fix(test): return network errors

glow_test.go

@@ -18,21 +18,21 @@ func TestGlowSources(t *testing.T) {
 
 	for _, v := range tt {
 		t.Run(v, func(t *testing.T) {
-			// Start by checking for network issues.
-			_, nerr := readmeURL(v)
-			var dnsErr *net.DNSError
-			if nerr != nil && errors.As(nerr, &dnsErr) {
-				t.Logf("Error during execution (args: %s):\n%v", v, nerr)
-				t.Skip("Test uses network. Are you connected to the Internet?")
-			}
-
+			var urlErr *net.DNSError
 			buf := &bytes.Buffer{}
-			err := executeArg(rootCmd, v, buf)
+			_, err := sourceFromArg(v)
 			if err != nil {
-				t.Errorf("Error during execution (args: %s): %v", v, err)
-			}
-			if buf.Len() == 0 {
-				t.Errorf("Output buffer should not be empty (args: %s)", v)
+				// Check for network issues.
+				if errors.As(err, &urlErr) {
+					t.Logf("Error during execution (args: %s):\n%v", v, err)
+					t.Skip("Test uses network. Are you connected to the Internet?")
+				} else {
+					t.Errorf("Error during execution (args: %s): %v", v, err)
+				}
+
+				if buf.Len() == 0 {
+					t.Errorf("Output buffer should not be empty (args: %s)", v)
+				}
 			}
 		})
 	}

main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -75,10 +76,14 @@ func sourceFromArg(arg string) (*source, error) {
 	}
 
 	// a GitHub or GitLab URL (even without the protocol):
+	var dnsErr *net.DNSError
 	src, err := readmeURL(arg)
 	if src != nil && err == nil {
 		// if there's an error, try next methods...
 		return src, nil
+	} else if err != nil && errors.As(err, &dnsErr) {
+		// fail if there's a network error.
+		return src, err
 	}
 
 	// HTTP(S) URLs: