better testing

cmd/roaring-migrate/main.go

@@ -29,6 +29,10 @@ const (
 )
 
 func main() {
+	os.Exit(realMain())
+}
+func realMain() int {
+
 	visited = make(map[string]int64)
 	var dataDir, backupPath string
 	var verbose bool
@@ -54,14 +58,12 @@ func main() {
 	err := cmdMigrate.MarkFlagRequired("data-dir")
 	if err != nil {
 		fmt.Println("Error setting flag data-dir")
-		os.Exit(1)
-		return
+		return 1
 	}
 	err = cmdMigrate.MarkFlagRequired("backup-dir")
 	if err != nil {
 		fmt.Println("Error setting flag backup-dir")
-		os.Exit(1)
-		return
+		return 1
 	}
 	if verbose {
 		vprint.VV("Version: %v", Version)
@@ -70,8 +72,9 @@ func main() {
 	err = cmdMigrate.Execute()
 	if err != nil {
 		fmt.Println("exec error", err)
-		os.Exit(1)
+		return 1
 	}
+	return 0
 }
 
 func FetchFragments(base string) []string {

cmd/roaring-migrate/main_test.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func TestFileExists(t *testing.T) {
+	fileName := "missing"
+	if x, _ := fileExists(fileName); x {
+		t.Fatalf("file %v doesn't exist", fileName)
+	}
+	file, err := os.Create(fileName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	file.Close()
+
+	if x, _ := fileExists(fileName); !x {
+		t.Fatalf("file %v doesn't exist", fileName)
+	}
+
+	t.Cleanup(func() {
+		os.Remove(fileName)
+	})
+}
+
+func TestMainProgram(t *testing.T) {
+	os.Args = []string{"roaring-migrate",
+		"--verbose",
+	}
+	if realMain() == 0 {
+		t.Fatal("should fail and it succeeded")
+	}
+	dir, err := ioutil.TempDir("", "backup")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir) // clean up
+	os.Args = []string{"roaring-migrate",
+		"--verbose",
+		"--data-dir=testdata/data-dir/",
+		"--backup-dir=" + dir,
+	}
+	if realMain() == 1 {
+		t.Fatal("shouldn't fail")
+	}
+
+}

cmd/roaring-migrate/testdata/data-dir/.id

@@ -0,0 +1 @@
+6fc20f49-edf3-4211-8f6d-c670258ee6ea

cmd/roaring-migrate/testdata/data-dir/.startup.log

@@ -0,0 +1 @@
+2022-02-14T11:49:34.20065623-06:00	v2.7.0

cmd/roaring-migrate/testdata/data-dir/.topology

@@ -0,0 +1,2 @@
+
+$a317bd70-60ed-4723-99fa-3067563a708e$6fc20f49-edf3-4211-8f6d-c670258ee6ea

cmd/roaring-migrate/testdata/data-dir/repository/.meta

@@ -0,0 +1 @@
+