better error handle way and add test case for failure

downmark.go

@@ -6,7 +6,6 @@ import (
 	"net/url"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"golang.org/x/net/html"
@@ -110,35 +109,40 @@ func (d DLink) Convert(h HandlerFunc) (Conversion, error) {
 		Timeout: timeOut,
 	}
 
-	var successCounter int64
-	var failCounter int64
+	var totalCount int
+	var successCounter int
 
 	for i, u := range d {
 		go func(id int, url string) {
 			resp, err := client.Get(url)
 
 			if err != nil {
-				fmt.Println(url + "FAIL in request")
-				atomic.AddInt64(&failCounter, 1)
+				fmt.Println("FAIL in request --> " + url)
+
+				failure := newDBody(id, nil)
+				tokenizerChan <- &failure
+
 				return
 			}
 
 			defer resp.Body.Close()
 
 			dBody := newDBody(id, html.NewTokenizer(resp.Body))
-
-			atomic.AddInt64(&successCounter, 1)
-
 			tokenizerChan <- &dBody
 		}(i, u)
 	}
 
 	for dy := range tokenizerChan {
-		if atomic.LoadInt64(&successCounter)+atomic.LoadInt64(&failCounter) == int64(len(d)) {
+		totalCount++
+
+		if totalCount == len(d) {
 			close(tokenizerChan)
 		}
 
-		go h(newConverted(dy.Index), dy.ParsedBody, convertedChan)
+		if dy.ParsedBody != nil {
+			successCounter++
+			go h(newConverted(dy.Index), dy.ParsedBody, convertedChan)
+		}
 	}
 
 	for successCounter > 0 {

downmark_test.go

@@ -45,19 +45,41 @@ func exampleFunc(cv *Converted, tr *html.Tokenizer, ch chan *Converted) {
 func Test_handler(t *testing.T) {
 	d := NewDLink()
 
-	d.AddLink("http://www.google.com")
+	d.AddLink("://www.google.com")
 	d.AddLink("http://www.youtube.com")
 	d.AddLink("https://www.washingtonpost.com/")
 
 	cv, _ := d.Convert(exampleFunc)
 	var testStr string
 
-	for i := 0; i < 3; i++ {
-		s := *(cv[string(i)].data)
-		testStr += s[0]
+	for i := 0; i < len(d); i++ {
+		c, contains := cv[string(i)]
+
+		if contains {
+			s := *c.data
+			testStr += s[0]
+		}
 	}
 
 	if testStr != "abc" {
 		t.Errorf("Expected 'abc' but got '%v' ", testStr)
 	}
 }
+
+func Test_failure(t *testing.T) {
+	d := NewDLink()
+
+	d.AddLink("://www.nkvxxnvhh.com")
+	d.AddLink("http://youtouneaube.com")
+	d.AddLink("https://www.waffawshinnjbgtonpost.com/")
+
+	cv, _ := d.Convert(exampleFunc)
+
+	for i := 0; i < len(d); i++ {
+		_, contains := cv[string(i)]
+		t.Log("Expected ALL fail when request")
+		if contains {
+			t.Errorf("It should be no any index key in it when every request fail")
+		}
+	}
+}