Move link file creation up to avoid bugs with file being truncated.

cmd/main.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"path"
 	"strings"
 	"time"
 
@@ -98,11 +99,22 @@ func run() {
 		logger = ioutil.Discard
 	}
 
+	var linksFile *os.File
+	if saveLinks {
+		linksFile, err = os.Create(path.Join(saveDir.Path, "links.txt"))
+		if err != nil {
+			log.Fatalf("could not create links file: %s", err)
+		}
+		defer linksFile.Close()
+		fmt.Printf("%+v\n", linksFile)
+	}
+
 	saver := &saver.TweetSaver{
 		SaveDir:   saveDir.Path,
 		SaveJson:  saveJson,
 		SaveMedia: saveMedia,
 		SaveLinks: saveLinks,
+		LinksFile: linksFile,
 	}
 
 	client := getTwitterClient(consumerKey, consumerSecret, accessToken, accessTokenSecret)

pkg/saver/saver.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path"
 	"strconv"
+	"strings"
 	"sync"
 
 	"golang.org/x/sync/errgroup"
@@ -19,6 +20,7 @@ type TweetSaver struct {
 	SaveJson  bool
 	SaveMedia bool
 	SaveLinks bool
+	LinksFile *os.File
 }
 
 func (ts *TweetSaver) Save(tweets []twitter.Tweet) error {
@@ -71,14 +73,13 @@ func (ts *TweetSaver) Save(tweets []twitter.Tweet) error {
 			close(links)
 		}()
 
-		file, err := makeLinks(path.Join(ts.SaveDir, "links.txt"))
-		if err != nil {
-			return err
+		var sb strings.Builder
+		for link := range links {
+			sb.WriteString(link + "\n")
 		}
-		defer file.Close()
 
-		for link := range links {
-			file.WriteString(link + "\n")
+		if _, err := ts.LinksFile.WriteString(sb.String()); err != nil {
+			return fmt.Errorf("could not save links: %s", err)
 		}
 	}
 
@@ -139,12 +140,3 @@ func makeDir(dest string) error {
 
 	return nil
 }
-
-func makeLinks(dest string) (*os.File, error) {
-	file, err := os.OpenFile(dest, os.O_CREATE|os.O_APPEND|os.O_TRUNC|os.O_WRONLY, 0744)
-	if err != nil {
-		return nil, fmt.Errorf("could not create links file: %s", err)
-	}
-
-	return file, nil
-}

pkg/saver/saver_test.go

@@ -109,12 +109,16 @@ func TestTweetSaverSaveLinks(t *testing.T) {
 		},
 	}
 
+	file, err := os.OpenFile("./output/links.txt", os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0744)
+	is.NoErr(err)
+
 	saver := TweetSaver{
 		SaveDir:   "./output",
 		SaveLinks: true,
+		LinksFile: file,
 	}
 
-	err := saver.Save([]twitter.Tweet{tweet})
+	err = saver.Save([]twitter.Tweet{tweet})
 	is.NoErr(err)
 
 	fbytes, _ := ioutil.ReadFile("./fixtures/links.txt")