translations: imp code, docs

Author: EugeneOne1

scripts/README.md

@@ -228,7 +228,7 @@ Optional environment:
 
 - `TWOSKY_PROJECT_ID`: set an alternative project ID for `download` or `upload`.
 
-  Deprectated: This environment variable should not be used since the script began supporting multiple configurations.
+    Deprectated: This environment variable should not be used since the script began supporting multiple configurations.
 
 ## `companiesdb/`: Whotracks.me database converter
 

scripts/translations/download.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"bytes"
 	"context"
 	"flag"
 	"fmt"
@@ -20,26 +19,14 @@ import (
 	"github.com/AdguardTeam/golibs/logutil/slogutil"
 	"github.com/AdguardTeam/golibs/netutil"
 	"github.com/AdguardTeam/golibs/syncutil"
+	"github.com/AdguardTeam/golibs/validate"
 )
 
 // download and save all translations.
-func (c *twoskyClient) download(ctx context.Context, l *slog.Logger) (err error) {
-	var numWorker int
-
-	flagSet := flag.NewFlagSet("download", flag.ExitOnError)
-	flagSet.Usage = func() {
-		usage("download command error")
-	}
-	flagSet.IntVar(&numWorker, "n", 1, "number of concurrent downloads")
-
-	err = flagSet.Parse(os.Args[2:])
+func (c *twoskyClient) download(ctx context.Context, l *slog.Logger) {
+	numWorker, err := parseDownloadArgs()
 	if err != nil {
-		// Don't wrap the error since it's informative enough as is.
-		return err
-	}
-
-	if numWorker < 1 {
-		usage("count must be positive")
+		usage(err.Error())
 	}
 
 	downloadURI := c.uri.JoinPath("download")
@@ -62,8 +49,7 @@ func (c *twoskyClient) download(ctx context.Context, l *slog.Logger) (err error)
 	}
 
 	for _, baseFile := range c.localizableFiles {
-		file := filepath.Base(baseFile)
-		dir := filepath.Dir(baseFile)
+		dir, file := filepath.Split(baseFile)
 
 		for _, lang := range c.langs {
 			uri := translationURL(downloadURI, file, c.projectID, lang)
@@ -79,8 +65,20 @@ func (c *twoskyClient) download(ctx context.Context, l *slog.Logger) (err error)
 	wg.Wait()
 
 	printFailedLocales(ctx, l, dw.failed)
+}
 
-	return nil
+// parseDownloadArgs parses command-line arguments for the download command.
+func parseDownloadArgs() (numWorker int, err error) {
+	flagSet := flag.NewFlagSet("download", flag.ExitOnError)
+	flagSet.IntVar(&numWorker, "n", 1, "number of concurrent downloads")
+
+	err = flagSet.Parse(os.Args[2:])
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return 0, err
+	}
+
+	return numWorker, validate.Positive("count", numWorker)
 }
 
 // printFailedLocales prints sorted list of failed downloads, if any.  l and
@@ -137,9 +135,6 @@ func (w *downloadWorker) run() {
 	}
 }
 
-// newLineSuffix is the suffix required for each text file.
-var newLineSuffix = []byte("\n")
-
 // saveToFile downloads translation by url and saves it to a file, or returns
 // error.
 func saveToFile(
@@ -155,8 +150,8 @@ func saveToFile(
 		return fmt.Errorf("getting translation %q: %s", code, err)
 	}
 
-	if !bytes.HasSuffix(data, newLineSuffix) {
-		data = append(data, newLineSuffix...)
+	if data[len(data)-1] != '\n' {
+		data = append(data, '\n')
 	}
 
 	name := filepath.Join(localesDir, code+".json")
@@ -171,7 +166,8 @@ func saveToFile(
 }
 
 // getTranslation returns received translation data and error.  If err is not
-// nil, data may contain a response from server for inspection.
+// nil, data may contain a response from server for inspection.  Otherwise, the
+// data is guaranteed to be non-empty.
 func getTranslation(
 	ctx context.Context,
 	l *slog.Logger,
@@ -194,8 +190,11 @@ func getTranslation(
 	limitReader := ioutil.LimitReader(resp.Body, readLimit.Bytes())
 
 	data, readErr := io.ReadAll(limitReader)
+	if readErr != nil {
+		return nil, errors.WithDeferred(err, readErr)
+	}
 
-	return data, errors.WithDeferred(err, readErr)
+	return data, validate.NotEmptySlice("response", data)
 }
 
 // translationURL returns a new url.URL with provided query parameters.

scripts/translations/main.go

@@ -86,10 +86,10 @@ func main() {
 		errors.Check(summary(homeConf.Languages))
 	case "download":
 		cli = errors.Must(newTwoskyClient(homeConf))
-		errors.Check(cli.download(ctx, l))
+		cli.download(ctx, l)
 
 		cli = errors.Must(newTwoskyClient(servicesConf))
-		errors.Check(cli.download(ctx, l))
+		cli.download(ctx, l)
 	case "unused":
 		errors.Check(unused(ctx, l, homeConf.LocalizableFiles[0]))
 	case "upload":