Return lines with error and print the previous 10 and next 10 lines

Author: samueld-activator

cmd/state-mcp/internal/registry/tools.go

@@ -96,7 +96,8 @@ func DownloadLogsTool() Tool {
 			}
 
 			runner := downloadlogs.New(p)
-			params := downloadlogs.NewParams(url)
+			params := downloadlogs.NewParams()
+			params.LogUrl = url
 			err = runner.Run(params)
 			if err != nil {
 				return mcp.NewToolResultError(fmt.Sprintf("error downloading logs: %s", errs.JoinMessage(err))), nil

internal/runners/mcp/downloadlogs/downloadlogs.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"strings"
 
 	"github.com/ActiveState/cli/internal/output"
 	"github.com/ActiveState/cli/internal/primer"
@@ -22,13 +23,11 @@ func New(p *primer.Values) *DownloadLogsRunner {
 }
 
 type Params struct {
-	logUrl string
+	LogUrl string
 }
 
-func NewParams(logUrl string) *Params {
-	return &Params{
-		logUrl: logUrl,
-	}
+func NewParams() *Params {
+	return &Params{}
 }
 
 // Example: {"body": {"facility": "INFO", "msg": "..."}, "artifact_id": "...", "timestamp": "2025-08-12T19:23:51.702971", "type": "artifact_progress", "source": "build-wrapper", "pid": 19}
@@ -39,44 +38,58 @@ type LogLine struct {
 }
 
 func (runner *DownloadLogsRunner) Run(params *Params) error {
-	response, err := http.Get(params.logUrl)
+	response, err := http.Get(params.LogUrl)
 	if err != nil {
 		return fmt.Errorf("error while downloading logs: %v", err)
 	}
 	defer response.Body.Close()
 
-	if response.StatusCode != 200 {
+	if response.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(response.Body)
 		return fmt.Errorf("error fetching logs: status %d, %s", response.StatusCode, body)
 	}
 
 	scanner := bufio.NewScanner(response.Body)
 
-	startPrinting := false
-
+	// Read all lines, parse and only store the text messages
+	var lines []string
 	for scanner.Scan() {
-		var logLine LogLine
 		line := scanner.Text()
-
+		var logLine LogLine
 		if err := json.Unmarshal([]byte(line), &logLine); err != nil {
-			continue // Skip malformed lines
-		}
-
-		msg := logLine.Body.Msg
-
-		if !startPrinting {
-			if msg == "Dependencies downloaded and unpacked." {
-				startPrinting = true
-			}
 			continue
 		}
-
-		runner.output.Print(msg + "\n")
+		lines = append(lines, logLine.Body.Msg)
 	}
-
 	if err := scanner.Err(); err != nil {
 		return fmt.Errorf("error reading log content: %v", err)
 	}
 
+	// Check what lines contain the keyword "error" and print the previous 10 and next 10 lines
+	printedLines := make(map[int]bool)
+	for i, line := range lines {
+		if strings.Contains(strings.ToLower(line), "error") {
+			start := i - 10
+			if start < 0 {
+				start = 0
+			}
+			end := i + 10
+			if end >= len(lines) {
+				end = len(lines) - 1
+			}
+
+			for j := start; j <= end; j++ {
+				if !printedLines[j] {
+					// Print ellipsis if there are skipped lines
+					if j > 0 && !printedLines[j-1] {
+						runner.output.Print("[...]")
+					}
+					runner.output.Print(lines[j])
+					printedLines[j] = true
+				}
+			}
+		}
+	}
+
 	return nil
 }