1 files changed, 141 insertions, 0 deletions
diff --git a/tests/src/logger.rs b/tests/src/logger.rs
new file mode 100644
index 00000000..c48650a7
--- /dev/null
+++ b/tests/src/logger.rs
@@ -0,0 +1,141 @@
+use std::io::{self, IsTerminal, StderrLock, Write};
+use std::time::{Duration, Instant};
+
+use crate::collect::Test;
+use crate::run::TestResult;
+
+/// Receives status updates by individual test runs.
+pub struct Logger<'a> {
+    filtered: usize,
+    passed: usize,
+    failed: usize,
+    skipped: usize,
+    mismatched_image: bool,
+    active: Vec<&'a Test>,
+    last_change: Instant,
+    temp_lines: usize,
+    terminal: bool,
+}
+
+impl<'a> Logger<'a> {
+    /// Create a new logger.
+    pub fn new(filtered: usize, skipped: usize) -> Self {
+        Self {
+            filtered,
+            passed: 0,
+            failed: 0,
+            skipped,
+            mismatched_image: false,
+            active: vec![],
+            temp_lines: 0,
+            last_change: Instant::now(),
+            terminal: std::io::stderr().is_terminal(),
+        }
+    }
+
+    /// Register the start of a test.
+    pub fn start(&mut self, test: &'a Test) {
+        self.active.push(test);
+        self.last_change = Instant::now();
+        self.refresh();
+    }
+
+    /// Register a finished test.
+    pub fn end(&mut self, test: &'a Test, result: std::thread::Result<TestResult>) {
+        self.active.retain(|t| t.name != test.name);
+
+        let result = match result {
+            Ok(result) => result,
+            Err(_) => {
+                self.failed += 1;
+                self.temp_lines = 0;
+                self.print(move |out| {
+                    writeln!(out, "❌ {test} panicked")?;
+                    Ok(())
+                })
+                .unwrap();
+                return;
+            }
+        };
+
+        if result.is_ok() {
+            self.passed += 1;
+        } else {
+            self.failed += 1;
+        }
+
+        self.mismatched_image |= result.mismatched_image;
+        self.last_change = Instant::now();
+
+        self.print(move |out| {
+            if !result.errors.is_empty() {
+                writeln!(out, "❌ {test}")?;
+                for line in result.errors.lines() {
+                    writeln!(out, "  {line}")?;
+                }
+            } else if crate::ARGS.verbose || !result.infos.is_empty() {
+                writeln!(out, "✅ {test}")?;
+            }
+            for line in result.infos.lines() {
+                writeln!(out, "  {line}")?;
+            }
+            Ok(())
+        })
+        .unwrap();
+    }
+
+    /// Prints a summary and returns whether the test suite passed.
+    pub fn finish(&self) -> bool {
+        let Self { filtered, passed, failed, skipped, .. } = *self;
+
+        eprintln!("{passed} passed, {failed} failed, {skipped} skipped");
+        assert_eq!(filtered, passed + failed, "not all tests were executed succesfully");
+
+        if self.mismatched_image {
+            eprintln!("  pass the --update flag to update the reference images");
+        }
+
+        self.failed == 0
+    }
+
+    /// Refresh the status.
+    pub fn refresh(&mut self) {
+        self.print(|_| Ok(())).unwrap();
+    }
+
+    /// Refresh the status print.
+    fn print(
+        &mut self,
+        inner: impl FnOnce(&mut StderrLock<'_>) -> io::Result<()>,
+    ) -> io::Result<()> {
+        let mut out = std::io::stderr().lock();
+
+        // Clear the status lines.
+        for _ in 0..self.temp_lines {
+            write!(out, "\x1B[1F\x1B[0J")?;
+            self.temp_lines = 0;
+        }
+
+        // Print the result of a finished test.
+        inner(&mut out)?;
+
+        // Print the status line.
+        let done = self.failed + self.passed;
+        if done < self.filtered {
+            if self.last_change.elapsed() > Duration::from_secs(2) {
+                for test in &self.active {
+                    writeln!(out, "⏰ {test} is taking a long time ...")?;
+                    if self.terminal {
+                        self.temp_lines += 1;
+                    }
+                }
+            }
+            if self.terminal {
+                writeln!(out, "💨 {done} / {}", self.filtered)?;
+                self.temp_lines += 1;
+            }
+        }
+
+        Ok(())
+    }
+}