     data
 }
 
-/// Build update instruction data.
-/// Wire format: [disc=1] [message: u32 prefix + bytes]
+/// Build update instruction data using the same compact wire format.
 fn build_update(message: &str) -> Vec<u8> {
-    let mut data = vec![1u8]; // discriminator = 1
-    data.extend_from_slice(&(message.len() as u32).to_le_bytes());
+    let mut data = Vec::with_capacity(2 + message.len());
+    data.push(1u8); // discriminator
+    data.push(message.len() as u8);
     data.extend_from_slice(message.as_bytes());
     data
 }
@@ -65,14 +70,13 @@ fn test_initialize() {
     let result = svm.process_instruction(&ix, &[signer(payer), empty(message_account)]);
     result.assert_success();
 
-    // Verify: disc(1) + message (u32 prefix "Hello, World!")
+    // Verify: disc(1) + message (u8 prefix + bytes)
     let account = result.account(&message_account).unwrap();
     assert_eq!(account.data[0], 1, "discriminator");
 
-    // Default String uses u32 prefix, max 1024
-    let msg_len = u32::from_le_bytes(account.data[1..5].try_into().unwrap()) as usize;
+    let msg_len = account.data[1] as usize;
     assert_eq!(msg_len, 13);
-    assert_eq!(&account.data[5..5 + msg_len], b"Hello, World!");
+    assert_eq!(&account.data[2..2 + msg_len], b"Hello, World!");
 }
 
 #[test]

basics/rent/quasar/src/tests.rs

@@ -20,18 +20,22 @@ fn empty(address: Pubkey) -> Account {
     }
 }
 
-/// Build create_system_account instruction data (discriminator = 0).
-/// Wire format: [disc=0] [name: String] [address: String]
-/// Both String args are dynamic (u32 length prefix + bytes).
+/// Build create_system_account instruction data using Quasar's compact
+/// wire format (header then tail). `String<50>` defaults to a u8 length
+/// prefix (the second `String` generic argument is the prefix type).
+///
+///   header: [disc: u8 = 0][name_len: u8][address_len: u8]
+///   tail:   [name bytes][address bytes]
 fn build_create_system_account(name: &str, address: &str) -> Vec<u8> {
-    let mut data = vec![0u8]; // discriminator = 0
+    let mut data = Vec::with_capacity(3 + name.len() + address.len());
 
-    // Dynamic String: name
-    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
-    data.extend_from_slice(name.as_bytes());
+    // Header
+    data.push(0u8); // discriminator
+    data.push(name.len() as u8);
+    data.push(address.len() as u8);
 
-    // Dynamic String: address
-    data.extend_from_slice(&(address.len() as u32).to_le_bytes());
+    // Tail
+    data.extend_from_slice(name.as_bytes());
     data.extend_from_slice(address.as_bytes());
 
     data

basics/repository-layout/quasar/src/tests.rs

@@ -10,59 +10,63 @@ fn signer(address: Pubkey) -> Account {
     quasar_svm::token::create_keyed_system_account(&address, 10_000_000_000)
 }
 
-/// Build go_on_ride instruction data (discriminator = 0).
-/// Wire format: [disc=0] [ZC: height(u32), ticket_count(u32)] [name: String] [ride_name: String]
+/// Build go_on_ride instruction data using Quasar's compact wire format
+/// (header then tail). `String<50>` defaults to a u8 length prefix.
+///
+///   header: [disc: u8 = 0][height: u32 LE][ticket_count: u32 LE][name_len: u8][ride_name_len: u8]
+///   tail:   [name bytes][ride_name bytes]
 fn build_go_on_ride(name: &str, height: u32, ticket_count: u32, ride_name: &str) -> Vec<u8> {
-    let mut data = vec![0u8]; // discriminator = 0
+    let mut data = Vec::with_capacity(11 + name.len() + ride_name.len());
 
-    // Fixed ZC fields: height, ticket_count
+    // Header
+    data.push(0u8); // discriminator
     data.extend_from_slice(&height.to_le_bytes());
     data.extend_from_slice(&ticket_count.to_le_bytes());
+    data.push(name.len() as u8);
+    data.push(ride_name.len() as u8);
 
-    // Dynamic String: name
-    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
+    // Tail
     data.extend_from_slice(name.as_bytes());
-
-    // Dynamic String: ride_name
-    data.extend_from_slice(&(ride_name.len() as u32).to_le_bytes());
     data.extend_from_slice(ride_name.as_bytes());
 
     data
 }
 
-/// Build play_game instruction data (discriminator = 1).
-/// Wire format: [disc=1] [ZC: ticket_count(u32)] [name: String] [game_name: String]
+/// Build play_game instruction data using the same compact wire format.
+///
+///   header: [disc: u8 = 1][ticket_count: u32 LE][name_len: u8][game_name_len: u8]
+///   tail:   [name bytes][game_name bytes]
 fn build_play_game(name: &str, ticket_count: u32, game_name: &str) -> Vec<u8> {
-    let mut data = vec![1u8]; // discriminator = 1
+    let mut data = Vec::with_capacity(7 + name.len() + game_name.len());
 
-    // Fixed ZC: ticket_count
+    // Header
+    data.push(1u8); // discriminator
     data.extend_from_slice(&ticket_count.to_le_bytes());
+    data.push(name.len() as u8);
+    data.push(game_name.len() as u8);
 
-    // Dynamic String: name
-    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
+    // Tail
     data.extend_from_slice(name.as_bytes());
-
-    // Dynamic String: game_name
-    data.extend_from_slice(&(game_name.len() as u32).to_le_bytes());
     data.extend_from_slice(game_name.as_bytes());
 
     data
 }
 
-/// Build eat_food instruction data (discriminator = 2).
-/// Wire format: [disc=2] [ZC: ticket_count(u32)] [name: String] [food_stand_name: String]
+/// Build eat_food instruction data using the same compact wire format.
+///
+///   header: [disc: u8 = 2][ticket_count: u32 LE][name_len: u8][food_stand_name_len: u8]
+///   tail:   [name bytes][food_stand_name bytes]
 fn build_eat_food(name: &str, ticket_count: u32, food_stand_name: &str) -> Vec<u8> {
-    let mut data = vec![2u8]; // discriminator = 2
+    let mut data = Vec::with_capacity(7 + name.len() + food_stand_name.len());
 
-    // Fixed ZC: ticket_count
+    // Header
+    data.push(2u8); // discriminator
     data.extend_from_slice(&ticket_count.to_le_bytes());
+    data.push(name.len() as u8);
+    data.push(food_stand_name.len() as u8);
 
-    // Dynamic String: name
-    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
+    // Tail
     data.extend_from_slice(name.as_bytes());
-
-    // Dynamic String: food_stand_name
-    data.extend_from_slice(&(food_stand_name.len() as u32).to_le_bytes());
     data.extend_from_slice(food_stand_name.as_bytes());
 
     data

tokens/pda-mint-authority/quasar/src/tests.rs

@@ -75,16 +75,16 @@ fn test_create_mint() {
     let (mint_pda, _) = Pubkey::find_program_address(&[b"mint"], &crate::ID);
     let token_program = quasar_svm::SPL_TOKEN_PROGRAM_ID;
     let system_program = quasar_svm::system_program::ID;
-    let rent = quasar_svm::solana_sdk_ids::sysvar::rent::ID;
 
     let data = build_create_mint_data(9);
 
+    // Account order matches the `CreateMint` Accounts struct:
+    // payer, mint, token_program, system_program.
     let instruction = Instruction {
         program_id: crate::ID,
         accounts: vec![
             solana_instruction::AccountMeta::new(payer.into(), true),
             solana_instruction::AccountMeta::new(mint_pda.into(), false),
-            solana_instruction::AccountMeta::new_readonly(rent.into(), false),
             solana_instruction::AccountMeta::new_readonly(token_program.into(), false),
             solana_instruction::AccountMeta::new_readonly(system_program.into(), false),
         ],