Fix links for deps with tag that contains one slash

Author: willie-yao

pkg/modiff/modiff.go

@@ -2,8 +2,10 @@ package modiff
 
 import (
 	"bufio"
+	"context"
 	"errors"
 	"fmt"
+	"net/http"
 	"os"
 	"os/exec"
 	"slices"
@@ -216,7 +218,14 @@ func getModules(workDir, from, to string) (modules, error) {
 			linkPrefix := name
 			// Remove the module name from the link
 			if splitLink := strings.Split(linkPrefix, "/"); len(splitLink) == 4 {
-				linkPrefix = strings.Join(splitLink[:3], "/")
+				// Check if the last part of string is part of the tag.
+				linkPrefixTree := strings.Join(slices.Insert(splitLink, 3, "tree"), "/")
+				url := fmt.Sprintf("https://%s%s%s", linkPrefixTree, "/", strings.TrimSpace(split[1]))
+				// If the url is valid, then we keep the linkPrefix as is
+				client := http.Client{}
+				if valid, err := CheckURLValid(client, url); !valid && err == nil {
+					linkPrefix = strings.Join(splitLink[:3], "/")
+				}
 			}
 			version := strings.TrimSpace(split[1])
 
@@ -251,6 +260,25 @@ func getModules(workDir, from, to string) (modules, error) {
 	return res, nil
 }
 
+func CheckURLValid(client http.Client, url string) (bool, error) {
+	ctx := context.Background()
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, http.NoBody)
+	if err != nil {
+		return false, fmt.Errorf("error while creating request: %w", err)
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return false, fmt.Errorf("error while sending request: %w", err)
+	} else if resp.StatusCode == http.StatusNotFound {
+		resp.Body.Close()
+
+		return false, nil
+	}
+	resp.Body.Close()
+
+	return true, nil
+}
+
 func retrieveModules(rev, workDir string) (string, error) {
 	logrus.Infof("Retrieving modules of %s", rev)
 	if err := runGit(

pkg/modiff/modiff_test.go

@@ -2,6 +2,11 @@ package modiff_test
 
 //nolint:revive // test file
 import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 	"github.com/saschagrunert/go-modiff/pkg/modiff"
@@ -42,9 +47,10 @@ _Nothing has changed._
 `
 
 	const (
-		repo = "github.com/saschagrunert/go-modiff"
-		from = "v0.10.0"
-		to   = "v0.11.0"
+		repo    = "github.com/saschagrunert/go-modiff"
+		from    = "v0.10.0"
+		to      = "v0.11.0"
+		badRepo = "github.com/saschagrunert/go-modiff-invalid"
 	)
 
 	BeforeEach(func() {
@@ -120,4 +126,71 @@ _Nothing has changed._
 		Expect(err).To(HaveOccurred())
 		Expect(res).To(BeEmpty())
 	})
+
+	It("should fail if the repository url is invalid", func() {
+		// Given
+		config := modiff.NewConfig(badRepo, from, to, true, 1)
+
+		// When
+		res, err := modiff.Run(config)
+
+		// Then
+		Expect(err).To(HaveOccurred())
+		Expect(res).To(BeEmpty())
+	})
 })
+
+func TestCheckURLValid(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name     string
+		url      string
+		expected bool
+		err      error
+		client   *http.Client
+	}{
+		{
+			name:     "Valid URL",
+			url:      "https://github.com/hashicorp/consul/compare/api/v1.18.0...api/v1.20.0",
+			expected: true,
+			err:      nil,
+		},
+		{
+			name:     "Invalid URL",
+			url:      "https://github.com/hashicorp/consul/compare/v1.18.0...v1.20.0",
+			expected: false,
+			err:      nil,
+		},
+		{
+			name:     "Request Sending Error",
+			url:      "invalid-url",
+			expected: false,
+			err:      fmt.Errorf("error while sending request: "),
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			g := NewGomegaWithT(t)
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(http.StatusNotFound)
+			}))
+			defer server.Close()
+
+			if tt.client == nil {
+				tt.client = &http.Client{}
+			}
+			valid, err := modiff.CheckURLValid(*tt.client, tt.url)
+			g.Expect(valid).To(Equal(tt.expected))
+			if tt.err != nil {
+				g.Expect(err).To(HaveOccurred())
+				g.Expect(err.Error()).To(ContainSubstring(tt.err.Error()))
+			} else {
+				g.Expect(err).ToNot(HaveOccurred())
+			}
+		})
+	}
+}