add integration tests from old branch

svm/tests/example-programs/write-to-account/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "write-to-account"
+version = "2.1.0"
+edition = "2021"
+
+[dependencies]
+solana-program = { path = "../../../../sdk/program", version = "=2.1.0" }
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[workspace]

svm/tests/example-programs/write-to-account/src/lib.rs

@@ -0,0 +1,62 @@
+use solana_program::{
+    account_info::{next_account_info, AccountInfo},
+    entrypoint,
+    entrypoint::ProgramResult,
+    incinerator, msg,
+    program_error::ProgramError,
+    pubkey::Pubkey,
+};
+
+entrypoint!(process_instruction);
+
+fn process_instruction(
+    _program_id: &Pubkey,
+    accounts: &[AccountInfo],
+    data: &[u8],
+) -> ProgramResult {
+    let accounts_iter = &mut accounts.iter();
+    let target_account_info = next_account_info(accounts_iter)?;
+    match data[0] {
+        // print account size
+        0 => {
+            msg!(
+                "account size {}",
+                target_account_info.try_borrow_data()?.len()
+            );
+        }
+        // set account data
+        1 => {
+            let mut account_data = target_account_info.try_borrow_mut_data()?;
+            account_data[0] = 100;
+        }
+        // deallocate account
+        2 => {
+            let incinerator_info = next_account_info(accounts_iter)?;
+            if !incinerator::check_id(incinerator_info.key) {
+                return Err(ProgramError::InvalidAccountData);
+            }
+
+            let mut target_lamports = target_account_info.try_borrow_mut_lamports()?;
+            let mut incinerator_lamports = incinerator_info.try_borrow_mut_lamports()?;
+
+            **incinerator_lamports = incinerator_lamports
+                .checked_add(**target_lamports)
+                .ok_or(ProgramError::ArithmeticOverflow)?;
+
+            **target_lamports = target_lamports
+                .checked_sub(**target_lamports)
+                .ok_or(ProgramError::InsufficientFunds)?;
+        }
+        // reallocate account
+        3 => {
+            let new_size = usize::from_le_bytes(data[1..9].try_into().unwrap());
+            target_account_info.realloc(new_size, false)?;
+        }
+        // bad ixn
+        _ => {
+            return Err(ProgramError::InvalidArgument);
+        }
+    }
+
+    Ok(())
+}