test: add missing error handling tests for handleExport

- Refactored index.js in dataform-service to export internals for mocking
- Created index.test.js with test cases for expected behaviors, focusing on catching simulated errors in the job queue and various request payload malformations.
- Updated package.json in dataform-service with `node --test` script.

Author: max-ostapenko

infra/dataform-service/src/index.js

@@ -1,7 +1,7 @@
 import functions from '@google-cloud/functions-framework'
 
 import { BigQueryExport } from './bigquery.js'
-import { callRunJob } from './cloud_run.js'
+import * as cloud_run from './cloud_run.js'
 import { getCompilationResults, runWorkflow } from './dataform.js'
 import { StorageUpload } from './storage.js'
 
@@ -101,7 +101,7 @@ async function handleExport (req, res) {
     } else if (destination === 'firestore') {
       console.info('Firestore export')
       const jobName = `projects/${projectId}/locations/${location}/jobs/${jobId}`
-      await callRunJob(jobName, payload)
+      await internals.callRunJob(jobName, payload)
     } else {
       throw new Error('Bad Request: destination unknown')
     }
@@ -191,7 +191,7 @@ async function handleTrigger (req, res) {
 async function executeAction (actionName, actionArgs) {
   if (actionName === 'runDataformRepo') {
     console.info(`Executing action: ${actionName}`)
-    await runDataformRepo(actionArgs)
+    await internals.runDataformRepo(actionArgs)
   }
 }
 
@@ -241,6 +241,13 @@ async function mainHandler (req, res) {
   }
 }
 
+const internals = {
+  callRunJob: cloud_run.callRunJob,
+  runDataformRepo
+}
+
+export { internals, handleExport, mainHandler }
+
 /**
  * Main entry point for the combined Dataform service.
  * Handles both trigger and export operations based on the request path.

infra/dataform-service/src/index.test.js

@@ -0,0 +1,134 @@
+import test, { mock } from 'node:test'
+import assert from 'node:assert'
+import { internals, handleExport } from './index.js'
+
+test('handleExport handles export job error', async () => {
+  const req = {
+    body: {
+      calls: [[{
+        destination: 'firestore',
+        config: {},
+        query: 'SELECT 1'
+      }]]
+    }
+  }
+
+  let statusCode = null
+  let responseData = null
+
+  const res = {
+    status: (code) => {
+      statusCode = code
+      return {
+        json: (data) => {
+          responseData = data
+        }
+      }
+    }
+  }
+
+  const expectedError = new Error('Mocked error')
+  mock.method(internals, 'callRunJob', async () => {
+    throw expectedError
+  })
+
+  await handleExport(req, res)
+
+  assert.strictEqual(statusCode, 400)
+  assert.deepStrictEqual(responseData.replies, [400])
+  assert.strictEqual(responseData.errorMessage, expectedError)
+
+  mock.restoreAll()
+})
+
+test('handleExport handles missing payload error', async () => {
+  const req = {
+    body: {
+      calls: [[null]]
+    }
+  }
+
+  let statusCode = null
+  let responseData = null
+
+  const res = {
+    status: (code) => {
+      statusCode = code
+      return {
+        json: (data) => {
+          responseData = data
+        }
+      }
+    }
+  }
+
+  await handleExport(req, res)
+
+  assert.strictEqual(statusCode, 400)
+  assert.deepStrictEqual(responseData.replies, [400])
+  assert.strictEqual(responseData.errorMessage, 'Bad Request: no payload received, expected JSON object')
+})
+
+test('handleExport handles missing required keys error', async () => {
+  const req = {
+    body: {
+      calls: [[{
+        destination: 'firestore'
+        // missing config and query
+      }]]
+    }
+  }
+
+  let statusCode = null
+  let responseData = null
+
+  const res = {
+    status: (code) => {
+      statusCode = code
+      return {
+        json: (data) => {
+          responseData = data
+        }
+      }
+    }
+  }
+
+  await handleExport(req, res)
+
+  assert.strictEqual(statusCode, 400)
+  assert.deepStrictEqual(responseData.replies, [400])
+  assert.strictEqual(responseData.errorMessage, 'Bad Request: unexpected payload structure, required keys: destination, config, query')
+})
+
+test('handleExport handles unknown destination error', async () => {
+  const req = {
+    body: {
+      calls: [[{
+        destination: 'unknown',
+        config: {},
+        query: 'SELECT 1'
+      }]]
+    }
+  }
+
+  let statusCode = null
+  let responseData = null
+
+  const res = {
+    status: (code) => {
+      statusCode = code
+      return {
+        json: (data) => {
+          responseData = data
+        }
+      }
+    }
+  }
+
+  await handleExport(req, res)
+
+  assert.strictEqual(statusCode, 400)
+  assert.deepStrictEqual(responseData.replies, [400])
+  assert.ok(responseData.errorMessage instanceof Error)
+  assert.strictEqual(responseData.errorMessage.message, 'Bad Request: destination unknown')
+})

infra/dataform-service/src/package.json

@@ -14,7 +14,8 @@
   "scripts": {
     "start": "npx functions-framework --target=dataform-service --signature-type=http --port=${PORT:-8080}",
     "start_dev": "npx functions-framework --target=dataform-service --signature-type=http --port=8080 --debug",
-    "build": "docker build -t dataform-service ."
+    "build": "docker build -t dataform-service .",
+    "test": "node --test"
   },
   "engines": {
     "node": ">=22.0.0"