Merge pull request #1940 from vvoland/history-fix-long-lines

history: Fix loading very long lines

Author: dgageot

pkg/history/history.go

@@ -1,8 +1,8 @@
 package history
 
 import (
-	"bufio"
 	"encoding/json"
+	"io"
 	"os"
 	"path/filepath"
 	"slices"
@@ -215,24 +215,18 @@ func (h *History) load() error {
 	defer f.Close()
 
 	var all []string
-	scanner := bufio.NewScanner(f)
-	for scanner.Scan() {
-		line := scanner.Text()
-		if line == "" {
-			continue
-		}
-
+	dec := json.NewDecoder(f)
+	for {
 		var message string
-		if err := json.Unmarshal([]byte(line), &message); err != nil {
+		if err := dec.Decode(&message); err != nil {
+			if err == io.EOF {
+				break
+			}
 			continue
 		}
 		all = append(all, message)
 	}
 
-	if err := scanner.Err(); err != nil {
-		return err
-	}
-
 	// Deduplicate keeping the latest occurrence of each message
 	seen := make(map[string]bool)
 	for i := len(all) - 1; i >= 0; i-- {

pkg/history/history_test.go

@@ -417,3 +417,28 @@ func TestHistory_SetCurrent(t *testing.T) {
 	h.SetCurrent(2)
 	assert.Empty(t, h.Next())
 }
+
+func TestHistory_VeryLongMessage(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	h, err := New(WithBaseDir(tmpDir))
+	require.NoError(t, err)
+
+	// Create a message longer than bufio.Scanner's default 64KB limit
+	longMessage := make([]byte, 100*1024) // 100KB
+	for i := range longMessage {
+		longMessage[i] = 'a' + byte(i%26)
+	}
+	longStr := string(longMessage)
+
+	require.NoError(t, h.Add(longStr))
+	require.NoError(t, h.Add("short message after"))
+
+	// Reload history from disk
+	h2, err := New(WithBaseDir(tmpDir))
+	require.NoError(t, err)
+
+	require.Len(t, h2.Messages, 2)
+	assert.Equal(t, longStr, h2.Messages[0])
+	assert.Equal(t, "short message after", h2.Messages[1])
+}