wasm2js: function table undefined after calling async function

A wasm2js-transpiled JS module is throwing an error after an async call, but the WASM binary is working just fine. The wasm binary is compiled from a rust crate using wasm-bindgen and then built with wasm-pack. For some context, this async call is to a Rust function that then makes a async call back into JS before returning.

The error in particular is

# Unhandled error between tests
-------------------------------
152 |         try {
153 |             return f(a, state.b, ...args);
154 |         } finally {
155 |             if (--state.cnt === 0) {
156 |                 console.debug("In makeMutClosure", {export3: wasm$1.__wbindgen_export_3, wasm1: wasm$1});
157 |                 wasm$1.__wbindgen_export_3.get(state.dtor)(a, state.b);
                             ^
TypeError: undefined is not an object (evaluating 'wasm$1.__wbindgen_export_3.get')
      at real (/Users/joe/git/algorandfoundation/algokit-core/packages/typescript/algokit_utils/dist/algokit_utils.wasm2js.mjs:157:24)

To be clear, the code after the async function still runs, so this seems to be happening async somewhere. Adding a debug statement to this finally block I can see, export 3, which is the function table, is indeed undefined.

In makeMutClosure {
  export3: undefined,
  wasm1: [Object: null prototype] {
    __wbg_composer_free: [Function: $174],
    __wbindgen_add_to_stack_pointer: [Function: $413],
    __wbindgen_export_0: [Function: $330],
    __wbindgen_export_1: [Function: $341],
    __wbindgen_export_2: [Function: $390],
    __wbindgen_export_4: [Function: $375],
    __wbindgen_export_5: [Function: $358],
    __wbindgen_export_6: [Function: $354],
    addressFromPubKey: [Function: $248],
    addressFromString: [Function: $249],
    assignFee: [Function: $99],
    attachSignature: [Function: $192],
    composer_addTransaction: [Function: $138],
    composer_encode: [Function: $131],
    composer_getSuggestedParams: [Function: $336],
    composer_new: [Function: $261],
    composer_toJSON: [Function: $215],
    composer_toString: [Function: $216],
    composer_transactions: [Function: $77],
    composer_valueOf: [Function: $214],
    decodeTransaction: [Function: $86],
    encodeTransaction: [Function: $164],
    encodeTransactionRaw: [Function: $165],
    estimateTransactionSize: [Function: $199],
    getAlgorandConstant: [Function: legalstub$260],
    getEncodedTransactionType: [Function: $61],
    getTransactionId: [Function: $163],
    getTransactionIdRaw: [Function: $162],
    memory: {
      grow: [Function: __wasm_memory_grow],
      buffer: [Getter],
    },
  },
}

The same debug statement when using the WASM binary:

In makeMutClosure {
  export3: Table {
    length: 225,
    grow: [Function: grow],
    get: [Function: get],
    set: [Function: set],
    type: [Function: type],
  },
  wasm: [Object: null prototype] {
    memory: Memory {
      grow: [Function: grow],
      buffer: ArrayBuffer(1179648) [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ... 1179135 more ],
      type: [Function: type],
    },
    composer_addTransaction: [Function: 198],
    composer_encode: [Function: 191],
    composer_getSuggestedParams: [Function: 396],
    composer_transactions: [Function: 137],
    __wbg_composer_free: [Function: 234],
    composer_new: [Function: 321],
    composer_valueOf: [Function: 274],
    composer_toJSON: [Function: 275],
    composer_toString: [Function: 276],
    getEncodedTransactionType: [Function: 121],
    encodeTransaction: [Function: 224],
    encodeTransactionRaw: [Function: 225],
    decodeTransaction: [Function: 146],
    attachSignature: [Function: 252],
    estimateTransactionSize: [Function: 259],
    addressFromPubKey: [Function: 308],
    addressFromString: [Function: 309],
    getTransactionIdRaw: [Function: 222],
    getTransactionId: [Function: 223],
    getAlgorandConstant: [Function: 320],
    assignFee: [Function: 159],
    __wbindgen_export_0: [Function: 390],
    __wbindgen_export_1: [Function: 401],
    __wbindgen_export_2: [Function: 450],
    __wbindgen_export_3: Table {
      length: 225,
      grow: [Function: grow],
      get: [Function: get],
      set: [Function: set],
      type: [Function: type],
    },
    __wbindgen_add_to_stack_pointer: [Function: 473],
    __wbindgen_export_4: [Function: 435],
    __wbindgen_export_5: [Function: 418],
    __wbindgen_export_6: [Function: 414],
  },
}

The JS files: https://gist.github.com/joe-p/0b12f34e45f5152043f3948d34572e40
The repo: https://github.com/algorandfoundation/algokit-core/tree/2b2eba2c60b0a6d008a4a15bbfa3a76374b04441/packages/typescript/algokit_utils

Start with the wasm2js-generated JavaScript files in the linked gist and the referenced algokit-core revision, then reproduce the async Rust-to-JavaScript callback path with wasm-pack output. Compare the failing wasm2js module with the working WASM module around makeMutClosure and __wbindgen_export_3. Done means the async path no longer reaches an undefined function table.