| 1 | //! Compact summaries for Cargo failures. |
| 2 | //! |
| 3 | //! Cargo output can be large and noisy. This module extracts stable failure |
| 4 | //! signals for tool metadata so context compaction can preserve the actionable |
| 5 | //! lines without re-running `cargo test | tail`. |
| 6 | |
| 7 | use serde::{Deserialize, Serialize}; |
| 8 | use serde_json::{Value, json}; |
| 9 | |
| 10 | const MAX_ITEMS: usize = 8; |
| 11 | const MAX_SUMMARY_CHARS: usize = 1_200; |
| 12 | |
| 13 | #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)] |
| 14 | #[serde(rename_all = "snake_case")] |
| 15 | pub(crate) enum CargoFailureKind { |
| 16 | TestFailure, |
| 17 | CompileError, |
| 18 | CargoFailure, |
| 19 | } |
| 20 | |
| 21 | impl CargoFailureKind { |
| 22 | fn label(&self) -> &'static str { |
| 23 | match self { |
| 24 | Self::TestFailure => "test_failure", |
| 25 | Self::CompileError => "compile_error", |
| 26 | Self::CargoFailure => "cargo_failure", |
| 27 | } |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)] |
| 32 | pub(crate) struct CargoFailureSummary { |
| 33 | pub(crate) kind: CargoFailureKind, |
| 34 | pub(crate) summary: String, |
| 35 | #[serde(default, skip_serializing_if = "Vec::is_empty")] |
| 36 | pub(crate) failing_tests: Vec<String>, |
| 37 | #[serde(default, skip_serializing_if = "Vec::is_empty")] |
| 38 | pub(crate) error_codes: Vec<String>, |
| 39 | #[serde(default, skip_serializing_if = "Vec::is_empty")] |
| 40 | pub(crate) primary_errors: Vec<String>, |
| 41 | #[serde(default, skip_serializing_if = "Vec::is_empty")] |
| 42 | pub(crate) panic_locations: Vec<String>, |
| 43 | #[serde(default, skip_serializing_if = "Option::is_none")] |
| 44 | pub(crate) test_result: Option<String>, |
| 45 | #[serde(default, skip_serializing_if = "Option::is_none")] |
| 46 | pub(crate) final_error: Option<String>, |
| 47 | } |
| 48 | |
| 49 | impl CargoFailureSummary { |
| 50 | pub(crate) fn to_metadata_value(&self) -> Value { |
| 51 | json!(self) |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | pub(crate) fn summarize_cargo_failure( |
| 56 | command: &str, |
| 57 | stdout: &str, |
| 58 | stderr: &str, |
| 59 | exit_code: Option<i32>, |
| 60 | ) -> Option<CargoFailureSummary> { |
| 61 | if exit_code == Some(0) || !looks_like_cargo_command(command) { |
| 62 | return None; |
| 63 | } |
| 64 | |
| 65 | let mut failing_tests = Vec::new(); |
| 66 | let mut error_codes = Vec::new(); |
| 67 | let mut primary_errors = Vec::new(); |
| 68 | let mut panic_locations = Vec::new(); |
| 69 | let mut test_result = None; |
| 70 | let mut final_error = None; |
| 71 | |
| 72 | for line in stderr.lines().chain(stdout.lines()) { |
| 73 | let trimmed = line.trim(); |
| 74 | if trimmed.is_empty() { |
| 75 | continue; |
| 76 | } |
| 77 | |
| 78 | if let Some(test) = parse_failed_test_line(trimmed) { |
| 79 | push_unique_limited(&mut failing_tests, test); |
| 80 | } |
| 81 | if let Some(test) = parse_failure_header(trimmed) { |
| 82 | push_unique_limited(&mut failing_tests, test); |
| 83 | } |
| 84 | if let Some(code) = parse_error_code(trimmed) { |
| 85 | push_unique_limited(&mut error_codes, code); |
| 86 | } |
| 87 | if is_primary_error_line(trimmed) { |
| 88 | push_unique_limited(&mut primary_errors, trimmed.to_string()); |
| 89 | } |
| 90 | if trimmed.contains("panicked at ") { |
| 91 | push_unique_limited(&mut panic_locations, trimmed.to_string()); |
| 92 | } |
| 93 | if trimmed.starts_with("test result:") { |
| 94 | test_result = Some(trimmed.to_string()); |
| 95 | } |
| 96 | if trimmed.starts_with("error: could not compile") |
| 97 | || trimmed.starts_with("error: aborting due to") |
| 98 | || trimmed.starts_with("error: test failed") |
| 99 | { |
| 100 | final_error = Some(trimmed.to_string()); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | let kind = classify_failure(&failing_tests, &primary_errors, test_result.as_deref()); |
| 105 | if !has_actionable_signal( |
| 106 | &failing_tests, |
| 107 | &error_codes, |
| 108 | &primary_errors, |
| 109 | &panic_locations, |
| 110 | test_result.as_deref(), |
| 111 | final_error.as_deref(), |
| 112 | ) { |
| 113 | return None; |
| 114 | } |
| 115 | let summary = build_summary( |
| 116 | &kind, |
| 117 | &failing_tests, |
| 118 | &error_codes, |
| 119 | &primary_errors, |
| 120 | &panic_locations, |
| 121 | test_result.as_deref(), |
| 122 | final_error.as_deref(), |
| 123 | ); |
| 124 | |
| 125 | Some(CargoFailureSummary { |
| 126 | kind, |
| 127 | summary, |
| 128 | failing_tests, |
| 129 | error_codes, |
| 130 | primary_errors, |
| 131 | panic_locations, |
| 132 | test_result, |
| 133 | final_error, |
| 134 | }) |
| 135 | } |
| 136 | |
| 137 | fn looks_like_cargo_command(command: &str) -> bool { |
| 138 | let Some(tokens) = shlex::split(command) else { |
| 139 | return false; |
| 140 | }; |
| 141 | |
| 142 | let mut expect_command = true; |
| 143 | for (idx, raw_token) in tokens.iter().enumerate() { |
| 144 | let token = normalize_shell_token(raw_token); |
| 145 | if token.is_empty() { |
| 146 | continue; |
| 147 | } |
| 148 | if is_shell_separator(token) { |
| 149 | expect_command = true; |
| 150 | continue; |
| 151 | } |
| 152 | if !expect_command { |
| 153 | continue; |
| 154 | } |
| 155 | if looks_like_env_assignment(token) { |
| 156 | continue; |
| 157 | } |
| 158 | if is_cargo_binary(token) { |
| 159 | return cargo_subcommand(&tokens[idx + 1..]).is_some(); |
| 160 | } |
| 161 | expect_command = false; |
| 162 | } |
| 163 | |
| 164 | false |
| 165 | } |
| 166 | |
| 167 | fn parse_failed_test_line(line: &str) -> Option<String> { |
| 168 | let rest = line.strip_prefix("test ")?; |
| 169 | let (name, status) = rest.rsplit_once(" ... ")?; |
| 170 | (status == "FAILED").then(|| name.trim().to_string()) |
| 171 | } |
| 172 | |
| 173 | fn parse_failure_header(line: &str) -> Option<String> { |
| 174 | let rest = line.strip_prefix("---- ")?; |
| 175 | let name = rest.strip_suffix(" stdout ----")?; |
| 176 | Some(name.trim().to_string()) |
| 177 | } |
| 178 | |
| 179 | fn parse_error_code(line: &str) -> Option<String> { |
| 180 | let rest = line.strip_prefix("error[")?; |
| 181 | let (code, _) = rest.split_once("]")?; |
| 182 | Some(code.to_string()) |
| 183 | } |
| 184 | |
| 185 | fn is_primary_error_line(line: &str) -> bool { |
| 186 | line.starts_with("error[") |
| 187 | || (line.starts_with("error:") && !line.starts_with("error: test failed")) |
| 188 | } |
| 189 | |
| 190 | fn classify_failure( |
| 191 | failing_tests: &[String], |
| 192 | primary_errors: &[String], |
| 193 | test_result: Option<&str>, |
| 194 | ) -> CargoFailureKind { |
| 195 | if !failing_tests.is_empty() |
| 196 | || test_result.is_some_and(|line| line.to_ascii_lowercase().contains("failed")) |
| 197 | { |
| 198 | CargoFailureKind::TestFailure |
| 199 | } else if !primary_errors.is_empty() { |
| 200 | CargoFailureKind::CompileError |
| 201 | } else { |
| 202 | CargoFailureKind::CargoFailure |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | fn has_actionable_signal( |
| 207 | failing_tests: &[String], |
| 208 | error_codes: &[String], |
| 209 | primary_errors: &[String], |
| 210 | panic_locations: &[String], |
| 211 | test_result: Option<&str>, |
| 212 | final_error: Option<&str>, |
| 213 | ) -> bool { |
| 214 | !failing_tests.is_empty() |
| 215 | || !error_codes.is_empty() |
| 216 | || !primary_errors.is_empty() |
| 217 | || !panic_locations.is_empty() |
| 218 | || test_result.is_some() |
| 219 | || final_error.is_some() |
| 220 | } |
| 221 | |
| 222 | fn build_summary( |
| 223 | kind: &CargoFailureKind, |
| 224 | failing_tests: &[String], |
| 225 | error_codes: &[String], |
| 226 | primary_errors: &[String], |
| 227 | panic_locations: &[String], |
| 228 | test_result: Option<&str>, |
| 229 | final_error: Option<&str>, |
| 230 | ) -> String { |
| 231 | let mut lines = Vec::new(); |
| 232 | lines.push(format!("Cargo failure kind: {}.", kind.label())); |
| 233 | if !failing_tests.is_empty() { |
| 234 | lines.push(format!("Failing tests: {}.", failing_tests.join(", "))); |
| 235 | } |
| 236 | if !error_codes.is_empty() { |
| 237 | lines.push(format!("Rust error codes: {}.", error_codes.join(", "))); |
| 238 | } |
| 239 | if let Some(line) = primary_errors.first() { |
| 240 | lines.push(format!("Primary error: {line}")); |
| 241 | } |
| 242 | if let Some(line) = panic_locations.first() { |
| 243 | lines.push(format!("Panic: {line}")); |
| 244 | } |
| 245 | if let Some(line) = test_result { |
| 246 | lines.push(line.to_string()); |
| 247 | } |
| 248 | if let Some(line) = final_error { |
| 249 | lines.push(line.to_string()); |
| 250 | } |
| 251 | truncate_chars(&lines.join("\n"), MAX_SUMMARY_CHARS) |
| 252 | } |
| 253 | |
| 254 | fn normalize_shell_token(token: &str) -> &str { |
| 255 | token.trim_matches(|ch| matches!(ch, '(' | ')' | '{' | '}')) |
| 256 | } |
| 257 | |
| 258 | fn is_shell_separator(token: &str) -> bool { |
| 259 | matches!(token, "&&" | "||" | ";" | "|") |
| 260 | } |
| 261 | |
| 262 | fn looks_like_env_assignment(token: &str) -> bool { |
| 263 | let Some((name, _)) = token.split_once('=') else { |
| 264 | return false; |
| 265 | }; |
| 266 | !name.is_empty() |
| 267 | && name |
| 268 | .bytes() |
| 269 | .all(|byte| byte == b'_' || byte.is_ascii_alphanumeric()) |
| 270 | && !name.as_bytes()[0].is_ascii_digit() |
| 271 | } |
| 272 | |
| 273 | fn is_cargo_binary(token: &str) -> bool { |
| 274 | let name = token.rsplit(['/', '\\']).next().unwrap_or(token); |
| 275 | name.eq_ignore_ascii_case("cargo") || name.eq_ignore_ascii_case("cargo.exe") |
| 276 | } |
| 277 | |
| 278 | fn cargo_subcommand(tokens: &[String]) -> Option<&str> { |
| 279 | let mut idx = 0; |
| 280 | while let Some(raw_token) = tokens.get(idx) { |
| 281 | let token = normalize_shell_token(raw_token); |
| 282 | if token.is_empty() { |
| 283 | idx += 1; |
| 284 | continue; |
| 285 | } |
| 286 | if is_shell_separator(token) { |
| 287 | return None; |
| 288 | } |
| 289 | if token.starts_with('+') { |
| 290 | idx += 1; |
| 291 | continue; |
| 292 | } |
| 293 | if token.starts_with('-') { |
| 294 | if cargo_global_flag_takes_value(token) { |
| 295 | idx += 2; |
| 296 | } else { |
| 297 | idx += 1; |
| 298 | } |
| 299 | continue; |
| 300 | } |
| 301 | return is_supported_cargo_subcommand(token).then_some(token); |
| 302 | } |
| 303 | None |
| 304 | } |
| 305 | |
| 306 | fn cargo_global_flag_takes_value(token: &str) -> bool { |
| 307 | if token.contains('=') { |
| 308 | return false; |
| 309 | } |
| 310 | matches!( |
| 311 | token, |
| 312 | "--color" |
| 313 | | "--config" |
| 314 | | "-C" |
| 315 | | "--jobs" |
| 316 | | "-j" |
| 317 | | "--lockfile-path" |
| 318 | | "--manifest-path" |
| 319 | | "--message-format" |
| 320 | | "--package" |
| 321 | | "-p" |
| 322 | | "--target" |
| 323 | | "--target-dir" |
| 324 | | "-Z" |
| 325 | ) |
| 326 | } |
| 327 | |
| 328 | fn is_supported_cargo_subcommand(token: &str) -> bool { |
| 329 | matches!( |
| 330 | token, |
| 331 | "test" | "check" | "build" | "clippy" | "run" | "t" | "c" | "b" | "r" |
| 332 | ) |
| 333 | } |
| 334 | |
| 335 | fn push_unique_limited(target: &mut Vec<String>, value: String) { |
| 336 | if target.len() >= MAX_ITEMS || target.iter().any(|existing| existing == &value) { |
| 337 | return; |
| 338 | } |
| 339 | target.push(value); |
| 340 | } |
| 341 | |
| 342 | fn truncate_chars(text: &str, max_chars: usize) -> String { |
| 343 | if let Some((idx, _)) = text.char_indices().nth(max_chars) { |
| 344 | if max_chars < 3 { |
| 345 | return text[..idx].to_string(); |
| 346 | } |
| 347 | let truncate_at = text |
| 348 | .char_indices() |
| 349 | .nth(max_chars - 3) |
| 350 | .map(|(idx, _)| idx) |
| 351 | .unwrap_or(0); |
| 352 | format!("{}...", &text[..truncate_at]) |
| 353 | } else { |
| 354 | text.to_string() |
| 355 | } |
| 356 | } |
| 357 | |
| 358 | #[cfg(test)] |
| 359 | mod tests { |
| 360 | use super::*; |
| 361 | |
| 362 | #[test] |
| 363 | fn summarizes_failed_libtest_output() { |
| 364 | let stdout = r" |
| 365 | running 1 test |
| 366 | test tests::fails ... FAILED |
| 367 | |
| 368 | failures: |
| 369 | |
| 370 | ---- tests::fails stdout ---- |
| 371 | thread 'tests::fails' panicked at src/lib.rs:7:9: |
| 372 | assertion `left == right` failed |
| 373 | |
| 374 | test result: FAILED. 0 passed; 1 failed; 0 ignored; finished in 0.00s |
| 375 | "; |
| 376 | let summary = |
| 377 | summarize_cargo_failure("cargo test", stdout, "", Some(101)).expect("summary"); |
| 378 | |
| 379 | assert_eq!(summary.kind, CargoFailureKind::TestFailure); |
| 380 | assert_eq!(summary.failing_tests, vec!["tests::fails"]); |
| 381 | assert!(summary.summary.contains("Failing tests: tests::fails")); |
| 382 | assert!(summary.test_result.unwrap().contains("1 failed")); |
| 383 | } |
| 384 | |
| 385 | #[test] |
| 386 | fn summarizes_rustc_compile_error() { |
| 387 | let stderr = r#" |
| 388 | error[E0308]: mismatched types |
| 389 | --> src/lib.rs:2:5 |
| 390 | | |
| 391 | 2 | "" |
| 392 | | ^^ expected `i32`, found `&str` |
| 393 | error: could not compile `demo` (lib) due to 1 previous error |
| 394 | "#; |
| 395 | let summary = |
| 396 | summarize_cargo_failure("cargo check", "", stderr, Some(101)).expect("summary"); |
| 397 | |
| 398 | assert_eq!(summary.kind, CargoFailureKind::CompileError); |
| 399 | assert_eq!(summary.error_codes, vec!["E0308"]); |
| 400 | assert!(summary.primary_errors[0].contains("mismatched types")); |
| 401 | assert!(summary.final_error.unwrap().contains("could not compile")); |
| 402 | } |
| 403 | |
| 404 | #[test] |
| 405 | fn recognizes_cargo_aliases_and_uncoded_errors() { |
| 406 | let stderr = "error: cannot find value `missing` in this scope\n"; |
| 407 | let summary = summarize_cargo_failure("cargo c", "", stderr, Some(101)).expect("summary"); |
| 408 | |
| 409 | assert_eq!(summary.kind, CargoFailureKind::CompileError); |
| 410 | assert_eq!( |
| 411 | summary.primary_errors, |
| 412 | vec!["error: cannot find value `missing` in this scope"] |
| 413 | ); |
| 414 | } |
| 415 | |
| 416 | #[test] |
| 417 | fn recognizes_tokenized_cargo_invocations() { |
| 418 | assert!( |
| 419 | summarize_cargo_failure( |
| 420 | "cargo +nightly --manifest-path demo/Cargo.toml test", |
| 421 | "test tests::fails ... FAILED\n", |
| 422 | "", |
| 423 | Some(101), |
| 424 | ) |
| 425 | .is_some() |
| 426 | ); |
| 427 | assert!( |
| 428 | summarize_cargo_failure( |
| 429 | "DEMO=1 cargo --locked run", |
| 430 | "", |
| 431 | "error: process didn't exit successfully\n", |
| 432 | Some(101), |
| 433 | ) |
| 434 | .is_some() |
| 435 | ); |
| 436 | assert!( |
| 437 | summarize_cargo_failure( |
| 438 | "echo cargo test && false", |
| 439 | "test tests::fails ... FAILED\n", |
| 440 | "", |
| 441 | Some(1), |
| 442 | ) |
| 443 | .is_none() |
| 444 | ); |
| 445 | } |
| 446 | |
| 447 | #[test] |
| 448 | fn skips_generic_cargo_failure_without_actionable_signal() { |
| 449 | assert!( |
| 450 | summarize_cargo_failure("cargo test", "build failed", "command failed", Some(1)) |
| 451 | .is_none() |
| 452 | ); |
| 453 | } |
| 454 | |
| 455 | #[test] |
| 456 | fn truncate_chars_respects_tiny_limits() { |
| 457 | assert_eq!(truncate_chars("abcdef", 0), ""); |
| 458 | assert_eq!(truncate_chars("abcdef", 1), "a"); |
| 459 | assert_eq!(truncate_chars("abcdef", 2), "ab"); |
| 460 | assert_eq!(truncate_chars("abcdef", 3), "..."); |
| 461 | assert_eq!(truncate_chars("abcdef", 4), "a..."); |
| 462 | } |
| 463 | |
| 464 | #[test] |
| 465 | fn ignores_successful_or_non_cargo_commands() { |
| 466 | assert!(summarize_cargo_failure("cargo test", "", "", Some(0)).is_none()); |
| 467 | assert!(summarize_cargo_failure("npm test", "failed", "", Some(1)).is_none()); |
| 468 | } |
| 469 | } |
| 470 |