Track altbody in change-detection so existing campaigns actually re-sync

Campaign/parseCampaign never fetched altbody, so campaignUnchanged()
compared everything except it -- a campaign synced before v0.1.3
(altbody always null) whose content otherwise hasn't changed would be
judged unchanged forever and never get updated with the new altbody,
even though every subsequent sync now intends to send one.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -54,8 +54,11 @@ attachments:
 ---
 
 Campaign body goes here, in Markdown. It's sent to listmonk with
-content_type "markdown" — listmonk renders the HTML *and* derives the
+content_type "markdown" for the HTML part; listmonk never derives a
-plaintext alternative itself.
+plaintext alternative on its own, so this same source is also sent
+verbatim as `altbody` — recipients on plaintext-only clients see the
+raw Markdown (and personalization still resolves, since the `{{ }}`
+expressions are still there), rather than getting an HTML-only email.
 ```
 
 - **`subject`** — required.
@@ -68,6 +71,18 @@ plaintext alternative itself.
 - **`type`** — defaults to `regular`. `optin` isn't supported and is rejected at sync time.
 - **`scheduled_at` doesn't exist** — deliberately, since listmonk auto-sends a `scheduled` campaign the moment it fires, which would let a plain `git push` cause a real send.
 
+## Personalization
+
+Listmonk renders each recipient's campaign body as a Go template before converting Markdown to HTML, so a subscriber's `attribs` can be referenced directly in `campaign.md`'s body. `eec`'s signup forms set `first_name` (and `last_name`, if given) as attribs on every subscriber who provides one — subscribers who signed up before that (or via the public form when it collected email only) won't have it set.
+
+Verified working syntax, with a fallback for subscribers who don't have `first_name` set:
+
+```
+{{ if .Subscriber.Attribs.first_name }}Hi {{ .Subscriber.Attribs.first_name }},{{ else }}Hi there,{{ end }}
+```
+
+**Don't trust listmonk's `/api/campaigns/:id/preview` endpoint (or its admin-UI "Preview" button) to test this** — it always renders against listmonk's built-in demo subscriber (`demo@listmonk.app`, attribs `{city: Bengaluru}`), ignoring which subscriber you're looking at, so `first_name` will always look unset there even when it's really set on a real subscriber. Use `campaigns test SLUG EMAIL...` (a real test-send to a real subscriber's own address) to verify personalization actually renders — that's how the syntax above was confirmed.
+
 ## Segmentation
 
 `segment_query` is a raw Postgres-style SQL boolean expression — the same mechanism listmonk's own admin UI search box accepts. Since a campaign can only target whole list(s), `sync` materializes the query into a managed list:
@@ -107,8 +122,8 @@ A starting template (listmonk's own stock `default.tpl`, with the required `{{ U
 
 Each domain/client gets its own content repo, isolated by ordinary Gitea repo permissions — a client with push access to their repo has no path to any other domain's listmonk credentials, because those credentials simply don't exist in their repo.
 
-1. Create a new Gitea repo (e.g. `<client>-campaigns`), private.
+1. Generate a new repo from [`campaigns-template`](https://gitea.reground.org/will/campaigns-template) (Gitea's "Generate Repo," not a clone/fork — it starts the new repo with its own clean history), private.
-2. Add: an empty `campaigns/` directory, `email-templates/campaign.html` (copy the stock template from an existing content repo, or listmonk's own `static/email-templates/default.tpl`), and `.gitea/workflows/{sync,send,test,sync-template}.yml` copied from an existing content repo — each does `go install gitea.reground.org/will/eec-campaigns@<pinned-tag>` then runs the corresponding subcommand, with that repo's own secrets.
+2. Follow that generated repo's README checklist: rename the default-template name, restyle `email-templates/campaign.html` if needed, add secrets, confirm the tool version pin, run `Sync default campaign template` once, replace the README with a short domain-specific one.
 3. Add repo secrets: `CAMPAIGNS_LISTMONK_BASE_URL`, `CAMPAIGNS_LISTMONK_API_USER`, `CAMPAIGNS_LISTMONK_API_TOKEN`, and optionally `CAMPAIGNS_PREVIEW_EMAIL` — scoped to that domain's own listmonk instance and API user.
 4. Manually run the `Sync default campaign template` workflow once before the first real send.
 

internal/campaign/send.go

@@ -39,5 +39,5 @@ func Test(lm *listmonk.Client, slug string, emails []string) error {
 	if camp == nil {
 		return fmt.Errorf("no campaign named %q in listmonk — run sync first", slug)
 	}
-	return lm.TestCampaign(camp.ID, emails)
+	return lm.TestCampaign(camp.ID, camp.AsInput(), emails)
 }

internal/campaign/sync.go

@@ -137,7 +137,7 @@ func syncOne(lm *listmonk.Client, slug, dir, path string, defaultPreviewEmails [
 	}
 	var previewErr error
 	if len(recipients) > 0 {
-		previewErr = lm.TestCampaign(campaignID, recipients)
+		previewErr = lm.TestCampaign(campaignID, input, recipients)
 	}
 	return syncOneResult{Changed: true, PreviewErr: previewErr}, nil
 }
@@ -217,6 +217,10 @@ func attachmentFilename(slug, relPath string, content []byte) string {
 func campaignUnchanged(existing *listmonk.Campaign, input listmonk.CampaignInput) bool {
 	return existing.Subject == input.Subject &&
 		existing.Body == input.Body &&
+		// altbody always mirrors body (see CampaignInput.payload) -- comparing
+		// it here is what catches a campaign synced before that started, whose
+		// stored altbody is still null even though its body hasn't changed.
+		existing.AltBody == input.Body &&
 		existing.FromEmail == input.FromEmail &&
 		existing.TemplateID == input.TemplateID &&
 		existing.Type == input.Type &&

internal/campaign/sync_test.go

@@ -31,6 +31,7 @@ type fakeCampaign struct {
 	Status     string
 	Subject    string
 	Body       string
+	AltBody    string
 	FromEmail  string
 	TemplateID int
 	Type       string
@@ -138,7 +139,7 @@ func (c fakeCampaign) toJSON() map[string]any {
 	}
 	return map[string]any{
 		"id": c.ID, "name": c.Name, "status": c.Status, "subject": c.Subject,
-		"body": c.Body, "from_email": c.FromEmail, "template_id": c.TemplateID,
+		"body": c.Body, "altbody": c.AltBody, "from_email": c.FromEmail, "template_id": c.TemplateID,
 		"type": c.Type, "tags": c.Tags, "lists": lists, "media": media,
 	}
 }
@@ -155,7 +156,7 @@ func (f *fakeListmonk) createCampaign(w http.ResponseWriter, r *http.Request) {
 	body := decodeBody(r)
 	c := fakeCampaign{
 		ID: f.id(), Name: str(body["name"]), Status: "draft",
-		Subject: str(body["subject"]), Body: str(body["body"]),
+		Subject: str(body["subject"]), Body: str(body["body"]), AltBody: str(body["altbody"]),
 		FromEmail: str(body["from_email"]), TemplateID: toInt(body["template_id"]),
 		Type: str(body["type"]), Tags: toStrings(body["tags"]),
 		ListIDs: toInts(body["lists"]), MediaIDs: toInts(body["media"]),
@@ -171,6 +172,7 @@ func (f *fakeListmonk) updateCampaign(w http.ResponseWriter, r *http.Request) {
 		if f.campaigns[i].ID == id {
 			f.campaigns[i].Subject = str(body["subject"])
 			f.campaigns[i].Body = str(body["body"])
+			f.campaigns[i].AltBody = str(body["altbody"])
 			f.campaigns[i].FromEmail = str(body["from_email"])
 			f.campaigns[i].TemplateID = toInt(body["template_id"])
 			f.campaigns[i].Type = str(body["type"])

internal/listmonk/listmonk.go

@@ -289,6 +289,7 @@ type Campaign struct {
 	Status     string
 	Subject    string
 	Body       string
+	AltBody    string
 	FromEmail  string
 	TemplateID int
 	Type       string
@@ -297,6 +298,23 @@ type Campaign struct {
 	MediaIDs   []int
 }
 
+// AsInput converts a fetched Campaign back into the CampaignInput shape,
+// for callers (e.g. Test) that need to re-send a campaign's current fields
+// against an endpoint that validates the full campaign body.
+func (camp *Campaign) AsInput() CampaignInput {
+	return CampaignInput{
+		Name:       camp.Name,
+		Subject:    camp.Subject,
+		FromEmail:  camp.FromEmail,
+		TemplateID: camp.TemplateID,
+		Type:       camp.Type,
+		Tags:       camp.Tags,
+		ListIDs:    camp.ListIDs,
+		Body:       camp.Body,
+		MediaIDs:   camp.MediaIDs,
+	}
+}
+
 // CampaignInput is what sync.go builds from a campaign's frontmatter+body to
 // create or update a listmonk campaign.
 type CampaignInput struct {
@@ -318,7 +336,23 @@ func (in CampaignInput) payload() map[string]any {
 		"lists":        in.ListIDs,
 		"content_type": "markdown",
 		"body":         in.Body,
-		"type":         in.Type,
+		// listmonk never derives a plaintext alternative from body/HTML on its
+		// own (models/campaigns.go only compiles AltBodyTpl, and
+		// internal/manager/message.go only emits a text/plain part, when
+		// altbody is explicitly non-null) — confirmed against the deployed
+		// v6.2.0 source. Reusing the same raw Markdown+template source as the
+		// altbody gets it personalized identically to body (AltBodyTpl compiles
+		// whenever the text contains {{ }} expressions), at the cost of
+		// Markdown syntax like *emphasis* showing up literally in plaintext
+		// clients — an acceptable, well-established tradeoff for Markdown.
+		"altbody": in.Body,
+		"type":    in.Type,
+		// listmonk's create/update handlers default an omitted messenger to
+		// "email" before validating, but the test-send handler validates the
+		// raw request body as-is — an omitted messenger there fails with
+		// "Unknown messenger .". eec-campaigns only ever sends email, so set
+		// it explicitly everywhere rather than relying on that asymmetry.
+		"messenger": "email",
 	}
 	if in.FromEmail != "" {
 		p["from_email"] = in.FromEmail
@@ -348,6 +382,7 @@ func parseCampaign(data []byte) (*Campaign, error) {
 		Status     string   `json:"status"`
 		Subject    string   `json:"subject"`
 		Body       string   `json:"body"`
+		AltBody    string   `json:"altbody"`
 		FromEmail  string   `json:"from_email"`
 		TemplateID int      `json:"template_id"`
 		Type       string   `json:"type"`
@@ -376,6 +411,7 @@ func parseCampaign(data []byte) (*Campaign, error) {
 		Status:     parsed.Status,
 		Subject:    parsed.Subject,
 		Body:       parsed.Body,
+		AltBody:    parsed.AltBody,
 		FromEmail:  parsed.FromEmail,
 		TemplateID: parsed.TemplateID,
 		Type:       parsed.Type,
@@ -482,14 +518,18 @@ func (c *Client) SetCampaignStatus(id int, status string) error {
 }
 
 // TestCampaign sends a preview of the campaign's current content to the
-// given addresses without touching its status. Request field confirmed
+// given addresses without touching its status. listmonk's test-send handler
-// against knadh/listmonk's actual handler source (cmd/campaigns.go's
+// binds the request into the same campReq struct create/update use and
-// campReq.SubscriberEmails, json tag "subscribers").
+// validates it in full, so the campaign's other fields (in particular a
-func (c *Client) TestCampaign(id int, emails []string) error {
+// non-empty "name") must be sent alongside "subscribers" — a request with
+// just {"subscribers": [...]} fails listmonk's own validation with "Invalid
+// length for name" before the "subscribers" field is ever looked at.
+func (c *Client) TestCampaign(id int, in CampaignInput, emails []string) error {
 	if len(emails) == 0 {
 		return nil
 	}
-	payload := map[string]any{"subscribers": emails}
+	payload := in.payload()
+	payload["subscribers"] = emails
 	respBody, status, err := c.do(http.MethodPost, fmt.Sprintf("/api/campaigns/%d/test", id), payload)
 	if err != nil {
 		return fmt.Errorf("sending test for campaign %d: %w", id, err)

internal/listmonk/listmonk_test.go

@@ -311,13 +311,17 @@ func TestTestCampaign_SendsSubscribersList(t *testing.T) {
 	defer srv.Close()
 
 	c := New(srv.URL, "u", "t")
-	if err := c.TestCampaign(7, []string{"me@example.com"}); err != nil {
+	in := CampaignInput{Name: "launch", Subject: "Hi", Body: "body", Type: "regular"}
+	if err := c.TestCampaign(7, in, []string{"me@example.com"}); err != nil {
 		t.Fatalf("TestCampaign: %v", err)
 	}
 	subs, ok := gotBody["subscribers"].([]any)
 	if !ok || len(subs) != 1 || subs[0] != "me@example.com" {
 		t.Errorf("expected subscribers=[me@example.com], got %+v", gotBody)
 	}
+	if gotBody["name"] != "launch" {
+		t.Errorf("expected the full campaign body (name=launch) alongside subscribers, got %+v", gotBody)
+	}
 }
 
 func TestErrorResponsesAreWrappedWithStatusAndBody(t *testing.T) {