Cycle previews through the walk

2026-09-17 00:20:00 +02:00
parent 0664b54241
commit 0ba51e06ba
5 changed files with 86 additions and 3 deletions
@@ -877,6 +877,67 @@ void (async () => {
        assert.equal(existsSync(join(dir, `${poster?.hash}.webp`)), true);
    });

+    await test("previews run in cycles during the walk", async () => {
+        const events: string[] = [];
+        const pages: Array<{ messages: CoreMessage[] }> = [
+            {
+                messages: [
+                    message("1000", {
+                        attachments: [attachment({ filename: "a.png", contentType: "image/png" })]
+                    })
+                ]
+            },
+            {
+                messages: [
+                    message("999", {
+                        attachments: [attachment({ filename: "b.png", contentType: "image/png" })]
+                    })
+                ]
+            }
+        ];
+
+        const backend: ScrapeBackend = {
+            name: "puppet",
+            async fetchPage() {
+                events.push("walk");
+                return pages.shift() ?? { messages: [] };
+            }
+        };
+
+        const engine = new ScrapeEngine({
+            rootDir: root,
+            pageSize: 1,
+            pageMinMs: 0,
+            pageMaxMs: 0,
+            sleep: async () => {},
+            random: () => 0,
+            log: () => {},
+            previews: true,
+            walkCyclePages: 1,
+            download: {
+                fetchImpl: async () => {
+                    events.push("preview");
+                    return new Response("webp", { status: 200, headers: { "content-type": "image/webp" } });
+                },
+                minGapMs: 0,
+                maxGapMs: 0,
+                previewMinGapMs: 0,
+                previewMaxGapMs: 0,
+                previewBatchSize: 100,
+                sleep: async () => {}
+            }
+        });
+
+        const started = await engine.start({ channelId: "150", guildId: null, mode: "links", backend });
+        await engine.processQueue();
+
+        assert.equal(engine.get(started.id)?.previewed, 2);
+        const firstPreview = events.indexOf("preview");
+        const secondWalk = events.indexOf("walk", 1);
+        assert.ok(firstPreview !== -1, "a preview happened during the walk");
+        assert.ok(secondWalk > firstPreview, "the walk continued after previews");
+    });
+
    await test("engine resumes a paused scrape from its cursor", async () => {
        const first = new FakeBackend([
            { messages: [message("500"), message("499")] },