test: add browser tests for workflow export and export (API)

Add Playwright E2E tests that download exported files and validate
their JSON structure for both export formats.

browser_tests/fixtures/components/Topbar.ts

@@ -77,9 +77,13 @@ export class Topbar {
     return this._saveWorkflow(workflowName, 'Export')
   }
 
+  exportWorkflowApi(workflowName: string): Promise<void> {
+    return this._saveWorkflow(workflowName, 'Export (API)')
+  }
+
   async _saveWorkflow(
     workflowName: string,
-    command: 'Save' | 'Save As' | 'Export'
+    command: 'Save' | 'Save As' | 'Export' | 'Export (API)'
   ) {
     await this.triggerTopbarCommand(['File', command])
     await this.getSaveDialog().fill(workflowName)

browser_tests/tests/exportWorkflow.spec.ts

@@ -0,0 +1,130 @@
+import { readFileSync } from 'fs'
+
+import { expect } from '@playwright/test'
+
+import type {
+  ComfyApiWorkflow,
+  ComfyWorkflowJSON
+} from '../../src/platform/workflow/validation/schemas/workflowSchema'
+import { comfyPageFixture as test } from '../fixtures/ComfyPage'
+
+const EXPECTED_NODE_TYPES = [
+  'CheckpointLoaderSimple',
+  'CLIPTextEncode',
+  'CLIPTextEncode',
+  'EmptyLatentImage',
+  'KSampler',
+  'SaveImage',
+  'VAEDecode'
+]
+
+test.describe('Export workflow', () => {
+  test('Export downloads workflow JSON with correct structure', async ({
+    comfyPage
+  }) => {
+    await comfyPage.workflow.loadWorkflow('default')
+
+    const downloadPromise = comfyPage.page.waitForEvent('download')
+    await comfyPage.menu.topbar.exportWorkflow('test_export.json')
+    const download = await downloadPromise
+
+    expect(download.suggestedFilename()).toBe('test_export.json')
+
+    const filePath = await download.path()
+    expect(filePath).toBeTruthy()
+    const parsed: ComfyWorkflowJSON = JSON.parse(
+      readFileSync(filePath!, 'utf-8')
+    )
+
+    expect(parsed.version).toBe(0.4)
+    expect(parsed.nodes).toHaveLength(7)
+    expect(parsed.links).toHaveLength(9)
+    expect(parsed.extra).toBeDefined()
+
+    const nodeTypes = parsed.nodes.map((n) => n.type).sort()
+    expect(nodeTypes).toEqual([...EXPECTED_NODE_TYPES].sort())
+
+    for (const node of parsed.nodes) {
+      expect(node.id).toBeGreaterThan(0)
+      expect(node.type).toBeTruthy()
+      expect(node.pos).toBeDefined()
+
+      for (const slot of node.inputs ?? []) {
+        expect(slot).not.toHaveProperty('localized_name')
+        expect(slot).not.toHaveProperty('label')
+      }
+      for (const slot of node.outputs ?? []) {
+        expect(slot).not.toHaveProperty('localized_name')
+        expect(slot).not.toHaveProperty('label')
+      }
+    }
+  })
+
+  test('Export (API) downloads API JSON with correct structure', async ({
+    comfyPage
+  }) => {
+    await comfyPage.workflow.loadWorkflow('default')
+
+    const downloadPromise = comfyPage.page.waitForEvent('download')
+    await comfyPage.menu.topbar.exportWorkflowApi('test_api_export.json')
+    const download = await downloadPromise
+
+    expect(download.suggestedFilename()).toBe('test_api_export.json')
+
+    const filePath = await download.path()
+    expect(filePath).toBeTruthy()
+    const parsed: ComfyApiWorkflow = JSON.parse(
+      readFileSync(filePath!, 'utf-8')
+    )
+
+    // Node ID keys must be numeric or colon-separated numeric paths
+    // e.g. "3", "48:9", "65:35:76"
+    const nodeIdPattern = /^\d+(?::\d+)*$/
+    const keys = Object.keys(parsed)
+    expect(keys).toHaveLength(7)
+    for (const key of keys) {
+      expect(key).toMatch(nodeIdPattern)
+    }
+
+    const entries = Object.values(parsed)
+    const classTypes = entries.map((e) => e.class_type).sort()
+    expect(classTypes).toEqual([...EXPECTED_NODE_TYPES].sort())
+
+    // Each entry must have exactly 3 keys with correct types
+    for (const entry of entries) {
+      expect(Object.keys(entry).sort()).toEqual(
+        ['_meta', 'class_type', 'inputs'].sort()
+      )
+      expect(typeof entry.class_type).toBe('string')
+      expect(entry.class_type.length).toBeGreaterThan(0)
+      expect(typeof entry.inputs).toBe('object')
+      expect(entry.inputs).not.toBeNull()
+      expect(entry._meta).toEqual({ title: expect.any(String) })
+    }
+
+    // No visual/UI properties should leak into the API format
+    for (const entry of entries) {
+      for (const uiProp of ['pos', 'size', 'flags', 'order', 'mode']) {
+        expect(entry).not.toHaveProperty(uiProp)
+      }
+    }
+
+    // Verify connection tuples: [stringNodeId, numberSlotIndex]
+    const ksampler = entries.find((e) => e.class_type === 'KSampler')
+    expect(ksampler).toBeDefined()
+    for (const inputName of ['model', 'positive', 'negative', 'latent_image']) {
+      const value = ksampler!.inputs[inputName]
+      expect(Array.isArray(value)).toBe(true)
+      expect(value).toHaveLength(2)
+      expect(value[0]).toMatch(nodeIdPattern)
+      expect(typeof value[1]).toBe('number')
+    }
+
+    // Verify widget values are plain scalars, not connection tuples
+    expect(typeof ksampler!.inputs['steps']).toBe('number')
+    expect(typeof ksampler!.inputs['cfg']).toBe('number')
+    expect(typeof ksampler!.inputs['sampler_name']).toBe('string')
+    expect(typeof ksampler!.inputs['scheduler']).toBe('string')
+    expect(typeof ksampler!.inputs['denoise']).toBe('number')
+  })
+})