refactor -- more go idiomatic

Author: xiahongze

gutils/scheduler.go

@@ -12,11 +12,12 @@ var SchdFreq = time.Minute * 1
 
 func init() {
 	if v, ok := os.LookupEnv("SCHEDULE_FREQ"); ok {
-		if vi, err := strconv.Atoi(v); err == nil {
-			SchdFreq = time.Minute * time.Duration(vi)
-		} else {
+		vi, err := strconv.Atoi(v)
+		if err != nil {
 			log.Println("WARN: SCHEDULE_FREQ is not int but ", v)
+			return
 		}
+		SchdFreq = time.Minute * time.Duration(vi)
 	}
 }
 

gutils/tasks.go

@@ -80,7 +80,8 @@ func processEntity(ent *models.Entity) {
 	if ent.Options.AlertType == "onChange" && content != last.Price {
 		subject := fmt.Sprintf("[%s] <%s> Alert: price changes to %s!", email.Identity, ent.Name, content)
 		ent.SendEmail(&subject)
-	} else if ent.Options.AlertType == "threshold" && ent.Options.Threshold >= float32(thisP) {
+	}
+	if ent.Options.AlertType == "threshold" && ent.Options.Threshold >= float32(thisP) {
 		subject := fmt.Sprintf("[%s] <%s> Alert: price drops to %s!", email.Identity, ent.Name, content)
 		ent.SendEmail(&subject)
 	}

handlers/create.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	"strings"
 
 	"github.com/labstack/echo"
 	"github.com/xiahongze/pricetracker/email"
@@ -30,21 +29,19 @@ func Create(c echo.Context) error {
 		ok      bool
 	)
 
+	if !req.Options.UseChrome {
+		content, ok = trackers.SimpleTracker(&req.URL, &req.XPATH)
+	}
+	if !ok {
+		req.Options.UseChrome = true
+		log.Println("INFO: Resorting to Chrome")
+	}
 	if req.Options.UseChrome {
 		if content, ok = trackers.ChromeTracker(&req.URL, &req.XPATH); !ok {
 			return c.String(http.StatusBadRequest, content)
 		}
-	} else {
-		if content, ok = trackers.SimpleTracker(&req.URL, &req.XPATH); !ok {
-			req.Options.UseChrome = true
-			log.Println("Resorting to Chrome")
-			if content, ok = trackers.ChromeTracker(&req.URL, &req.XPATH); !ok {
-				return c.String(http.StatusBadRequest, content)
-			}
-		}
 	}
 
-	content = strings.TrimSpace(content)
 	// check content as expected
 	if content != req.ExpectedPrice {
 		return c.String(http.StatusExpectationFailed,

models/entity.go

@@ -34,36 +34,33 @@ func (entity *Entity) Save(ctx context.Context, entTypName string, dsClient *dat
 	defer func() {
 		k, _ := json.Marshal(entity.K)
 		if err != nil {
-			log.Printf("ERROR: failed to save entity with %s\n", err)
-		} else {
-			log.Printf("INFO: saved K=%s\n", k)
+			log.Printf("ERROR: failed to save entity (K=%s) with %s\n", k, err)
+			return
 		}
+		log.Printf("INFO: saved K=%s\n", k)
 	}()
 
-	if entity.K == nil {
-		k := datastore.IncompleteKey(entTypName, nil)
-		var key *datastore.Key
-		key, err = dsClient.Put(ctx, k, entity)
-		if err != nil {
-			return err
-		}
-		entity.K = key
-	} else {
+	if entity.K != nil {
 		_, err = dsClient.Put(ctx, entity.K, entity)
-		if err != nil {
-			return err
-		}
+		return
 	}
-	return nil
+	entity.K = datastore.IncompleteKey(entTypName, nil)
+	entity.K, err = dsClient.Put(ctx, entity.K, entity)
+	if err != nil {
+		return
+	}
+
+	return
 }
 
 // SendEmail does what the name says
 func (entity *Entity) SendEmail(subject *string) {
-	if b, err := json.MarshalIndent(entity, "", "    "); err == nil {
-		if err := email.Send(string(b), *subject, entity.Options.Email); err != nil {
-			log.Print("failed to send email", err)
-		}
-	} else {
+	b, err := json.MarshalIndent(entity, "", "    ")
+	if err != nil {
 		log.Print("failed to marshal entity", err)
+		return
+	}
+	if err := email.Send(string(b), *subject, entity.Options.Email); err != nil {
+		log.Print("failed to send email", err)
 	}
 }

trackers/chrome_tracker.go

@@ -18,15 +18,16 @@ var (
 )
 
 func init() {
+	if v, ok := os.LookupEnv("CHROME_PATH"); ok {
+		chromePath = v
+	}
 	if v, ok := os.LookupEnv("CHROME_TIMEOUT"); ok {
-		if vi, err := strconv.Atoi(v); err == nil {
-			chromeTimeout = time.Second * time.Duration(vi)
-		} else {
+		vi, err := strconv.Atoi(v)
+		if err != nil {
 			log.Println("WARN: CHROME_TIMEOUT is not int but ", v)
+			return
 		}
-	}
-	if v, ok := os.LookupEnv("CHROME_PATH"); ok {
-		chromePath = v
+		chromeTimeout = time.Second * time.Duration(vi)
 	}
 }
 
@@ -35,17 +36,11 @@ func init() {
 func ChromeTracker(url, xpath *string) (string, bool) {
 	ctx, cancel := context.WithTimeout(context.Background(), chromeTimeout)
 	defer cancel()
-	var runnerOpt chromedp.Option
-	if chromePath == "" {
-		runnerOpt = chromedp.WithRunnerOptions(
-			runner.Flag("headless", true),
-		)
-	} else {
-		runnerOpt = chromedp.WithRunnerOptions(
-			runner.Path(chromePath),
-			runner.Flag("headless", true),
-		)
+	opts := []runner.CommandLineOption{runner.Flag("headless", true)}
+	if chromePath != "" {
+		opts = append(opts, runner.Path(chromePath))
 	}
+	runnerOpt := chromedp.WithRunnerOptions(opts...)
 
 	// create chrome instance
 	c, err := chromedp.New(ctx, runnerOpt)

trackers/simple_tracker.go

@@ -34,21 +34,21 @@ func SimpleTracker(url, xpath *string) (content string, ok bool) {
 	// create closure
 	extractHelper := func(reader io.Reader) {
 		xmlRoot, xmlErr := xmlpath.ParseHTML(reader)
-
 		if xmlErr != nil {
 			content = "ERROR: parse xml error: " + xmlErr.Error()
 			log.Println(content)
 			ok = false
 			return
 		}
-		if value, found := xpExec.String(xmlRoot); found {
-			log.Println("INFO: Found", value, "from", *url)
-			content = value
-			ok = true
-		} else {
+		value, found := xpExec.String(xmlRoot)
+		if !found {
 			ok = false
 			content = "value not found"
+			return
 		}
+		log.Println("INFO: Found", value, "from", *url)
+		content = value
+		ok = true
 	}
 
 	// step 1. read directly from body