support libtest json output

CHANGELOG.md

@@ -38,3 +38,9 @@
 - Updated `derive_builder` to the latest version.
 - Made use of `matches!` macros where possible.
 - Fixed some tests
+
+## [0.15.1] - 2022-10-13
+
+### Added
+
+- Added `TestMessage`, `TestEvent`, `SuiteEvent` for parsing the `cargo test -- --format json` output.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cargo_metadata"
-version = "0.18.0"
+version = "0.18.1"
 authors = ["Oliver Schneider <[email protected]>"]
 repository = "https://github.com/oli-obk/cargo_metadata"
 description = "structured access to the output of `cargo metadata`"
@@ -21,6 +21,7 @@ thiserror = "1.0.31"
 [features]
 default = []
 builder = ["derive_builder"]
+unstable = []
 
 [package.metadata.cargo_metadata_test]
 some_field = true

src/lib.rs

@@ -99,6 +99,8 @@ pub use dependency::DependencyBuilder;
 pub use dependency::{Dependency, DependencyKind};
 use diagnostic::Diagnostic;
 pub use errors::{Error, Result};
+#[cfg(feature = "unstable")]
+pub use libtest::TestMessage;
 #[allow(deprecated)]
 pub use messages::parse_messages;
 pub use messages::{
@@ -115,6 +117,8 @@ use serde::{Deserialize, Deserializer, Serialize};
 mod dependency;
 pub mod diagnostic;
 mod errors;
+#[cfg(feature = "unstable")]
+pub mod libtest;
 mod messages;
 
 /// An "opaque" identifier for a package.

src/libtest.rs

@@ -0,0 +1,165 @@
+//! Parses output of [libtest](https://github.com/rust-lang/rust/blob/master/library/test/src/formatters/json.rs).
+//!
+//! Since this module parses output in an unstable format, all structs in this module may change at any time, and are exempt from semver guarantees.
+use serde::{Deserialize, Serialize};
+
+/// Suite related event
+#[derive(Debug, PartialEq, Deserialize, Serialize)]
+#[serde(tag = "event")]
+#[serde(rename_all = "lowercase")]
+/// Suite event
+pub enum SuiteEvent {
+    /// emitted on the start of a test run, and the start of the doctests
+    Started {
+        /// number of tests in this suite
+        test_count: usize,
+    },
+    /// the suite has finished
+    Ok {
+        /// the number of tests that passed
+        passed: usize,
+        /// the number of tests that failed
+        failed: usize,
+        /// number of tests that were ignored
+        ignored: usize,
+        /// number of benchmarks run
+        measured: usize,
+        /// i think this is based on what you specify in the cargo test argument
+        filtered_out: usize,
+        /// how long the suite took to run
+        exec_time: f32,
+    },
+    /// the suite has at least one failing test
+    Failed {
+        /// the number of tests that passed
+        passed: usize,
+        /// the number of tests that failed
+        failed: usize,
+        /// number of tests that were ignored
+        ignored: usize,
+        /// i think its something to do with benchmarks?
+        measured: usize,
+        /// i think this is based on what you specify in the cargo test argument
+        filtered_out: usize,
+        /// how long the suite took to run
+        exec_time: f32,
+    },
+}
+
+#[derive(Debug, PartialEq, Deserialize, Serialize)]
+#[serde(tag = "event")]
+#[serde(rename_all = "lowercase")]
+/// Test event
+pub enum TestEvent {
+    /// a new test starts
+    Started {
+        /// the name of this test
+        name: String,
+    },
+    /// the test has finished
+    Ok {
+        /// which one
+        name: String,
+        /// in how long
+        exec_time: f32,
+        /// what did it say?
+        stdout: Option<String>,
+    },
+    /// the test has failed
+    Failed {
+        /// which one
+        name: String,
+        /// in how long
+        exec_time: f32,
+        /// why?
+        stdout: Option<String>,
+        /// it timed out?
+        reason: Option<String>,
+        /// what message
+        message: Option<String>,
+    },
+    /// the test has been ignored
+    Ignored {
+        /// which one
+        name: String,
+    },
+    /// the test has timed out
+    Timeout {
+        /// which one
+        name: String,
+    },
+}
+
+impl TestEvent {
+    /// Get the name of this test
+    pub fn name(&self) -> &str {
+        let (Self::Started { name }
+        | Self::Ok { name, .. }
+        | Self::Ignored { name }
+        | Self::Failed { name, .. }
+        | Self::Timeout { name }) = self;
+        name
+    }
+
+    /// Get the stdout of this test, if available.
+    pub fn stdout(&self) -> Option<&str> {
+        match self {
+            Self::Ok { stdout, .. } | Self::Failed { stdout, .. } => stdout.as_deref(),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Deserialize, Serialize)]
+/// Represents the output of `cargo test -- -Zunstable-options --report-time --show-output --format json`.
+///
+/// requires --report-time
+///
+/// # Stability
+///
+/// As this struct is for interfacing with the unstable libtest json output, this struct may change at any time, without semver guarantees.
+#[serde(tag = "type")]
+#[serde(rename_all = "lowercase")]
+pub enum TestMessage {
+    /// suite related message
+    Suite(SuiteEvent),
+    /// test related message
+    Test(TestEvent),
+    /// bench related message
+    Bench {
+        /// name of benchmark
+        name: String,
+        /// distribution
+        median: f32,
+        /// deviation
+        deviation: f32,
+        /// thruput in MiB per second
+        mib_per_second: Option<f32>,
+    },
+}
+
+#[test]
+fn deser() {
+    macro_rules! run {
+        ($($input:literal parses to $output:expr),+) => {
+            $(assert_eq!(dbg!(serde_json::from_str::<TestMessage>($input)).unwrap(), $output);)+
+        };
+    }
+    run![
+        r#"{ "type": "suite", "event": "started", "test_count": 2 }"# parses to TestMessage::Suite(SuiteEvent::Started { test_count: 2 }),
+        r#"{ "type": "test", "event": "started", "name": "fail" }"# parses to TestMessage::Test(TestEvent::Started { name: "fail".into() }),
+        r#"{ "type": "test", "name": "fail", "event": "ok", "exec_time": 0.000003428, "stdout": "hello world" }"# parses to TestMessage::Test(TestEvent::Ok { name: "fail".into(), exec_time: 0.000003428, stdout: Some("hello world".into()) }),
+        r#"{ "type": "test", "event": "started", "name": "nope" }"# parses to TestMessage::Test(TestEvent::Started { name: "nope".into() }),
+        r#"{ "type": "test", "name": "nope", "event": "ignored" }"# parses to TestMessage::Test(TestEvent::Ignored { name: "nope".into() }),
+        r#"{ "type": "suite", "event": "ok", "passed": 1, "failed": 0, "ignored": 1, "measured": 0, "filtered_out": 0, "exec_time": 0.000684028 }"# parses to TestMessage::Suite(SuiteEvent::Ok { passed: 1, failed: 0, ignored: 1, measured: 0, filtered_out: 0, exec_time: 0.000684028 })
+    ];
+
+    run![
+        r#"{ "type": "suite", "event": "started", "test_count": 2 }"# parses to TestMessage::Suite(SuiteEvent::Started { test_count: 2 }),
+        r#"{ "type": "test", "event": "started", "name": "fail" }"# parses to TestMessage::Test(TestEvent::Started { name: "fail".into() }),
+        r#"{ "type": "test", "event": "started", "name": "benc" }"# parses to TestMessage::Test(TestEvent::Started { name: "benc".into() }),
+        r#"{ "type": "bench", "name": "benc", "median": 0, "deviation": 0 }"# parses to TestMessage::Bench { name: "benc".into(), median: 0., deviation: 0., mib_per_second: None },
+        r#"{ "type": "test", "name": "fail", "event": "failed", "exec_time": 0.000081092, "stdout": "thread 'fail' panicked" }"# parses to TestMessage::Test(TestEvent::Failed { name: "fail".into(), exec_time: 0.000081092, stdout: Some("thread 'fail' panicked".into()), reason: None, message: None} ),
+        r#"{ "type": "suite", "event": "failed", "passed": 0, "failed": 1, "ignored": 0, "measured": 1, "filtered_out": 0, "exec_time": 0.000731068 }"# parses to TestMessage::Suite(SuiteEvent::Failed { passed: 0, failed: 1, ignored: 0, measured: 1, filtered_out: 0, exec_time: 0.000731068 })
+    ];
+}