1 files changed, 208 insertions, 0 deletions
diff --git a/src/libtest/formatters/json.rs b/src/libtest/formatters/json.rs
new file mode 100644
index 00000000000..a06497f9862
--- /dev/null
+++ b/src/libtest/formatters/json.rs
@@ -0,0 +1,208 @@
+use super::*;
+
+pub(crate) struct JsonFormatter<T> {
+    out: OutputLocation<T>,
+}
+
+impl<T: Write> JsonFormatter<T> {
+    pub fn new(out: OutputLocation<T>) -> Self {
+        Self { out }
+    }
+
+    fn write_message(&mut self, s: &str) -> io::Result<()> {
+        assert!(!s.contains('\n'));
+
+        self.out.write_all(s.as_ref())?;
+        self.out.write_all(b"\n")
+    }
+
+    fn write_event(
+        &mut self,
+        ty: &str,
+        name: &str,
+        evt: &str,
+        extra: Option<String>,
+    ) -> io::Result<()> {
+        if let Some(extras) = extra {
+            self.write_message(&*format!(
+                r#"{{ "type": "{}", "name": "{}", "event": "{}", {} }}"#,
+                ty, name, evt, extras
+            ))
+        } else {
+            self.write_message(&*format!(
+                r#"{{ "type": "{}", "name": "{}", "event": "{}" }}"#,
+                ty, name, evt
+            ))
+        }
+    }
+}
+
+impl<T: Write> OutputFormatter for JsonFormatter<T> {
+    fn write_run_start(&mut self, test_count: usize) -> io::Result<()> {
+        self.write_message(&*format!(
+            r#"{{ "type": "suite", "event": "started", "test_count": {} }}"#,
+            test_count
+        ))
+    }
+
+    fn write_test_start(&mut self, desc: &TestDesc) -> io::Result<()> {
+        self.write_message(&*format!(
+            r#"{{ "type": "test", "event": "started", "name": "{}" }}"#,
+            desc.name
+        ))
+    }
+
+    fn write_result(
+        &mut self,
+        desc: &TestDesc,
+        result: &TestResult,
+        stdout: &[u8],
+    ) -> io::Result<()> {
+        match *result {
+            TrOk => self.write_event("test", desc.name.as_slice(), "ok", None),
+
+            TrFailed => {
+                let extra_data = if stdout.len() > 0 {
+                    Some(format!(
+                        r#""stdout": "{}""#,
+                        EscapedString(String::from_utf8_lossy(stdout))
+                    ))
+                } else {
+                    None
+                };
+
+                self.write_event("test", desc.name.as_slice(), "failed", extra_data)
+            }
+
+            TrFailedMsg(ref m) => self.write_event(
+                "test",
+                desc.name.as_slice(),
+                "failed",
+                Some(format!(r#""message": "{}""#, EscapedString(m))),
+            ),
+
+            TrIgnored => self.write_event("test", desc.name.as_slice(), "ignored", None),
+
+            TrAllowedFail => {
+                self.write_event("test", desc.name.as_slice(), "allowed_failure", None)
+            }
+
+            TrBench(ref bs) => {
+                let median = bs.ns_iter_summ.median as usize;
+                let deviation = (bs.ns_iter_summ.max - bs.ns_iter_summ.min) as usize;
+
+                let mbps = if bs.mb_s == 0 {
+                    String::new()
+                } else {
+                    format!(r#", "mib_per_second": {}"#, bs.mb_s)
+                };
+
+                let line = format!(
+                    "{{ \"type\": \"bench\", \
+                     \"name\": \"{}\", \
+                     \"median\": {}, \
+                     \"deviation\": {}{} }}",
+                    desc.name, median, deviation, mbps
+                );
+
+                self.write_message(&*line)
+            }
+        }
+    }
+
+    fn write_timeout(&mut self, desc: &TestDesc) -> io::Result<()> {
+        self.write_message(&*format!(
+            r#"{{ "type": "test", "event": "timeout", "name": "{}" }}"#,
+            desc.name
+        ))
+    }
+
+    fn write_run_finish(&mut self, state: &ConsoleTestState) -> io::Result<bool> {
+        self.write_message(&*format!(
+            "{{ \"type\": \"suite\", \
+             \"event\": \"{}\", \
+             \"passed\": {}, \
+             \"failed\": {}, \
+             \"allowed_fail\": {}, \
+             \"ignored\": {}, \
+             \"measured\": {}, \
+             \"filtered_out\": {} }}",
+            if state.failed == 0 { "ok" } else { "failed" },
+            state.passed,
+            state.failed + state.allowed_fail,
+            state.allowed_fail,
+            state.ignored,
+            state.measured,
+            state.filtered_out
+        ))?;
+
+        Ok(state.failed == 0)
+    }
+}
+
+/// A formatting utility used to print strings with characters in need of escaping.
+/// Base code taken form `libserialize::json::escape_str`
+struct EscapedString<S: AsRef<str>>(S);
+
+impl<S: AsRef<str>> ::std::fmt::Display for EscapedString<S> {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
+        let mut start = 0;
+
+        for (i, byte) in self.0.as_ref().bytes().enumerate() {
+            let escaped = match byte {
+                b'"' => "\\\"",
+                b'\\' => "\\\\",
+                b'\x00' => "\\u0000",
+                b'\x01' => "\\u0001",
+                b'\x02' => "\\u0002",
+                b'\x03' => "\\u0003",
+                b'\x04' => "\\u0004",
+                b'\x05' => "\\u0005",
+                b'\x06' => "\\u0006",
+                b'\x07' => "\\u0007",
+                b'\x08' => "\\b",
+                b'\t' => "\\t",
+                b'\n' => "\\n",
+                b'\x0b' => "\\u000b",
+                b'\x0c' => "\\f",
+                b'\r' => "\\r",
+                b'\x0e' => "\\u000e",
+                b'\x0f' => "\\u000f",
+                b'\x10' => "\\u0010",
+                b'\x11' => "\\u0011",
+                b'\x12' => "\\u0012",
+                b'\x13' => "\\u0013",
+                b'\x14' => "\\u0014",
+                b'\x15' => "\\u0015",
+                b'\x16' => "\\u0016",
+                b'\x17' => "\\u0017",
+                b'\x18' => "\\u0018",
+                b'\x19' => "\\u0019",
+                b'\x1a' => "\\u001a",
+                b'\x1b' => "\\u001b",
+                b'\x1c' => "\\u001c",
+                b'\x1d' => "\\u001d",
+                b'\x1e' => "\\u001e",
+                b'\x1f' => "\\u001f",
+                b'\x7f' => "\\u007f",
+                _ => {
+                    continue;
+                }
+            };
+
+            if start < i {
+                f.write_str(&self.0.as_ref()[start..i])?;
+            }
+
+            f.write_str(escaped)?;
+
+            start = i + 1;
+        }
+
+        if start != self.0.as_ref().len() {
+            f.write_str(&self.0.as_ref()[start..])?;
+        }
+
+        Ok(())
+    }
+}