Added JSON output to libtest.

libtest: Json format now outputs failed tests' stdouts.

libtest: Json format now outputs failed tests' stdouts.

libtest: Json formatter now spews individiual events, not as an array

libtest: JSON fixes

libtest: Better JSON escaping

libtest: Test start event is printed on time

src/libtest/formatters.rs

@@ -12,12 +12,12 @@ use super::*;
 
 pub(crate) trait OutputFormatter {
     fn write_run_start(&mut self, len: usize) -> io::Result<()>;
-    fn write_test_start(&mut self,
-        test: &TestDesc,
-        align: NamePadding,
-        max_name_len: usize) -> io::Result<()>;
+    fn write_test_start(&mut self, test: &TestDesc) -> io::Result<()>;
     fn write_timeout(&mut self, desc: &TestDesc) -> io::Result<()>;
-    fn write_result(&mut self, result: &TestResult) -> io::Result<()>;
+    fn write_result(&mut self,
+                    desc: &TestDesc,
+                    result: &TestResult,
+                    stdout: &[u8]) -> io::Result<()>;
     fn write_run_finish(&mut self, state: &ConsoleTestState) -> io::Result<bool>;
 }
 
@@ -26,15 +26,17 @@ pub(crate) struct HumanFormatter<T> {
     terse: bool,
     use_color: bool,
     test_count: usize,
+    max_name_len: usize, // number of columns to fill when aligning names
 }
 
 impl<T: Write> HumanFormatter<T> {
-    pub fn new(out: OutputLocation<T>, use_color: bool, terse: bool) -> Self {
+    pub fn new(out: OutputLocation<T>, use_color: bool, terse: bool, max_name_len: usize) -> Self {
         HumanFormatter {
             out,
             terse,
             use_color,
             test_count: 0,
+            max_name_len,
         }
     }
 
@@ -73,7 +75,7 @@ impl<T: Write> HumanFormatter<T> {
                 // `stamp` in the rust CI).
                 self.write_plain("\n")?;
             }
-            
+
             self.test_count += 1;
             Ok(())
         } else {
@@ -170,20 +172,18 @@ impl<T: Write> OutputFormatter for HumanFormatter<T> {
         self.write_plain(&format!("\nrunning {} {}\n", len, noun))
     }
 
-    fn write_test_start(&mut self,
-                        test: &TestDesc,
-                        align: NamePadding,
-                        max_name_len: usize) -> io::Result<()> {
-        if self.terse && align != PadOnRight {
-            Ok(())
-        }
-        else {
-            let name = test.padded_name(max_name_len, align);
-            self.write_plain(&format!("test {} ... ", name))
-        }
+    fn write_test_start(&mut self, _desc: &TestDesc) -> io::Result<()> {
+        // Do not print header, as priting it at this point will result in
+        // an unreadable output when running tests concurrently.
+        Ok(())
     }
 
-    fn write_result(&mut self, result: &TestResult) -> io::Result<()> {
+    fn write_result(&mut self, desc: &TestDesc, result: &TestResult, _: &[u8]) -> io::Result<()> {
+        if !(self.terse && desc.name.padding() != PadOnRight) {
+            let name = desc.padded_name(self.max_name_len, desc.name.padding());
+            self.write_plain(&format!("test {} ... ", name))?;
+        }
+
         match *result {
             TrOk => self.write_ok(),
             TrFailed | TrFailedMsg(_) => self.write_failed(),
@@ -244,3 +244,203 @@ impl<T: Write> OutputFormatter for HumanFormatter<T> {
         Ok(success)
     }
 }
+
+pub(crate) struct JsonFormatter<T> {
+    out: OutputLocation<T>
+}
+
+impl<T: Write> JsonFormatter<T> {
+    pub fn new(out: OutputLocation<T>) -> Self {
+        Self {
+            out,        }
+    }
+
+    fn write_str<S: AsRef<str>>(&mut self, s: S) -> io::Result<()> {
+        self.out.write_all(s.as_ref().as_ref())?;
+        self.out.write_all("\n".as_ref())
+    }
+
+    fn write_event(&mut self,
+                    ty: &str,
+                    name: &str,
+                    evt: &str,
+                    extra: Option<String>) -> io::Result<()> {
+        if let Some(extras) = extra {
+            self.write_str(&*format!(r#"{{ "type": "{}", "name": "{}", "event": "{}", {} }}"#,
+                                    ty,
+                                    name,
+                                    evt,
+                                    extras))
+        }
+        else {
+            self.write_str(&*format!(r#"{{ "type": "{}", "name": "{}", "event": "{}" }}"#,
+                                    ty,
+                                    name,
+                                    evt))
+        }
+    }
+}
+
+impl<T: Write> OutputFormatter for JsonFormatter<T> {
+    fn write_run_start(&mut self, len: usize) -> io::Result<()> {
+        self.write_str(
+            &*format!(r#"{{ "type": "suite", "event": "started", "test_count": "{}" }}"#, len))
+    }
+
+    fn write_test_start(&mut self, desc: &TestDesc) -> io::Result<()> {
+        self.write_str(&*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 {
+                    "".into()
+                }
+                else {
+                    format!(r#", "mib_per_second": {}"#, bs.mb_s)
+                };
+
+                let line = format!("{{ \"type\": \"bench\", \
+                                \"name\": \"{}\", \
+                                \"median\": {}, \
+                                \"deviation\": {}{} }}",
+                        desc.name,
+                        median,
+                        deviation,
+                        mbps);
+
+                self.write_str(&*line)
+            },
+        }
+    }
+
+    fn write_timeout(&mut self, desc: &TestDesc) -> io::Result<()> {
+        self.write_str(&*format!(r#"{{ "type": "test", "event": "timeout", "name": "{}" }}"#,
+                        desc.name))
+    }
+
+    fn write_run_finish(&mut self, state: &ConsoleTestState) -> io::Result<bool> {
+
+        self.write_str(&*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(())
+    }
+}