1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364
//!
//! Copyright 2017 Metaswitch Networks
//!
//! Helper functions for use when testing slog logs.
//!
//! This module is a grab-bag of tools that have been found useful when testing slog logs.
//! A typical test will create a new `iobuffer::IoBuffer`, pass it to `new_test_logger` to
//! construct a logger, and pass that logger to the system under test. It will then exercise
//! the system. Finally, it will use `logs_in_range` to extract the logs it is interested in
//! in a canonical order, and test that they are as expected using standard Rust tools.
//!
//! # Example
//! ```
//! use slog::debug;
//! use slog_extlog::slog_test;
//!
//! // Setup code
//! let mut data = iobuffer::IoBuffer::new();
//! let logger = slog_test::new_test_logger(data.clone());
//!
//! // Application code
//! debug!(logger, "Something happened to it";
//! "subject" => "something",
//! "verb" => "happened",
//! "object" => "it");
//!
//! // Test code - parse all logs and check their contents.
//! let logs = slog_test::read_json_values(&mut data);
//! slog_test::assert_json_matches(&logs[0], &serde_json::json!({ "subject": "something", "object": "it" }));
//! assert!(logs[0]["msg"].as_str().unwrap().contains("to it"));
//!
//! // More application code
//! debug!(logger, "Another log"; "log_id" => "ABC123");
//! debug!(logger, "Imposter"; "log_id" => "XYZ123");
//!
//! // Alternate test code - parse selected logs and check their contents.
//! let abc_logs = slog_test::logs_in_range("ABC", "ABD", &mut data);
//! assert_eq!(abc_logs.len(), 1);
//! assert_eq!(abc_logs[0]["msg"].as_str().unwrap(), "Another log".to_string());
//! ```
//!
//! # Statistics testing
//!
//! For verifying statistics, the `create_logger_buffer` and `check_expected_stats` methods
//! are useful for creating a `slog_extlog::StatisticsLogger` and then verifying that statistics
//! are generated as expected.
#![allow(clippy::float_cmp)]
pub use super::stats::*;
use slog::o;
#[allow(unused_imports)] // we need this trait for lines()
use std::io::BufRead;
use std::sync::Mutex;
/// Buffer containing log data.
pub type Buffer = iobuffer::IoBuffer;
/// Create a new test logger suitable for use with `read_json_values`.
pub fn new_test_logger(data: Buffer) -> slog::Logger {
slog::Logger::root(
slog::Fuse::new(Mutex::new(slog_json::Json::default(data))),
o!(),
)
}
/// Read all the newline-delimited JSON objects from the given stream,
/// panicking if there is an IO error or a JSON parse error.
/// No attempt is made to avoid reading partial lines from the stream.
pub fn read_json_values(data: &mut Buffer) -> Vec<serde_json::Value> {
let iter = data.lines().map(move |line| {
serde_json::from_slice::<serde_json::Value>(&line).expect("JSON parse error")
});
iter.collect()
}
/// Test whether the given log lies in the given range: between
/// `min_id` (inclusive) and `max_id` (exclusive).
pub fn log_in_range(min_id: &str, max_id: &str, log: &serde_json::Value) -> bool {
match log["log_id"].as_str() {
Some(log_id) => log_id >= min_id && log_id < max_id,
None => false,
}
}
/// Collect all logs of the indicated type (see `log_in_range`) and sort them in
/// ascending order of log_id.
pub fn logs_in_range(min_id: &str, max_id: &str, data: &mut Buffer) -> Vec<serde_json::Value> {
let mut v = read_json_values(data)
.into_iter()
.filter(|log| log_in_range(min_id, max_id, log))
.collect::<Vec<_>>(); // LCOV_EXCL_LINE kcov bug?
v.sort_by_key(|log| log["log_id"].as_str().map(ToString::to_string));
v
}
/// Assert that every item contained in `expected` also appears in `actual`.
/// Additional values in `actual` are ignored.
pub fn assert_json_matches(actual: &serde_json::Value, expected: &serde_json::Value) {
fn check(
actual: &serde_json::Value,
expected: &serde_json::Value,
left: &serde_json::Value,
right: &serde_json::Value,
path: &str,
) {
if left.is_object() && right.is_object() {
for (key, value) in right.as_object().unwrap().iter() {
let path = format!("{}.{}", path, key);
check(actual, expected, &left[key], value, &path);
}
} else if left.is_array() && right.is_array() {
for (index, value) in right.as_array().unwrap().iter().enumerate() {
let path = format!("{}.{}", path, index);
check(actual, expected, &left[index], value, &path);
}
} else {
assert!(
left == right,
"Mismatch at {}:\nexpected:\n{}\nbut found:\n{}",
path,
expected,
actual
);
}
}
check(actual, expected, actual, expected, "");
}
/// A default logging interval for tests, short so UTs run faster.
pub static TEST_LOG_INTERVAL: u64 = 5;
#[cfg(feature = "interval_logging")]
fn new_stats_logger(stats: StatDefinitions, logger: slog::Logger) -> StatisticsLogger {
let builder = StatsLoggerBuilder::default();
builder
.with_stats(vec![stats])
.fuse_with_log_interval::<DefaultStatisticsLogFormatter>(TEST_LOG_INTERVAL, logger)
}
#[cfg(not(feature = "interval_logging"))]
fn new_stats_logger(stats: StatDefinitions, logger: slog::Logger) -> StatisticsLogger {
let builder = StatsLoggerBuilder::default();
builder.with_stats(vec![stats]).fuse(logger)
}
/// Common setup function.
///
/// Creates a logger using the provided statistics and buffer so we can easily
/// view the generated logs.
pub fn create_logger_buffer(stats: StatDefinitions) -> (StatisticsLogger, Buffer) {
let data = iobuffer::IoBuffer::new();
let logger = new_test_logger(data.clone());
let stats_logger = new_stats_logger(stats, logger);
(stats_logger, data)
}
/// An expected statistic helper method.
pub struct ExpectedStat {
/// Stat name E.g. "test_bucket_counter_grouped_freq"
pub stat_name: &'static str,
/// Stat tag E.g. Some("name=name,error=3,bucket=-5")
pub tag: Option<&'static str>,
/// Value of this stat E.g. 0f64
pub value: f64,
/// Type of metric for this stat E.g. "bucket_counter"
pub metric_type: &'static str,
}
/// Asserts that a set of logs (retrieved using `logs_in_range)` is exactly equal to an
/// expected set of stats.
///
/// Particularly useful for grouped stats.
pub fn check_expected_stats(logs: &[serde_json::Value], mut expected_stats: Vec<ExpectedStat>) {
for log in logs {
let mut matched = None;
for (id, exp) in expected_stats.iter().enumerate() {
if log["name"] == exp.stat_name
&& (exp.tag.is_none() || log["tags"] == exp.tag.unwrap())
{
assert_eq!(logs[0]["metric_type"], exp.metric_type);
assert_eq!(log["value"].as_f64(), Some(exp.value));
matched = Some(id);
break;
}
}
assert!(matched.is_some());
expected_stats.remove(matched.unwrap());
}
assert_eq!(expected_stats.len(), 0);
}
// LCOV_EXCL_START Don't test derives
/// ExpectedStatSnapshot helper.
/// E.g.
/// ExpectedStatSnapshot {
/// name: "test_group_bucket_counter",
/// description: "Test cumulative bucket counter with groups",
/// stat_type: BucketCounter,
/// values: vec![
/// ExpectedStatSnapshotValue {
/// group_values: vec!["one".to_string(), "two".to_string()],
/// bucket_limit: Some(BucketLimit::Num(-8)),
/// value: 0f64,
/// },
/// ExpectedStatSnapshotValue {
/// group_values: vec!["one".to_string(), "two".to_string()],
/// bucket_limit: Some(BucketLimit::Num(0)),
/// value: 0f64,
/// },
/// ExpectedStatSnapshotValue {
/// group_values: vec!["one".to_string(), "two".to_string()],
/// bucket_limit: Some(BucketLimit::Unbounded),
/// value: 3f64,
/// },
/// ExpectedStatSnapshotValue {
/// group_values: vec!["three".to_string(), "four".to_string()],
/// bucket_limit: Some(BucketLimit::Num(-8)),
/// value: 4f64,
/// },
/// ExpectedStatSnapshotValue {
/// group_values: vec!["three".to_string(), "four".to_string()],
/// bucket_limit: Some(BucketLimit::Num(0)),
/// value: 4f64,
/// },
/// ExpectedStatSnapshotValue {
/// group_values: vec!["three".to_string(), "four".to_string()],
/// bucket_limit: Some(BucketLimit::Unbounded),
/// value: 4f64,
/// },
/// ],
/// buckets: Some(Buckets::new(BucketMethod::CumulFreq, "bucket", &[-8, 0])),
/// }
#[derive(Debug)]
pub struct ExpectedStatSnapshot {
/// Name of the stat
pub name: &'static str,
/// Description of the stat
pub description: &'static str,
/// Type of the stat
pub stat_type: StatType,
/// A vec of the SnapShot values expected for this snapshot.
pub values: Vec<ExpectedStatSnapshotValue>,
/// The buckets for the stat.
pub buckets: Option<Buckets>,
}
/// ExpectedStatSnapshotValue helper.
#[derive(Debug)]
pub struct ExpectedStatSnapshotValue {
/// The group values (tags) for which this value for the Snapshot os grouped by,
pub group_values: Vec<String>,
/// The value of this snapshot.
pub value: f64,
/// The upper limit of the bucket which is represented by this snapshot.
pub bucket_limit: Option<BucketLimit>,
}
// LCOV_EXCL_STOP
/// Check that a set of stat snapshots are as expected.
pub fn check_expected_stat_snapshots(
stats: &[StatSnapshot],
expected_stats: &[ExpectedStatSnapshot],
) {
for stat in expected_stats {
let found_stat = stats.iter().find(|s| s.definition.name() == stat.name);
assert!(found_stat.is_some(), "Failed to find stat {}", stat.name);
let found_stat = found_stat.unwrap();
assert_eq!(found_stat.definition.stype(), stat.stat_type);
assert_eq!(found_stat.definition.description(), stat.description);
assert_eq!(found_stat.definition.buckets(), stat.buckets);
match found_stat.values {
StatSnapshotValues::Counter(ref vals) | StatSnapshotValues::Gauge(ref vals) => {
for value in &stat.values {
let found_value = vals
.iter()
.find(|val| val.group_values == value.group_values);
assert!(
found_value.is_some(),
"Failed to find value with groups {:?} and bucket_limit {:?} for stat {}",
value.group_values, // LCOV_EXCL_LINE
value.bucket_limit, // LCOV_EXCL_LINE
stat.name // LCOV_EXCL_LINE
);
let found_value = found_value.unwrap();
assert_eq!(found_value.group_values, value.group_values);
assert_eq!(found_value.value, value.value);
}
}
StatSnapshotValues::BucketCounter(ref buckets, ref vals) => {
assert_eq!(Some(buckets), stat.buckets.as_ref());
for value in &stat.values {
let found_value = vals.iter().find(|(val, bucket)| {
val.group_values == value.group_values
&& Some(bucket) == value.bucket_limit.as_ref()
});
assert!(
found_value.is_some(),
"Failed to find value with groups {:?} and bucket_limit {:?} for stat {}",
value.group_values, // LCOV_EXCL_LINE
value.bucket_limit, // LCOV_EXCL_LINE
stat.name // LCOV_EXCL_LINE
);
let (found_value, _) = found_value.unwrap();
assert_eq!(found_value.group_values, value.group_values);
assert_eq!(found_value.value, value.value);
}
}
}
}
assert_eq!(stats.len(), expected_stats.len());
}
#[cfg(test)]
mod tests {
use super::*;
use slog::debug;
use std::sync::mpsc;
use std::thread;
/// Ensure that partial writes don't cause JSON parsing errors.
#[test]
fn test_partial_write() {
// Set up the logger.
let mut data = iobuffer::IoBuffer::new();
let logger = new_test_logger(data.clone());
let (started_send, started_recv) = mpsc::channel();
let (done_send, done_recv) = mpsc::channel();
// In a separate thread, repeatedly write JSON values until
// told to stop. There are lots of fields, and serde `write()`s each
// value separately, so there's plenty of opportunity for reading an
// incomplete record.
let _ = thread::spawn(move || {
started_send.send(()).unwrap();
while done_recv.try_recv().is_err() {
debug!(logger, "Some data";
"alfa" => "alpha",
"bravo" => "beta",
"charlie" => "gamma",
"delta" => "delta",
"echo" => "epsilon");
}
});
// Wait until the thread has started.
started_recv.recv().unwrap();
// Now try to read some values. This should not fail with a parse
// error.
let _ = read_json_values(&mut data);
// Tell the daemon thread to stop so as not to leak CPU/memory.
done_send.send(()).unwrap();
}
}