refactor(cli): decompose render phases

packages/cli/src/commands/batchRender.test.ts

@@ -47,11 +47,6 @@ function expectBatchError(fn: () => unknown, title: string): BatchRenderInputErr
   throw new Error("Expected BatchRenderInputError");
 }
 
-function eventType(value: unknown): string | undefined {
-  if (value === null || typeof value !== "object" || Array.isArray(value)) return undefined;
-  return "type" in value && typeof value.type === "string" ? value.type : undefined;
-}
-
 describe("parseBatchRows", () => {
   it("parses a JSON array of variable rows", () => {
     expect(parseBatchRows('[{"name":"Alice"},{"name":"Bob"}]', "rows.json")).toEqual([
@@ -192,7 +187,7 @@ describe("runBatchRender", () => {
     expect(readFileSync(prepared.manifestPath, "utf8")).toContain('"status": "completed"');
   });
 
-  it("emits JSON progress events when json mode is enabled", async () => {
+  it("emits exactly one final JSON document when json mode is enabled", async () => {
     const prepared = prepareBatchRender({
       batchPath: writeJson("rows.json", '[{"name":"Alice"}]'),
       outputTemplate: join(tmpDir, "renders/{name}.mp4"),
@@ -212,12 +207,14 @@ describe("runBatchRender", () => {
       renderOne: async () => ({ renderTimeMs: 10 }),
     });
 
-    const events = log.mock.calls.map((call): unknown => JSON.parse(String(call[0])));
-    expect(events.map(eventType)).toEqual([
-      "batch-row-start",
-      "batch-row-complete",
-      "batch-complete",
-    ]);
+    expect(log).toHaveBeenCalledTimes(1);
+    const result = JSON.parse(String(log.mock.calls[0]?.[0])) as {
+      type: string;
+      completed: number;
+      rows: Array<{ status: string }>;
+    };
+    expect(result).toMatchObject({ type: "batch-complete", completed: 1 });
+    expect(result.rows).toEqual([expect.objectContaining({ status: "completed" })]);
   });
 
   it("continues after row failure by default", async () => {

packages/cli/src/commands/batchRender.ts

@@ -305,10 +305,6 @@ function writeManifest(manifest: BatchManifest): void {
   writeFileSync(manifest.manifestPath, JSON.stringify(manifest, null, 2) + "\n", "utf8");
 }
 
-function emitJsonEvent(event: Record<string, unknown>, json: boolean): void {
-  if (json) console.log(JSON.stringify(event));
-}
-
 async function renderBatchRow(
   row: PreparedBatchRow,
   manifest: BatchManifest,
@@ -322,11 +318,6 @@ async function renderBatchRow(
   manifestRow.status = "running";
   manifestRow.startedAt = new Date().toISOString();
   writeManifest(manifest);
-  emitJsonEvent(
-    { type: "batch-row-start", index: row.index, outputPath: row.outputPath },
-    options.json,
-  );
-
   if (!options.quiet && !options.json) {
     console.log(c.dim(`Batch row ${row.index}: ${row.outputPath}`));
   }
@@ -339,31 +330,12 @@ async function renderBatchRow(
     manifestRow.renderTimeMs = result.renderTimeMs;
     manifestRow.completedAt = new Date().toISOString();
     writeManifest(manifest);
-    emitJsonEvent(
-      {
-        type: "batch-row-complete",
-        index: row.index,
-        outputPath: row.outputPath,
-        durationMs: manifestRow.durationMs,
-        renderTimeMs: manifestRow.renderTimeMs,
-      },
-      options.json,
-    );
     return true;
   } catch (error: unknown) {
     manifestRow.status = "failed";
     manifestRow.error = errorMessage(error);
     manifestRow.completedAt = new Date().toISOString();
     writeManifest(manifest);
-    emitJsonEvent(
-      {
-        type: "batch-row-error",
-        index: row.index,
-        outputPath: row.outputPath,
-        error: manifestRow.error,
-      },
-      options.json,
-    );
     if (!options.quiet && !options.json) {
       console.log(c.error(`  Row ${row.index} failed: ${manifestRow.error}`));
     }
@@ -423,17 +395,19 @@ export async function runBatchRender(options: RunBatchRenderOptions): Promise<Ba
 
   if (stopLaunching) markUnstartedRowsSkipped(manifest);
   writeManifest(manifest);
-  emitJsonEvent(
-    {
-      type: "batch-complete",
-      manifestPath: manifest.manifestPath,
-      total: manifest.total,
-      completed: manifest.completed,
-      failed: manifest.failed,
-      skipped: manifest.skipped,
-    },
-    options.json,
-  );
+  if (options.json) {
+    console.log(
+      JSON.stringify({
+        type: "batch-complete",
+        manifestPath: manifest.manifestPath,
+        total: manifest.total,
+        completed: manifest.completed,
+        failed: manifest.failed,
+        skipped: manifest.skipped,
+        rows: manifest.rows,
+      }),
+    );
+  }
 
   if (!options.quiet && !options.json) {
     console.log("");