Debugging Solana Programs
There are a number of options and supporting tools for testing and debugging a Solana program.
- The crate
solana-program-testenables use of bare bones local runtime where you can test and debug your program interactively (e.g. in vscode).
- The crate
solana-validatorenables use of the
solana-test-validatorimplementation for more robust testing that occurs on a local validator node. You can run from the editor but breakpoints in the program are ignored.
- The CLI tool
- For all the above, liberal use of
msg!macro in your program is recommended at the start and then removing them as you test and ensure rock solid behavior. Remember that
msg!consumes Compute Units which can eventually fail your program by hitting the Compute Unit budget caps.
The steps in the following sections use the solana-program-bpf-template. Clone that to your machine:
git clone firstname.lastname@example.org:mvines/solana-bpf-program-template.git cd solana-bpf-program-template code .
Runtime Testing and Debugging in editor
Open the file
You'll see that the program is a pretty simple and basically just logs the content received by the program entrypoint function:
- Go to the
#[cfg(test)]section and click
Run Tests. This will build the program and then execute the
async fn test_transaction()test. You will see the log messages (simplified) in the vscode terminal below the source.
running 1 test "bpf_program_template" program loaded as native code Program 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM invoke  Program log: process_instruction: 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM: 1 accounts, data=[1, 2, 3] Program 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM success test test::test_transaction ... ok test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 33.41s
- Set a breakpoint on the programs
- Back in the test module, click
Debugand within seconds the debugger will stop on the breakpoint and now you can examine data, step through functions, etc., etc..
These tests are also run from the command line with:
cargo test or
cargo test-bpf. Of course any breakpoints will be ignored.
How groovy can you get!
Keep in mind you are not using a validator node so default programs, blockhashes, etc. are not represented or will not behave as they would when running in validator node. This is why the gang at Solana gave us Local Validator Node testing!
Local Validator Node Testing in editor
Integration testing using programmatic loading of a local validator node is defined in the
By default, the template repo integration tests will only be runnable from the command line using
cargo test-bpf. The following steps will enable you to run within the editor as well as displaying program validator logs and
msg! outputs from your program:
- In the repo directory run
cargo build-bpfto build the sample program
- In the editor, open
- Comment out line 1 ->
// #![cfg(feature = "test-bpf")]
- On line 19 change it to read:
- Insert the following at line 22
Run Testabove the
This will load the validator node then allowing you to construct a transaction (the Rust way) and submit to the node using the
The program's output will also print out in the editor terminal. For example (simplified):
running 1 test Waiting for fees to stabilize 1... Waiting for fees to stabilize 2... Program 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM invoke  Program log: process_instruction: 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM: 1 accounts, data=[1, 2, 3] Program 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM consumed 13027 of 200000 compute units Program 4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM success test test_validator_transaction ... ok test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 6.40s
Debugging here will allow you to debug the functions and methods used in the test body but will not breakpoint in your program.
The bee's knees eh?
Local Validator Node Testing from Client Apps
Lastly, you can start a local validating node and load your program and any accounts using the
solana-test-validator from the command line.
solana-test-validator --help for more details and options. For the example program here is vanilla setup:
- Open a terminal in the repo folder
solana config set -ulto set the configuration to point to local
solana-test-validator --bpf-program target/deploy/bpf_program_template-keypair.json target/deploy/bpf_program_template.so
- Open another terminal and run
solana logsto start the log streamer
- You can then run your client program and observe program output in the terminal where you started the log streamer
Now that is the cat's pajamas YO!