Custom Event without subject makes emulator crash

[BPHvZ]

Environment info

firebase-tools: 11.30.0

Platform: macOS

Steps to reproduce

• Use firestore-stripe-payments extension
• Setup custom events in the extension using eventarc
• Use Firebase emulator
• Receive an event without subject in attributes
• Emulator will crash
• Log reports error is in getOptionalAttribute in eventarcEmulatorUtils.js

Expected behavior

Emulator should parse the event correctly because subject is optional.

Actual behavior

Emulator crashes because it's unable to parse the event.

Logs

[info] Received custom event at channel projects/tell-the-dj/locations/europe-west4/channels/firebase: {
  "@type": "type.googleapis.com/io.cloudevents.v1.CloudEvent",
  "id": "9e080860-8da2-43fd-a726-f1fe9ff9d2ac",
  "type": "com.stripe.v1.price.updated",
  "specVersion": "1.0",
  "source": "projects/tell-the-dj/instances/firestore-stripe-payments",
  "attributes": {
    "time": {
      "ceTimestamp": "2023-05-05T23:18:23.434Z"
    },
    "datacontenttype": {
      "ceString": "application/json"
    }
  },
  "textData": "{\"id\":\"price_1N4XURBOBLXrmMvIxsRjtdYh\",\"object\":\"price\",\"active\":true,\"billing_scheme\":\"per_unit\",\"created\":1683327159,\"currency\":\"eur\",\"custom_unit_amount\":null,\"livemode\":false,\"lookup_key\":null,\"metadata\":{},\"nickname\":null,\"product\":\"prod_NqDwGZ7f5XsPUY\",\"recurring\":null,\"tax_behavior\":\"unspecified\",\"tiers_mode\":null,\"transform_quantity\":null,\"type\":\"one_time\",\"unit_amount\":102,\"unit_amount_decimal\":\"102\"}"
} {"metadata":{"emulator":{"name":"eventarc"},"message":"Received custom event at channel projects/tell-the-dj/locations/europe-west4/channels/firebase: {\n  \"@type\": \"type.googleapis.com/io.cloudevents.v1.CloudEvent\",\n  \"id\": \"9e080860-8da2-43fd-a726-f1fe9ff9d2ac\",\n  \"type\": \"com.stripe.v1.price.updated\",\n  \"specVersion\": \"1.0\",\n  \"source\": \"projects/tell-the-dj/instances/firestore-stripe-payments\",\n  \"attributes\": {\n    \"time\": {\n      \"ceTimestamp\": \"2023-05-05T23:18:23.434Z\"\n    },\n    \"datacontenttype\": {\n      \"ceString\": \"application/json\"\n    }\n  },\n  \"textData\": \"{\\\"id\\\":\\\"price_1N4XURBOBLXrmMvIxsRjtdYh\\\",\\\"object\\\":\\\"price\\\",\\\"active\\\":true,\\\"billing_scheme\\\":\\\"per_unit\\\",\\\"created\\\":1683327159,\\\"currency\\\":\\\"eur\\\",\\\"custom_unit_amount\\\":null,\\\"livemode\\\":false,\\\"lookup_key\\\":null,\\\"metadata\\\":{},\\\"nickname\\\":null,\\\"product\\\":\\\"prod_NqDwGZ7f5XsPUY\\\",\\\"recurring\\\":null,\\\"tax_behavior\\\":\\\"unspecified\\\",\\\"tiers_mode\\\":null,\\\"transform_quantity\\\":null,\\\"type\\\":\\\"one_time\\\",\\\"unit_amount\\\":102,\\\"unit_amount_decimal\\\":\\\"102\\\"}\"\n}"}}
[debug] [2023-05-05T23:18:23.528Z] TypeError: Cannot read properties of undefined (reading 'ceString')
    at getOptionalAttribute (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/lib/emulator/eventarcEmulatorUtils.js:39:34)
    at cloudEventFromProtoToJson (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/lib/emulator/eventarcEmulatorUtils.js:24:18)
    at /Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:93:88
    at Array.map (<anonymous>)
    at EventarcEmulator.triggerCustomEventFunction (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:89:14)
    at publishEventsHandler (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:56:22)
    at Layer.handle [as handle_request] (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/node_modules/express/lib/router/route.js:144:13)
    at IncomingMessage.<anonymous> (/Users/bart/Desktop/SimpleAppsFarm/tell_the_dj_firebase/functions/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:67:17)
    at IncomingMessage.emit (node:events:525:35)
[error] 
[error] Error: An unexpected error has occurred.

[google-oss-bot]

This issue does not seem to follow the issue template. Make sure you provide all the required information.

[Zambonilli]

Reproduced this with a custom event published via the firebase-admin/eventarc Channel type. When not setting the subject, the emulator crashes with the same TypeError: Cannot read properties of undefined (reading 'ceString') error. After adding the subject, the eventarc emulator does not crash.

[joehan]

@Zambonilli could you share the debug logs & what version of firebase-tools you are using? I believe this issue is fixed, but its possible that there is somewhere else in the code where we are unsafely accessing 'ceString'

[Zambonilli]

I'm using firebase-tools version 11.30.0 and below is the stack trace of the crashing error.

[debug] [2023-06-29T19:31:05.121Z] TypeError: Cannot read properties of undefined (reading 'ceString')
    at getOptionalAttribute (/usr/local/lib/node_modules/firebase-tools/lib/emulator/eventarcEmulatorUtils.js:39:34)
    at cloudEventFromProtoToJson (/usr/local/lib/node_modules/firebase-tools/lib/emulator/eventarcEmulatorUtils.js:24:18)
    at /usr/local/lib/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:93:88
    at Array.map (<anonymous>)
    at EventarcEmulator.triggerCustomEventFunction (/usr/local/lib/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:89:14)
    at publishEventsHandler (/usr/local/lib/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:56:22)
    at Layer.handle [as handle_request] (/usr/local/lib/node_modules/firebase-tools/node_modules/express/lib/router/layer.js:95:5)
    at next (/usr/local/lib/node_modules/firebase-tools/node_modules/express/lib/router/route.js:144:13)
    at IncomingMessage.<anonymous> (/usr/local/lib/node_modules/firebase-tools/lib/emulator/eventarcEmulator.js:67:17)
    at IncomingMessage.emit (node:events:513:28)
[error] 
[error] Error: An unexpected error has occurred.

[joehan]

Ahhh - the fix for this went out in 12.0.1, so you'll need to upgrade to get it.