feat: pass image paths to cover generator in publish route

Made-with: Cursor

src/routes/publish.py

@@ -4,7 +4,7 @@ from calendar import monthrange
 from flask import Blueprint, render_template, request, redirect, url_for, flash, jsonify
 
 from app import db
-from src.models import Article, Issue
+from src.models import Article, Issue, Image
 from src.cover import generate_cover
 from src.epub_builder import build_epub
 import config
@@ -168,14 +168,17 @@ def create_issue():
         a.title for a in articles_for_issue
         if "Obituaries" not in json.loads(a.categories)
     ]
-    categories_list = []
+
+    image_paths = []
     for a in articles_for_issue:
-        categories_list.extend(json.loads(a.categories))
+        first_image = Image.query.filter_by(article_id=a.id).first()
+        if first_image:
+            image_paths.append(first_image.local_path)
 
     try:
         cover_path = generate_cover(
             cover_method, config.ISSUES_DIR, week_start, week_end,
-            headlines, categories_list
+            headlines, image_paths
         )
         epub_path = build_epub(
             week_start, week_end, included_ids, cover_path,

tests/test_publish.py

@@ -0,0 +1,88 @@
+import json
+import os
+from datetime import datetime
+from unittest.mock import MagicMock, patch
+
+from PIL import Image as PILImage
+from werkzeug.datastructures import MultiDict
+
+from src.models import Article, Image
+
+
+def test_publish_route_passes_ordered_image_paths_to_generate_cover(app, client, db, tmp_path):
+    """First image per article, in pub_date order (not form order), passed to generate_cover."""
+    os.makedirs(tmp_path, exist_ok=True)
+    img1 = str(tmp_path / "a1.jpg")
+    img2 = str(tmp_path / "a2.jpg")
+    for p in (img1, img2):
+        PILImage.new("RGB", (100, 100), color="blue").save(p, format="JPEG")
+
+    with app.app_context():
+        a1 = Article(
+            guid="g1",
+            title="Earlier Article",
+            author="A",
+            pub_date=datetime(2026, 4, 6, 10, 0),
+            categories=json.dumps(["Government"]),
+            link="http://example.com/1",
+            content_html="<p>x</p>",
+        )
+        a2 = Article(
+            guid="g2",
+            title="Later Article",
+            author="B",
+            pub_date=datetime(2026, 4, 7, 10, 0),
+            categories=json.dumps(["Culture"]),
+            link="http://example.com/2",
+            content_html="<p>y</p>",
+        )
+        db.session.add_all([a1, a2])
+        db.session.flush()
+        db.session.add_all(
+            [
+                Image(
+                    article_id=a1.id,
+                    original_url="https://example.com/1.jpg",
+                    local_path=img1,
+                    width=100,
+                    height=100,
+                ),
+                Image(
+                    article_id=a2.id,
+                    original_url="https://example.com/2.jpg",
+                    local_path=img2,
+                    width=100,
+                    height=100,
+                ),
+            ]
+        )
+        db.session.commit()
+        id1, id2 = a1.id, a2.id
+
+    mock_cover = MagicMock(return_value="/fake/cover.jpg")
+    mock_epub = MagicMock(return_value="/fake/issue.epub")
+
+    with patch("src.routes.publish.generate_cover", mock_cover), patch(
+        "src.routes.publish.build_epub", mock_epub
+    ):
+        resp = client.post(
+            "/publish",
+            data=MultiDict(
+                [
+                    ("week_start", "2026-04-06"),
+                    ("week_end", "2026-04-12"),
+                    ("cover_method", "mosaic"),
+                    ("article_ids", str(id2)),
+                    ("article_ids", str(id1)),
+                ]
+            ),
+        )
+
+    assert resp.status_code in (302, 303)
+    mock_cover.assert_called_once()
+    args = mock_cover.call_args[0]
+    assert args[0] == "mosaic"
+    assert args[4] == ["Earlier Article", "Later Article"]
+    assert args[5] == [img1, img2]
+
+    mock_epub.assert_called_once()