Use "concise" diff comment in cases "regular" diff comment is > 65536 (…

…#20)

internal/pkg/githubapi/github.go

@@ -28,6 +28,8 @@ import (
 	"golang.org/x/exp/maps"
 )
 
+const githubCommentMaxSize = 65536
+
 type promotionInstanceMetaData struct {
 	SourcePath  string   `json:"sourcePath"`
 	TargetPaths []string `json:"targetPaths"`
@@ -186,12 +188,20 @@ func HandlePREvent(eventPayload *github.PullRequestEvent, ghPrClientDetails GhPr
 				err, templateOutput := executeTemplate(ghPrClientDetails.PrLogger, "argoCdDiff", "argoCD-diff-pr-comment.gotmpl", diffCommentData)
 				if err != nil {
 					prHandleError = err
-					log.Errorf("Failed to generate ArgoCD diff comment template: err=%s\n", err)
+					ghPrClientDetails.PrLogger.Errorf("Failed to generate ArgoCD diff comment template: err=%s\n", err)
+				} else if len(templateOutput) > githubCommentMaxSize {
+					ghPrClientDetails.PrLogger.Warnf("Diff comment is too large (%d bytes), using concise template", len(templateOutput))
+					err, templateOutput = executeTemplate(ghPrClientDetails.PrLogger, "argoCdDiffConcise", "argoCD-diff-pr-comment-concise.gotmpl", diffCommentData)
+					if err != nil {
+						prHandleError = err
+						ghPrClientDetails.PrLogger.Errorf("Failed to generate ArgoCD diff comment template: err=%s\n", err)
+					}
 				}
+
 				err = commentPR(ghPrClientDetails, templateOutput)
 				if err != nil {
 					prHandleError = err
-					log.Errorf("Failed to comment ArgoCD diff: err=%s\n", err)
+					ghPrClientDetails.PrLogger.Errorf("Failed to comment ArgoCD diff: err=%s\n", err)
 				}
 			} else {
 				ghPrClientDetails.PrLogger.Debugf("Diff not find affected ArogCD apps")

templates/argoCD-diff-pr-comment-concise.gotmpl

@@ -0,0 +1,47 @@
+{{define "argoCdDiffConcise"}}
+Diff of ArgoCD applications(⚠️ concise view, full diff didn't fit GH comment):
+{{ range $appDiffResult := .DiffOfChangedComponents }}
+
+
+{{if $appDiffResult.DiffError }}
+⚠️ ⚠️ **Error getting diff from ArgoCD** (`{{ $appDiffResult.ComponentPath }}`) ⚠️ ⚠️ 
+``` 
+{{ $appDiffResult.DiffError }}
+
+```
+
+{{- else }}
+<img src="https://argo-cd.readthedocs.io/en/stable/assets/favicon.png" width="20"/> **[{{ $appDiffResult.ArgoCdAppName }}]({{ $appDiffResult.ArgoCdAppURL }})** @ `{{ $appDiffResult.ComponentPath }}`
+{{if $appDiffResult.HasDiff }}
+
+<details><summary>ArgoCD list of changed objects(Click to expand):</summary>
+
+{{ range $objectDiff := $appDiffResult.DiffElements }}
+{{-  if $objectDiff.Diff}}
+`{{ $objectDiff.ObjectNamespace }}/{{ $objectDiff.ObjectKind}}/{{ $objectDiff.ObjectName }}`
+{{- end}}
+{{- end }}
+
+</details>
+{{- else }}
+No diff 🤷
+{{- end}}
+{{if $appDiffResult.AppWasTemporarilyCreated }}
+⚠️ ⚠️ ⚠️
+This PR appears to create this new application, Telefonistka has **temporarly** created an ArgoCD app object for it just to render its manifests.
+It will not be present in ArgoCD UI for more than a few seconds and it can not be synced from the PR branch
+⚠️ ⚠️ ⚠️
+{{- end}}
+
+{{- end }}
+
+{{- end }}
+
+{{- if .HasSyncableComponens }}
+
+- [ ] <!-- telefonistka-argocd-branch-sync --> Set ArgoCD apps Target Revision to `{{ .BranchName }}`  
+
+{{ end}}
+
+
+{{- end }}