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| 1 | +//! Sub-command definition and dispatch. |
| 2 | +//! |
| 3 | +//! `node` is an ordinary clap sub-command, so clap owns its help, usage lines |
| 4 | +//! and error messages. The one thing clap cannot express is a *default* |
| 5 | +//! sub-command, and the node needs one: the Dockerfile, |
| 6 | +//! lean-quickstart, the hive shim and the devnet skills all invoke the binary as |
| 7 | +//! a bare list of node flags, from before there was anything else to run. That |
| 8 | +//! form keeps working because a missing sub-command is filled in as `node` |
| 9 | +//! before parsing — see [`default_subcommand`]. |
| 10 | +
|
| 11 | +use std::ffi::OsString; |
| 12 | + |
| 13 | +use clap::Parser; |
| 14 | + |
| 15 | +use crate::cli::NodeOptions; |
| 16 | +use crate::version; |
| 17 | + |
| 18 | +/// Tokens that already say what to run, so no default is inserted ahead of |
| 19 | +/// them. `help` is clap's own generated sub-command (`ethlambda help node`). |
| 20 | +const EXPLICIT: &[&str] = &[NODE, "help", "-h", "--help", "-V", "--version"]; |
| 21 | + |
| 22 | +const NODE: &str = "node"; |
| 23 | + |
| 24 | +#[derive(Debug, clap::Parser)] |
| 25 | +#[command( |
| 26 | + name = "ethlambda", |
| 27 | + author = "LambdaClass", |
| 28 | + version = version::CLIENT_VERSION, |
| 29 | + about = "ethlambda consensus client", |
| 30 | + // `--version` used to sit on the node options, so it was accepted after |
| 31 | + // node flags; `ethereum/hive` builds its image that way. Propagating it to |
| 32 | + // the sub-commands keeps those invocations working. |
| 33 | + propagate_version = true |
| 34 | +)] |
| 35 | +struct Cli { |
| 36 | + #[command(subcommand)] |
| 37 | + command: Command, |
| 38 | +} |
| 39 | + |
| 40 | +/// What the command line asked the binary to do. |
| 41 | +#[derive(Debug, clap::Subcommand)] |
| 42 | +pub(crate) enum Command { |
| 43 | + /// Run the consensus node (default when no sub-command is given). |
| 44 | + /// |
| 45 | + /// `ethlambda --genesis ...` and `ethlambda node --genesis ...` are the |
| 46 | + /// same invocation. |
| 47 | + // |
| 48 | + // Deliberately not part of the doc comment above, which clap renders as |
| 49 | + // this sub-command's `long_about`: `display_name` keeps `--version` |
| 50 | + // printing `ethlambda <version>` after node flags, as it did when the node |
| 51 | + // flags were the whole command line. It is still listed and invoked as |
| 52 | + // `node`. |
| 53 | + #[command(display_name = "ethlambda")] |
| 54 | + Node(NodeOptions), |
| 55 | +} |
| 56 | + |
| 57 | +/// Parse the process arguments, exiting the way clap does on a parse error, |
| 58 | +/// `--help` or `--version`. |
| 59 | +pub(crate) fn parse() -> Command { |
| 60 | + try_parse_from(std::env::args_os()).unwrap_or_else(|err| err.exit()) |
| 61 | +} |
| 62 | + |
| 63 | +pub(crate) fn try_parse_from<I>(args: I) -> Result<Command, clap::Error> |
| 64 | +where |
| 65 | + I: IntoIterator, |
| 66 | + I::Item: Into<OsString>, |
| 67 | +{ |
| 68 | + let mut args: Vec<OsString> = args.into_iter().map(Into::into).collect(); |
| 69 | + if let Some(token) = default_subcommand(&args) { |
| 70 | + args.insert(1, token.into()); |
| 71 | + } |
| 72 | + Cli::try_parse_from(args).map(|cli| cli.command) |
| 73 | +} |
| 74 | + |
| 75 | +/// The sub-command to insert, if the arguments do not name one. |
| 76 | +/// |
| 77 | +/// `NodeOptions` declares no positional arguments, so the first token after |
| 78 | +/// the program name is either a flag or a sub-command — a flag *value* never |
| 79 | +/// lands there and is never mistaken for one. A leading flag therefore means |
| 80 | +/// the flat node form, and gets `node` inserted ahead of it; a bare invocation |
| 81 | +/// is left alone so clap prints its own "requires a subcommand" help. |
| 82 | +fn default_subcommand(args: &[OsString]) -> Option<&'static str> { |
| 83 | + let first = args.get(1)?.to_str()?; |
| 84 | + (!EXPLICIT.contains(&first)).then_some(NODE) |
| 85 | +} |
| 86 | + |
| 87 | +#[cfg(test)] |
| 88 | +mod tests { |
| 89 | + use std::path::PathBuf; |
| 90 | + |
| 91 | + use clap::error::ErrorKind; |
| 92 | + |
| 93 | + use super::*; |
| 94 | + |
| 95 | + /// The flat invocation shape used by the Dockerfile, lean-quickstart, the |
| 96 | + /// hive shim and the devnet skills. It must keep parsing unchanged. |
| 97 | + const FLAT: &[&str] = &[ |
| 98 | + "ethlambda", |
| 99 | + "--genesis", |
| 100 | + "config.yaml", |
| 101 | + "--validators", |
| 102 | + "annotated_validators.yaml", |
| 103 | + "--bootnodes", |
| 104 | + "nodes.yaml", |
| 105 | + "--validator-config", |
| 106 | + "validator-config.yaml", |
| 107 | + "--hash-sig-keys-dir", |
| 108 | + "hash-sig-keys/", |
| 109 | + "--node-key", |
| 110 | + "node.key", |
| 111 | + "--node-id", |
| 112 | + "ethlambda_0", |
| 113 | + "--gossipsub-port", |
| 114 | + "9001", |
| 115 | + "--is-aggregator", |
| 116 | + ]; |
| 117 | + |
| 118 | + /// `FLAT` with an explicit `node` sub-command token. |
| 119 | + fn with_node_token() -> Vec<&'static str> { |
| 120 | + let mut args = vec!["ethlambda", NODE]; |
| 121 | + args.extend_from_slice(&FLAT[1..]); |
| 122 | + args |
| 123 | + } |
| 124 | + |
| 125 | + fn node_options(args: &[&str]) -> NodeOptions { |
| 126 | + let Command::Node(options) = |
| 127 | + try_parse_from(args.iter().map(OsString::from)).expect("invocation parses"); |
| 128 | + options |
| 129 | + } |
| 130 | + |
| 131 | + #[test] |
| 132 | + fn flat_invocation_parses_unchanged() { |
| 133 | + let options = node_options(FLAT); |
| 134 | + assert_eq!(options.genesis, PathBuf::from("config.yaml")); |
| 135 | + assert_eq!(options.hash_sig_keys_dir, PathBuf::from("hash-sig-keys/")); |
| 136 | + assert_eq!(options.node_id, "ethlambda_0"); |
| 137 | + assert_eq!(options.gossipsub_port, 9001); |
| 138 | + assert!(options.is_aggregator); |
| 139 | + } |
| 140 | + |
| 141 | + #[test] |
| 142 | + fn node_sub_command_accepts_the_same_flags_as_the_flat_form() { |
| 143 | + let flat = node_options(FLAT); |
| 144 | + let scoped = node_options(&with_node_token()); |
| 145 | + // Compared through `Debug`, which the derive prints field by field, |
| 146 | + // because `NodeOptions` derives no `PartialEq` — and deriving one for |
| 147 | + // a test would touch the parser this module deliberately leaves alone. |
| 148 | + assert_eq!(format!("{flat:?}"), format!("{scoped:?}")); |
| 149 | + } |
| 150 | + |
| 151 | + #[test] |
| 152 | + fn a_flag_value_of_node_is_not_taken_for_the_sub_command() { |
| 153 | + let mut args: Vec<&str> = FLAT.to_vec(); |
| 154 | + let value = args |
| 155 | + .iter() |
| 156 | + .position(|arg| *arg == "ethlambda_0") |
| 157 | + .expect("node id value present"); |
| 158 | + args[value] = NODE; |
| 159 | + assert_eq!(node_options(&args).node_id, NODE); |
| 160 | + } |
| 161 | + |
| 162 | + #[test] |
| 163 | + fn a_node_token_after_the_flags_is_still_rejected() { |
| 164 | + // The default is inserted at the front or not at all, so a later token |
| 165 | + // stays the stray positional argument it has always been. |
| 166 | + let mut args: Vec<&str> = FLAT.to_vec(); |
| 167 | + args.push(NODE); |
| 168 | + let err = try_parse_from(args.iter().map(OsString::from)) |
| 169 | + .expect_err("a trailing token must not be swallowed"); |
| 170 | + assert_eq!(err.kind(), ErrorKind::UnknownArgument); |
| 171 | + } |
| 172 | + |
| 173 | + #[test] |
| 174 | + fn a_second_node_token_is_rejected_by_clap() { |
| 175 | + let mut args = with_node_token(); |
| 176 | + args.insert(1, NODE); |
| 177 | + let err = try_parse_from(args.iter().map(OsString::from)) |
| 178 | + .expect_err("only one sub-command is accepted"); |
| 179 | + assert_eq!(err.kind(), ErrorKind::UnknownArgument); |
| 180 | + } |
| 181 | + |
| 182 | + #[test] |
| 183 | + fn missing_required_flag_keeps_the_clap_error_in_both_forms() { |
| 184 | + // `--genesis config.yaml` dropped from the front of the flag list. |
| 185 | + let flat: Vec<&str> = std::iter::once("ethlambda") |
| 186 | + .chain(FLAT[3..].iter().copied()) |
| 187 | + .collect(); |
| 188 | + let mut scoped = vec!["ethlambda", NODE]; |
| 189 | + scoped.extend_from_slice(&flat[1..]); |
| 190 | + |
| 191 | + for args in [flat, scoped] { |
| 192 | + let err = try_parse_from(args.iter().map(OsString::from)) |
| 193 | + .expect_err("a missing required flag must error"); |
| 194 | + assert_eq!(err.kind(), ErrorKind::MissingRequiredArgument); |
| 195 | + } |
| 196 | + } |
| 197 | + |
| 198 | + #[test] |
| 199 | + fn bare_invocation_asks_for_a_sub_command() { |
| 200 | + // Nothing to default: clap prints the top-level help, which lists the |
| 201 | + // sub-commands, rather than a missing-argument list for one of them. |
| 202 | + let err = try_parse_from(["ethlambda"].iter().map(OsString::from)) |
| 203 | + .expect_err("an argument-less invocation must not start a node"); |
| 204 | + assert_eq!( |
| 205 | + err.kind(), |
| 206 | + ErrorKind::DisplayHelpOnMissingArgumentOrSubcommand |
| 207 | + ); |
| 208 | + assert_ne!(err.exit_code(), 0, "a bare invocation must not exit 0"); |
| 209 | + } |
| 210 | + |
| 211 | + #[test] |
| 212 | + fn help_and_version_stay_top_level_flags() { |
| 213 | + // `ethereum/hive` builds its ethlambda image by piping |
| 214 | + // `ethlambda --version` into a file, with and without flags in front. |
| 215 | + let mut version_after_flags: Vec<&str> = FLAT.to_vec(); |
| 216 | + version_after_flags.push("--version"); |
| 217 | + |
| 218 | + for (args, expected) in [ |
| 219 | + (vec!["ethlambda", "--help"], ErrorKind::DisplayHelp), |
| 220 | + (vec!["ethlambda", "--version"], ErrorKind::DisplayVersion), |
| 221 | + (version_after_flags, ErrorKind::DisplayVersion), |
| 222 | + ] { |
| 223 | + let err = try_parse_from(args.iter().map(OsString::from)) |
| 224 | + .expect_err("help and version short-circuit parsing"); |
| 225 | + assert_eq!(err.kind(), expected); |
| 226 | + } |
| 227 | + } |
| 228 | + |
| 229 | + #[test] |
| 230 | + fn version_output_is_identical_for_every_form() { |
| 231 | + // `--version` moved from the node options to the top-level command, so |
| 232 | + // pin that it still prints one string: `ethereum/hive` records this |
| 233 | + // output as the client version. |
| 234 | + let mut after_flags: Vec<&str> = FLAT.to_vec(); |
| 235 | + after_flags.push("--version"); |
| 236 | + let printed: Vec<String> = [ |
| 237 | + vec!["ethlambda", "--version"], |
| 238 | + vec!["ethlambda", NODE, "--version"], |
| 239 | + after_flags, |
| 240 | + ] |
| 241 | + .into_iter() |
| 242 | + .map(|args| { |
| 243 | + try_parse_from(args.iter().map(OsString::from)) |
| 244 | + .expect_err("--version short-circuits parsing") |
| 245 | + .to_string() |
| 246 | + }) |
| 247 | + .collect(); |
| 248 | + assert_eq!(printed[0], printed[1]); |
| 249 | + assert_eq!(printed[0], printed[2]); |
| 250 | + } |
| 251 | + |
| 252 | + #[test] |
| 253 | + fn help_lists_the_sub_commands() { |
| 254 | + // Listed by clap itself, because they are real sub-commands. |
| 255 | + let err = try_parse_from(["ethlambda", "--help"].iter().map(OsString::from)) |
| 256 | + .expect_err("--help short-circuits parsing"); |
| 257 | + assert!(err.to_string().contains(NODE), "{err}"); |
| 258 | + } |
| 259 | +} |
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