use Context to send cancelation signals to groutines

README.md

@@ -45,7 +45,7 @@ import (
 )
 
 func main() {
-    for tweet := range twitterscraper.SearchTweets("twitter scraper data -filter:retweets", 50) {
+    for tweet := range twitterscraper.SearchTweets(context.Background(), "twitter scraper data -filter:retweets", 50) {
         if tweet.Error != nil {
             panic(tweet.Error)
         }

search.go

@@ -1,6 +1,7 @@
 package twitterscraper
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -10,13 +11,20 @@ import (
 const ajaxSearchURL = "https://twitter.com/i/search/timeline?q=%s"
 
 // SearchTweets returns channel with tweets for a given search query
-func SearchTweets(query string, maxTweetsNbr int) <-chan *Result {
+func SearchTweets(ctx context.Context, query string, maxTweetsNbr int) <-chan *Result {
 	channel := make(chan *Result)
 	go func(query string) {
 		defer close(channel)
 		var maxId string
 		tweetsNbr := 0
 		for tweetsNbr < maxTweetsNbr {
+			select {
+			case <-ctx.Done():
+				channel <- &Result{Error: ctx.Err()}
+				return
+			default:
+			}
+
 			tweets, err := FetchSearchTweets(query, maxId)
 			if err != nil {
 				channel <- &Result{Error: err}
@@ -28,9 +36,16 @@ func SearchTweets(query string, maxTweetsNbr int) <-chan *Result {
 			}
 
 			for _, tweet := range tweets {
+				select {
+				case <-ctx.Done():
+					channel <- &Result{Error: ctx.Err()}
+					return
+				default:
+				}
+
 				if tweetsNbr < maxTweetsNbr {
 					lastId, _ := strconv.ParseInt(tweet.ID, 10, 64)
-					maxId = strconv.FormatInt(lastId - 1, 10)
+					maxId = strconv.FormatInt(lastId-1, 10)
 					channel <- &Result{Tweet: *tweet}
 				}
 				tweetsNbr++

search_test.go

@@ -1,11 +1,14 @@
 package twitterscraper
 
-import "testing"
+import (
+	"context"
+	"testing"
+)
 
 func TestGetSearchTweets(t *testing.T) {
 	count := 0
 	maxTweetsNbr := 50
-	for tweet := range SearchTweets("twitter scraper data -filter:retweets", maxTweetsNbr) {
+	for tweet := range SearchTweets(context.Background(), "twitter scraper data -filter:retweets", maxTweetsNbr) {
 		if tweet.Error != nil {
 			t.Error(tweet.Error)
 		} else {

tweets.go

@@ -1,6 +1,7 @@
 package twitterscraper
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"regexp"
@@ -45,18 +46,32 @@ type Result struct {
 }
 
 // GetTweets returns channel with tweets for a given user.
-func GetTweets(user string, pages int) <-chan *Result {
+func GetTweets(ctx context.Context, user string, pages int) <-chan *Result {
 	channel := make(chan *Result)
 	go func(user string) {
 		defer close(channel)
 		var lastTweetID string
 		for pages > 0 {
+			select {
+			case <-ctx.Done():
+				channel <- &Result{Error: ctx.Err()}
+				return
+			default:
+			}
+
 			tweets, err := FetchTweets(user, lastTweetID)
 			if err != nil {
 				channel <- &Result{Error: err}
 				return
 			}
 			for _, tweet := range tweets {
+				select {
+				case <-ctx.Done():
+					channel <- &Result{Error: ctx.Err()}
+					return
+				default:
+				}
+
 				lastTweetID = tweet.ID
 				channel <- &Result{Tweet: *tweet}
 			}
@@ -103,7 +118,7 @@ func FetchTweets(user string, last string) ([]*Tweet, error) {
 	return tweets, nil
 }
 
-func readTweetsFromHTML (htm *strings.Reader) ([]*Tweet, error) {
+func readTweetsFromHTML(htm *strings.Reader) ([]*Tweet, error) {
 	var tweets []*Tweet
 
 	doc, err := goquery.NewDocumentFromReader(htm)

tweets_test.go

@@ -1,12 +1,13 @@
 package twitterscraper
 
 import (
+	"context"
 	"testing"
 )
 
 func TestGetTweets(t *testing.T) {
 	count := 0
-	for tweet := range GetTweets("nomadic_ua", 2) {
+	for tweet := range GetTweets(context.Background(), "nomadic_ua", 2) {
 		if tweet.Error != nil {
 			t.Error(tweet.Error)
 		} else {