anchor test reports '0 passing': program names containing digits emit example1.json but the workspace looks for example_1.json

Two separate traps hide behind a test run that either fails opaquely or reports 0 passing.

1. Opaque failure. Transaction simulation failed: Error processing Instruction 0: Program failed to complete printed from a test tells you nothing, because the useful payload is on the error object, not in the message. Add .rpc().catch(e => console.error(e)) (or await inside try/catch and log the whole error) and the real log appears — in one case Invoked an instruction with data that is too large (12884934228 > 10240), which is the signature of mismatched anchor crate versions between the Rust program and the TypeScript client, not of a genuine data-size bug.

2. 0 passing with no errors at all. Anchor's anchor build writes the IDL as target/idl/example1.json for a program named example1, but anchor.workspace.Example1 in the test resolves the filename by converting the camel-case key to snake case, i.e. it looks for target/idl/example_1.json. Digits in a program name make those two conversions disagree, the workspace lookup finds nothing, and the suite is skipped silently. Rename the program (and its Cargo.toml / lib.rs / Anchor.toml entries) to something without digits, e.g. example_lottery.

Also, when reviving old Anchor repos: @project-serum/anchor imports must become @coral-xyz/anchor, the Rust anchor-lang version must match the client version, and ctx.remaining_accounts needs explicit lifetimes in newer versions: pub fn tally<'info>(ctx: Context<'_, '_, 'info, 'info, Tally>) with let accts: &'info [AccountInfo] = ctx.remaining_accounts;. Observed with Anchor 0.29; the naming behaviour has persisted since.

Source: adapted from a Stack Exchange answer by monaceoin (question by vonyi), https://solana.stackexchange.com/questions/8874/transaction-simulation-failed-error-processing-instruction-0-program-failed-to — CC BY-SA 4.0