Catch errors in goroutines and log them

m/pager.go

@@ -322,6 +322,10 @@ func (p *Pager) StartPaging(screen twin.Screen, chromaStyle *chroma.Style, chrom
 	p.marks = make(map[rune]scrollPosition)
 
 	go func() {
+		defer func() {
+			panicHandler("StartPaging()/moreLinesAvailable", recover())
+		}()
+
 		for range p.reader.moreLinesAdded {
 			// Notify the main loop about the new lines so it can show them
 			screen.Events() <- eventMoreLinesAvailable{}
@@ -337,6 +341,10 @@ func (p *Pager) StartPaging(screen twin.Screen, chromaStyle *chroma.Style, chrom
 	}()
 
 	go func() {
+		defer func() {
+			panicHandler("StartPaging()/spinner", recover())
+		}()
+
 		// Spin the spinner as long as contents is still loading
 		spinnerFrames := [...]string{"/.\\", "-o-", "\\O/", "| |"}
 		spinnerIndex := 0
@@ -359,6 +367,10 @@ func (p *Pager) StartPaging(screen twin.Screen, chromaStyle *chroma.Style, chrom
 	}()
 
 	go func() {
+		defer func() {
+			panicHandler("StartPaging()/maybeDone", recover())
+		}()
+
 		for range p.reader.maybeDone {
 			screen.Events() <- eventMaybeDone{}
 		}

m/panicHandler.go

@@ -0,0 +1,17 @@
+package m
+
+// NOTE: This file should be identical to twin/panicHandler.go
+
+import (
+	log "github.com/sirupsen/logrus"
+)
+
+func panicHandler(goroutineName string, recoverResult any) {
+	if recoverResult == nil {
+		return
+	}
+
+	log.WithFields(log.Fields{
+		"recoverResult": recoverResult,
+	}).Error("Goroutine panicked: " + goroutineName)
+}

m/reader.go

@@ -342,7 +342,7 @@ func NewReaderFromStream(name string, reader io.Reader, style chroma.Style, form
 // then used for pre-allocating the lines slice, which improves large file
 // loading performance.
 //
-// If lexer is not nil, the file will be highlighted after being fully read.
+// If lexer is set, the file will be highlighted after being fully read.
 //
 // Note that you must call reader.SetStyleForHighlighting() after this to get
 // highlighting.
@@ -364,9 +364,13 @@ func newReaderFromStream(reader io.Reader, originalFileName *string, formatter c
 		done:                    &done,
 	}
 
-	// FIXME: Make sure that if we panic somewhere inside of this goroutine,
-	// the main program terminates and prints our panic stack trace.
-	go returnMe.readStream(reader, formatter, lexer)
+	go func() {
+		defer func() {
+			panicHandler("newReaderFromStream()/readStream()", recover())
+		}()
+
+		returnMe.readStream(reader, formatter, lexer)
+	}()
 
 	return &returnMe
 }

m/search.go

@@ -124,6 +124,10 @@ func (p *Pager) findFirstHit(startPosition linenumbers.LineNumber, beforePositio
 		}
 
 		go func(i int, searchStart linenumbers.LineNumber, chunkBefore *linenumbers.LineNumber) {
+			defer func() {
+				panicHandler("findFirstHit()/chunkSearch", recover())
+			}()
+
 			findings[i] <- p._findFirstHit(searchStart, chunkBefore, backwards)
 		}(i, searchStart, chunkBefore)
 	}

twin/panicHandler.go

@@ -0,0 +1,17 @@
+package twin
+
+// NOTE: This file should be identical to m/panicHandler.go
+
+import (
+	log "github.com/sirupsen/logrus"
+)
+
+func panicHandler(goroutineName string, recoverResult any) {
+	if recoverResult == nil {
+		return
+	}
+
+	log.WithFields(log.Fields{
+		"recoverResult": recoverResult,
+	}).Error("Goroutine panicked: " + goroutineName)
+}

twin/screen-setup.go

@@ -117,6 +117,10 @@ func (screen *UnixScreen) setupSigwinchNotification() {
 	sigwinch := make(chan os.Signal, 1)
 	signal.Notify(sigwinch, syscall.SIGWINCH)
 	go func() {
+		defer func() {
+			panicHandler("setupSigwinchNotification()/SIGWINCH", recover())
+		}()
+
 		for {
 			// Await window resize signal
 			<-sigwinch

twin/screen-setup_test.go

@@ -31,6 +31,10 @@ func TestInterruptableReader_blockedOnReadImmediate(t *testing.T) {
 	}
 	readResultChan := make(chan readResult)
 	go func() {
+		defer func() {
+			panicHandler("TestInterruptableReader_blockedOnReadImmediate()", recover())
+		}()
+
 		buffer := make([]byte, 1)
 		n, err := testMe.Read(buffer)
 		readResultChan <- readResult{n, err}

twin/screen.go

@@ -179,7 +179,13 @@ func NewScreenWithMouseModeAndColorType(mouseMode MouseMode, terminalColorCount
 
 	screen.hideCursor(true)
 
-	go screen.mainLoop()
+	go func() {
+		defer func() {
+			panicHandler("NewScreenWithMouseModeAndColorType()/mainLoop()", recover())
+		}()
+
+		screen.mainLoop()
+	}()
 
 	return &screen, nil
 }

twin/screen_test.go

@@ -269,6 +269,10 @@ func TestInterruptableReader_blockedOnRead(t *testing.T) {
 	}
 	readResultChan := make(chan readResult)
 	go func() {
+		defer func() {
+			panicHandler("TestInterruptableReader_blockedOnRead()", recover())
+		}()
+
 		buffer := make([]byte, 1)
 		n, err := testMe.Read(buffer)
 		readResultChan <- readResult{n, err}