fix(test): Wait for Vault server in watch tests

Fix flaky tests by polling Vault's /v1/sys/health endpoint.
This ensures the server is ready before tests attempt to connect,
preventing a race condition during Vault dev server startup.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

Author: thevilledev

watch/watch_test.go

@@ -7,11 +7,13 @@ import (
 	"encoding/json"
 	"io"
 	"log"
+	"net/http"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	dep "github.com/hashicorp/consul-template/dependency"
 	"github.com/hashicorp/vault/api"
@@ -79,6 +81,30 @@ func newTestVault() *vaultServer {
 	if err := cmd.Start(); err != nil {
 		panic("vault failed to start: " + err.Error())
 	}
+
+	// Wait for Vault to become available
+	client := &http.Client{Timeout: 1 * time.Second}
+	healthURL := vaultAddr + "/v1/sys/health"
+	startTime := time.Now()
+	timeout := 30 * time.Second
+
+	for {
+		if time.Since(startTime) > timeout {
+			panic("timed out waiting for vault dev server to start")
+		}
+
+		resp, err := client.Get(healthURL)
+		if err == nil && resp.StatusCode == http.StatusOK {
+			resp.Body.Close()
+			break
+		}
+		if resp != nil {
+			resp.Body.Close()
+		}
+
+		time.Sleep(200 * time.Millisecond)
+	}
+
 	return &vaultServer{
 		cmd: cmd,
 	}