Add a test for cmd/generate-config.

Veriying the generated configuration.

global.jetstream.addresses is required in polylith mode. Adding a
dummy value for CI.

cmd/generate-config/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"os"
 	"path/filepath"
 
 	"github.com/matrix-org/dendrite/setup/config"
@@ -12,13 +13,31 @@ import (
 )
 
 func main() {
-	defaultsForCI := flag.Bool("ci", false, "Populate the configuration with sane defaults for use in CI")
-	serverName := flag.String("server", "", "The domain name of the server if not 'localhost'")
-	dbURI := flag.String("db", "", "The DB URI to use for all components (PostgreSQL only)")
-	dirPath := flag.String("dir", "./", "The folder to use for paths (like SQLite databases, media storage)")
-	normalise := flag.String("normalise", "", "Normalise an existing configuration file by adding new/missing options and defaults")
-	polylith := flag.Bool("polylith", false, "Generate a config that makes sense for polylith deployments")
-	flag.Parse()
+	cfg, err := buildConfig(flag.CommandLine, os.Args[1:])
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	bs, err := yaml.Marshal(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(string(bs))
+}
+
+func buildConfig(fs *flag.FlagSet, args []string) (*config.Dendrite, error) {
+	defaultsForCI := fs.Bool("ci", false, "Populate the configuration with sane defaults for use in CI")
+	serverName := fs.String("server", "", "The domain name of the server if not 'localhost'")
+	dbURI := fs.String("db", "", "The DB URI to use for all components (PostgreSQL only)")
+	dirPath := fs.String("dir", "./", "The folder to use for paths (like SQLite databases, media storage)")
+	normalise := fs.String("normalise", "", "Normalise an existing configuration file by adding new/missing options and defaults")
+	polylith := fs.Bool("polylith", false, "Generate a config that makes sense for polylith deployments")
+
+	if err := fs.Parse(args); err != nil {
+		return nil, err
+	}
 
 	var cfg *config.Dendrite
 	if *normalise == "" {
@@ -95,6 +114,9 @@ func main() {
 			cfg.UserAPI.BCryptCost = bcrypt.MinCost
 			cfg.Global.JetStream.InMemory = true
 			cfg.Global.JetStream.StoragePath = config.Path(*dirPath)
+			if *polylith {
+				cfg.Global.JetStream.Addresses = []string{"localhost"}
+			}
 			cfg.ClientAPI.RegistrationDisabled = false
 			cfg.ClientAPI.OpenRegistrationWithoutVerificationEnabled = true
 			cfg.ClientAPI.RegistrationSharedSecret = "complement"
@@ -106,14 +128,9 @@ func main() {
 	} else {
 		var err error
 		if cfg, err = config.Load(*normalise, !*polylith); err != nil {
-			panic(err)
+			return nil, err
 		}
 	}
 
-	j, err := yaml.Marshal(cfg)
-	if err != nil {
-		panic(err)
-	}
-
-	fmt.Println(string(j))
+	return cfg, nil
 }

cmd/generate-config/main_test.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"flag"
+	"testing"
+
+	"github.com/matrix-org/dendrite/setup/config"
+)
+
+func TestBuildConfig(t *testing.T) {
+	tsts := []struct {
+		Name       string
+		Args       []string
+		IsMonolith bool
+	}{
+		{"ciMonolith", []string{"-ci"}, true},
+		{"ciPolylith", []string{"-ci", "-polylith"}, false},
+	}
+	for _, tst := range tsts {
+		t.Run(tst.Name, func(t *testing.T) {
+			cfg, err := buildConfig(flag.NewFlagSet("main_test", flag.ContinueOnError), tst.Args)
+			if err != nil {
+				t.Fatalf("buildConfig failed: %v", err)
+			}
+
+			var ss config.ConfigErrors
+			cfg.Verify(&ss, tst.IsMonolith)
+			for _, s := range ss {
+				t.Errorf("Verify: %s", s)
+			}
+		})
+	}
+}