fix(js): render GIF terminal artifacts on Node.js

.github/workflows/js.yml

@@ -174,6 +174,11 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
+      - name: Install dependencies (Node)
+        if: matrix.runtime == 'node'
+        working-directory: js
+        run: npm ci
+
       - name: Test Node.js compatibility
         if: matrix.runtime == 'node'
         run: |
@@ -185,6 +190,7 @@ jobs:
               process.exit(1);
             });
           "
+          node --test js/tests/node-terminal-artifacts.mjs
 
   release:
     name: Release JavaScript package

js/.changeset/fuzzy-gifs-wave.md

@@ -0,0 +1,6 @@
+---
+'command-stream': patch
+---
+
+Fix GIF terminal artifact rendering on Node.js by supporting the CommonJS
+default export exposed by `gifenc`.

js/src/terminal-artifacts.mjs

@@ -407,9 +407,12 @@ const renderRecordingSvg = ({ frames, options, font }) => {
 };
 
 const renderGif = async ({ frames, options, font }) => {
-  const [{ Resvg }, { GIFEncoder, applyPalette, quantize }] = await Promise.all(
-    [import('@resvg/resvg-js'), import('gifenc')]
-  );
+  const [{ Resvg }, gifencModule] = await Promise.all([
+    import('@resvg/resvg-js'),
+    import('gifenc'),
+  ]);
+  const gifenc = gifencModule.GIFEncoder ? gifencModule : gifencModule.default;
+  const { GIFEncoder, applyPalette, quantize } = gifenc;
   const { width, height } = dimensions(frames, options);
   const { times } = frameTimes(frames, options.idleTimeLimit);
   const sheet = svgShell({

js/tests/node-terminal-artifacts.mjs

@@ -0,0 +1,33 @@
+import assert from 'node:assert/strict';
+import { mkdtemp, readFile, rm } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { test } from 'node:test';
+
+import { writeTerminalArtifacts } from '../src/terminal-artifacts.mjs';
+
+test('writes GIF terminal artifacts in Node.js', async (context) => {
+  const directory = await mkdtemp(join(tmpdir(), 'command-stream-node-gif-'));
+  context.after(() => rm(directory, { force: true, recursive: true }));
+
+  await writeTerminalArtifacts({
+    directory,
+    frames: [
+      {
+        time: 0,
+        cols: 1,
+        rows: 1,
+        lines: [''],
+        cells: [[]],
+      },
+    ],
+    transcript: '',
+    asciicast: {
+      header: { version: 2, width: 1, height: 1, timestamp: 0, env: {} },
+      events: [],
+    },
+  });
+
+  const gif = await readFile(join(directory, 'recording.gif'));
+  assert.equal(gif.subarray(0, 6).toString(), 'GIF89a');
+});