[wrap] add test for message truncation

wrap/testdata/long.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	for i := 0; i < 100; i++ {
+		fmt.Println("Hello world!")
+	}
+	os.Exit(1)
+}

wrap/wrap_test.go

@@ -74,6 +74,30 @@ Note: This is note
 % go run testdata/stub.go
 Hello.
 exit status 1
+`,
+				NotificationInterval: 0,
+			},
+			ExitCode: 1,
+		},
+		{
+			Name: "long output",
+			Args: []string{
+				"-name=test-check",
+				"-detail",
+				"-note", "This is note",
+				"--",
+				"go", "run", "testdata/long.go",
+			},
+			Result: testResult{
+				Name:   "test-check",
+				Status: mackerel.CheckStatusCritical,
+				Message: `command exited with code: 1
+Note: This is note
+% go run testdata/long.go
+` + strings.Repeat("Hello world!\n", 33) + `Hello w
+...
+!
+` + strings.Repeat("Hello world!\n", 38) + `exit status 1
 `,
 				NotificationInterval: 0,
 			},