avoid run time in summary for yarn 1

internal/logger/logger.go

@@ -608,7 +608,7 @@ func (t SummaryTable) Less(i int, j int) bool {
 // Show a warning icon next to output files that are 1mb or larger
 const sizeWarningThreshold = 1024 * 1024
 
-func PrintSummary(useColor UseColor, table SummaryTable, start time.Time) {
+func PrintSummary(useColor UseColor, table SummaryTable, start *time.Time) {
 	PrintTextWithColor(os.Stderr, useColor, func(colors Colors) string {
 		isProbablyWindowsCommandPrompt := false
 		sb := strings.Builder{}
@@ -675,7 +675,7 @@ func PrintSummary(useColor UseColor, table SummaryTable, start time.Time) {
 			if layoutWidth > maxPath+maxSize {
 				layoutWidth = maxPath + maxSize
 			}
-			sb.WriteString("\n")
+			sb.WriteByte('\n')
 
 			for _, entry := range table {
 				dir, base := entry.Dir, entry.Base
@@ -751,12 +751,17 @@ func PrintSummary(useColor UseColor, table SummaryTable, start time.Time) {
 			lightningSymbol = ""
 		}
 
-		sb.WriteString(fmt.Sprintf("\n%s%sDone in %dms%s\n\n",
+		// Printing the time taken is optional
+		if start != nil {
+			sb.WriteString(fmt.Sprintf("\n%s%sDone in %dms%s\n",
 				lightningSymbol,
 				colors.Green,
-			time.Since(start).Milliseconds(),
+				time.Since(*start).Milliseconds(),
 				colors.Default,
 			))
+		}
+
+		sb.WriteByte('\n')
 		return sb.String()
 	})
 }

pkg/api/api_impl.go

@@ -654,7 +654,16 @@ func printSummary(logOptions logger.OutputOptions, outputFiles []OutputFile, sta
 		}
 	}
 
-	logger.PrintSummary(logOptions.Color, table, start)
+	// Don't print the time taken by the build if we're running under Yarn 1
+	// since Yarn 1 always prints its own copy of the time taken by each command
+	for _, env := range os.Environ() {
+		if strings.HasPrefix(env, "npm_config_user_agent=") && strings.Contains(env, "yarn/1.") {
+			logger.PrintSummary(logOptions.Color, table, nil)
+			return
+		}
+	}
+
+	logger.PrintSummary(logOptions.Color, table, &start)
 }
 
 func rebuildImpl(