F/fix test suite (#3)

* chore: add debug

* chore: print error saving file

* chore: add path 2 log

* chore: add rename err

* fix: only rename once

* chore: return error when readFile() and copyFile() returns error

mongobin/getOrDownload.go

@@ -33,6 +33,11 @@ func init() {
 // at the given URL. If the URL has not yet been downloaded, it's downloaded
 // and saved the the cache. If it has been downloaded, the existing mongod
 // path is returned.
+/*
+Flow: URL (download url) -> check existence
+	exist: return mongo path
+	non-exist: http download -> save bin/mongod
+*/
 func GetOrDownloadMongod(urlStr string, cachePath string, logger *memongolog.Logger) (string, error) {
 	dirname, dirErr := directoryNameForURL(urlStr)
 	if dirErr != nil {
@@ -156,11 +161,11 @@ func saveFile(mongodPath string, tarReader *tar.Reader, logger *memongolog.Logge
 
 			content, err := Afs.ReadFile(mongodTmpFile.Name())
 			if err != nil {
-				fmt.Println("ERROR:", err)
+				return fmt.Errorf("read file err: %w", err)
 			}
 			_, copyErr := mongodFile.Write(content)
 			if copyErr != nil {
-				fmt.Errorf("error copying mongod binary from %s to %s: %s", mongodTmpFile.Name(), mongodPath, copyErr)
+				return fmt.Errorf("error copying mongod binary from %s to %s: %w", mongodTmpFile.Name(), mongodPath, copyErr)
 			}
 		}
 	}

mongobin/getOrDownload_test.go

@@ -53,14 +53,13 @@ func TestGetOrDownload(t *testing.T) {
 }
 
 func TestGetOrDownloadDifferentFilesystems(t *testing.T) {
-
 	FS := afero.NewMemMapFs() // afero.NewOsFs()
 
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
 	m := mockAfero.NewMockFs(ctrl)
 
-	m.EXPECT().Rename(gomock.Any(), gomock.Any()).Return(&os.LinkError{"rename", "oldname", "newname", errors.New("rename error")}).Times(2)
+	m.EXPECT().Rename(gomock.Any(), gomock.Any()).Return(&os.LinkError{"rename", "oldname", "newname", errors.New("rename error")}).Times(1)
 
 	// General mock faking :)
 	m.EXPECT().Mkdir(gomock.Any(), gomock.Any()).DoAndReturn(func(dir string, perm fs.FileMode) error { return FS.Mkdir(dir, perm) }).AnyTimes()