Handle URL resolution errors properly

Do not panic right away when an URL fails to resolve. Capture the error and make it visible in the statistic. The change also treats the fail CLI options properly so that the programs fails after all links have been processed independent of the outcome.

file/file_test.go

@@ -108,6 +108,13 @@ func TestReadFile(t *testing.T) {
 	deleteFile(path1)
 }
 
+func TestPanicWhenReadingNonExistentFile(t *testing.T) {
+	path := filepath.Join("1.adoc")
+	Panics(t, func() {
+		ReadFile(path)
+	})
+}
+
 func createDir(path string) {
 	err := os.MkdirAll(path, 0755)
 

http/http.go

@@ -16,24 +16,26 @@ func SetTimeout(timeout int) {
 // Get emits a HTTP GET request for a given URL. Captures the status code, status and outcome of the call.
 // Returns with information about the response.
 func Get(link string) HttpResponse {
-	result := HttpResponse{Url: link, Success: true}
+	result := HttpResponse{Url: link}
 	url, err := url.ParseRequestURI(link)
 
 	if err != nil {
-		panic(err)
+		result.Error = err
+		return result
 	}
 
 	resp, err := client.Get(url.String())
 
 	if err != nil {
-		panic(err)
+		result.Error = err
+		return result
 	}
 
 	result.StatusCode = resp.StatusCode
 	result.Status = resp.Status
 
-	if resp.StatusCode != 200 {
-		result.Success = false
+	if resp.StatusCode == 200 {
+		result.Success = true
 	}
 
 	resp.Body.Close()
@@ -46,4 +48,5 @@ type HttpResponse struct {
 	Success    bool
 	StatusCode int
 	Status     string
+	Error      error
 }

http/http_test.go

@@ -6,27 +6,44 @@ import (
 	"testing"
 )
 
+func TestSetTimeout(t *testing.T) {
+	SetTimeout(20)
+}
+
 func TestGetValidUrl(t *testing.T) {
 	url := "http://www.google.com/"
 	result := Get(url)
 
 	Equal(t, url, result.Url)
 	True(t, result.Success)
+	Nil(t, result.Error)
 	Equal(t, 200, result.StatusCode)
 }
 
+func TestGetUrlForBadRequest(t *testing.T) {
+	url := "https://www.googleapis.com/urlshortener/v1/url"
+	result := Get(url)
+
+	Equal(t, url, result.Url)
+	False(t, result.Success)
+	Nil(t, result.Error)
+	Equal(t, 400, result.StatusCode)
+}
+
 func TestGetNonExistentUrl(t *testing.T) {
 	url := "http://www.unknown1x.com/"
-	Panics(t, func() {
-		Get(url)
-	})
+	result := Get(url)
+
+	Equal(t, url, result.Url)
+	False(t, result.Success)
+	NotNil(t, result.Error)
 }
 
-func TestGetUrlForBadRequest(t *testing.T) {
-	url := "https://www.googleapis.com/urlshortener/v1/url"
+func TestGetInvalidUrl(t *testing.T) {
+	url := "123://www.invalid.com/"
 	result := Get(url)
 
 	Equal(t, url, result.Url)
 	False(t, result.Success)
-	Equal(t, 400, result.StatusCode)
+	NotNil(t, result.Error)
 }

stat/stat.go

@@ -20,6 +20,16 @@ func SumFailures(aggregateSummary []Summary) int {
 	return sum(failures)
 }
 
+// SumErrors sums up all errors.
+// Returns the overall number of errors.
+func SumErrors(aggregateSummary []Summary) int {
+	errors := collect(aggregateSummary, func(summary Summary) int {
+		return summary.Errored
+	})
+
+	return sum(errors)
+}
+
 func collect(list []Summary, f convert) []int {
 	result := make([]int, len(list))
 
@@ -46,4 +56,5 @@ type convert func(Summary) int
 type Summary struct {
 	Successful int
 	Failed     int
+	Errored    int
 }

stat/stat_test.go

@@ -15,7 +15,7 @@ func TestSumSuccessesForEmptySlice(t *testing.T) {
 func TestSumSuccessesForPopulatedSlice(t *testing.T) {
 	aggregateSummary := summaries()
 	sum := SumSuccesses(aggregateSummary)
-	Equal(t, 29, sum)
+	Equal(t, 41, sum)
 }
 
 func TestSumFailuresForEmptySlice(t *testing.T) {
@@ -30,10 +30,23 @@ func TestSumFailuresForPopulatedSlice(t *testing.T) {
 	Equal(t, 70, sum)
 }
 
+func TestSumErrorsForEmptySlice(t *testing.T) {
+	aggregateSummary := []Summary{}
+	sum := SumErrors(aggregateSummary)
+	Equal(t, 0, sum)
+}
+
+func TestSumErrorsForPopulatedSlice(t *testing.T) {
+	aggregateSummary := summaries()
+	sum := SumErrors(aggregateSummary)
+	Equal(t, 2, sum)
+}
+
 func summaries() []Summary {
 	summaries := []Summary{}
 	summaries = append(summaries, Summary{Successful: 20, Failed: 3})
 	summaries = append(summaries, Summary{Successful: 7, Failed: 67})
 	summaries = append(summaries, Summary{Successful: 2, Failed: 0})
+	summaries = append(summaries, Summary{Successful: 12, Failed: 0, Errored: 2})
 	return summaries
 }

verify/verify.go

@@ -49,12 +49,13 @@ func Process(files []string, fail bool) {
 	if len(aggregateSummary) > 0 {
 		successCount := stat.SumSuccesses(aggregateSummary)
 		failureCount := stat.SumFailures(aggregateSummary)
-		stats := fmt.Sprintf("SUCCESSFUL: %s, FAILED: %s", strconv.Itoa(successCount), strconv.Itoa(failureCount))
+		errorCount := stat.SumErrors(aggregateSummary)
+		stats := fmt.Sprintf("SUCCESSFUL: %s, FAILED: %s, ERRORED: %s", strconv.Itoa(successCount), strconv.Itoa(failureCount), strconv.Itoa(errorCount))
 		fmt.Println()
 		fmt.Println(calculateSeparator(stats))
 		fmt.Println(stats)
 
-		if failureCount > 0 && !fail {
+		if (failureCount > 0 || errorCount > 0) && !fail {
 			os.Exit(1)
 		}
 	}
@@ -84,7 +85,10 @@ func parseLinks(content string) stat.Summary {
 func validateLink(link string, summary *stat.Summary, ch chan<- string) {
 	response := http.Get(link)
 
-	if response.Success {
+	if response.Error != nil {
+		summary.Errored++
+		ch <- fmt.Sprintf("[ERROR] %s (%s)", link, response.Error.Error())
+	} else if response.Success {
 		summary.Successful++
 		ch <- fmt.Sprintf("[OK] %s", link)
 	} else {