Solana CPI Example — Tests and Build Notes

This repository contains two example Solana programs (caller and called) and two corresponding tests:

• a ProgramTest-based test that runs in-process (cross_program_invocation_program_test), and
• a validator-based test that uses a running local validator and deployed programs (cross_program_invocation_validator_test).

Important: Tests must now be run separately! There’s no point in running all tests together (e.g., cargo test -- --nocapture), because the ProgramTest-based test relies on .so binaries without an entrypoint, while the validator-based test requires .so files with an entrypoint. Therefore, each test must be built and run separately, with its own dedicated build.

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Validator-Based Test

1. Build the Contracts

First, build both contracts:

cargo build-sbf --manifest-path=code/caller/Cargo.toml
cargo build-sbf --manifest-path=code/called/Cargo.toml

Important: The --features disable-entrypoint flag must not be used for validator-based tests.

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2. Start the Local Validator

Launch a local Solana test validator:

solana-test-validator

See snippets.md for an advanced validator launch command that helps avoid WSL-related issues.

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3. Deploy the Contracts

Deploy both contracts to the local validator:

solana program deploy target/deploy/called.so
solana program deploy target/deploy/caller.so

Important: After deployment, update the pubkey variables for the smart contracts in the tests with the actual addresses returned by the deploy commands.

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4. Run the Test

Run the validator-based test:

cargo test -p tests cross_program_invocation_validator_test -- --nocapture

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ProgramTest-Based Test

1. Build the Contracts

First, build both contracts:

cargo build-sbf --manifest-path=code/caller/Cargo.toml --features disable-entrypoint
cargo build-sbf --manifest-path=code/called/Cargo.toml --features disable-entrypoint

Important: The --features disable-entrypoint flag is required for ProgramTest-based tests.

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2. Run the Test

Run the ProgramTest-based test:

cargo test -p tests cross_program_invocation_program_test -- --nocapture

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All useful command shortcuts are stored in snippets.md.