modify git blame url to use public base url without api prefix

internal/pkg/githubapi/drift_detection.go

@@ -52,8 +52,7 @@ func generateDiffOutput(ghPrClientDetails GhPrClientDetails, defaultBranch strin
 
 	if len(filesWithDiff) != 0 {
 		diffOutput.WriteString("\n### Blame Links:\n")
-		githubURL := ghPrClientDetails.GhClientPair.v3Client.BaseURL.String()
-		blameUrlPrefix := githubURL + ghPrClientDetails.Owner + "/" + ghPrClientDetails.Repo + "/blame"
+		blameUrlPrefix := ghPrClientDetails.getBlameURLPrefix()
 
 		for _, f := range filesWithDiff {
 			diffOutput.WriteString("[" + f + "](" + blameUrlPrefix + "/HEAD/" + f + ")\n") // TODO consider switching HEAD to specific SHA

internal/pkg/githubapi/drift_detection_test.go

@@ -128,7 +128,7 @@ func TestGenerateDiffOutputDiffFileContent(t *testing.T) {
 @@ -1 +1 @@
 -File A content
 +File B content` + "\n\n```\n\n" + `### Blame Links:
-[source-path/file-1.text](https://api.github.com/AnOwner/Arepo/blame/HEAD/source-path/file-1.text)
+[source-path/file-1.text](https://github.com/AnOwner/Arepo/blame/HEAD/source-path/file-1.text)
 `
 
 	var sourceFilesSHAs map[string]string

internal/pkg/githubapi/github.go

@@ -28,7 +28,10 @@ import (
 	"golang.org/x/exp/maps"
 )
 
-const githubCommentMaxSize = 65536
+const (
+	githubCommentMaxSize = 65536
+	githubPublicBaseURL  = "https://github.com"
+)
 
 type DiffCommentData struct {
 	DiffOfChangedComponents []argocd.DiffResult
@@ -93,6 +96,14 @@ func (ghPrClientDetails *GhPrClientDetails) getPrMetadata(prBody string) {
 	}
 }
 
+func (ghPrClientDetails *GhPrClientDetails) getBlameURLPrefix() string {
+	githubHost := getEnv("GITHUB_HOST", "")
+	if githubHost == "" {
+		githubHost = githubPublicBaseURL
+	}
+	return fmt.Sprintf("%s/%s/%s/blame", githubHost, ghPrClientDetails.Owner, ghPrClientDetails.Repo)
+}
+
 func HandlePREvent(eventPayload *github.PullRequestEvent, ghPrClientDetails GhPrClientDetails, mainGithubClientPair GhClientPair, approverGithubClientPair GhClientPair, ctx context.Context) {
 	ghPrClientDetails.getPrMetadata(eventPayload.PullRequest.GetBody())
 	// wasCommitStatusSet and the placement of SetCommitStatus in the flow is used to ensure an API call is only made where it needed

internal/pkg/githubapi/github_test.go

@@ -3,6 +3,7 @@ package githubapi
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"os"
 	"testing"
 
@@ -251,3 +252,36 @@ func TestPrBody(t *testing.T) {
 	}
 	assert.Equal(t, string(expectedPrBody), newPrBody)
 }
+
+func TestGhPrClientDetailsGetBlameURLPrefix(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		Host      string
+		Owner     string
+		Repo      string
+		ExpectURL string
+	}{
+		{
+			"",
+			"commercetools",
+			"test",
+			fmt.Sprintf("%s/commercetools/test/blame", githubPublicBaseURL),
+		},
+		{
+			"https://myserver.github.com",
+			"some-other-owner",
+			"some-other-repo",
+			"https://myserver.github.com/some-other-owner/some-other-repo/blame",
+		},
+	}
+
+	// reset the GITHUB_HOST env to prevent conflicts with other tests.
+	defer os.Unsetenv("GITHUB_HOST")
+
+	for _, tc := range tests {
+		os.Setenv("GITHUB_HOST", tc.Host)
+		ghPrClientDetails := &GhPrClientDetails{Owner: tc.Owner, Repo: tc.Repo}
+		blameURLPrefix := ghPrClientDetails.getBlameURLPrefix()
+		assert.Equal(t, tc.ExpectURL, blameURLPrefix)
+	}
+}