No hydration for maps stored in arrays

[kevgug]

Failing tests

• array_of_maps
• map_size_in_array (getting any property, not just size, would also fail)

How to reproduce

runtime/tests/array_of_maps.js

const baseArray = [
    new Map([["a", 1], ["b", 2]]),
    new Map([["a", "3"], ["b", "4"]]),
    new Map([["a", 5]]),
];

function checkMapValueEquivalence({ map1, map2, test_ctx }) {
    console.log("map1", map1);
    console.log("map2", map2);
    if (map1.size !== map2.size) {
        throw new Error(
            `${test_ctx} different number of keys (${map1.size} !== ${map2.size})`,
        );
    }
    for (const [key, value] of map1) {
        console.log("key of map1", key);
        console.log("value of map1", value);
        if (!map2.has(key)) {
            throw new Error(`${test_ctx} key ${key} not found in map2 keys`);
        }
        if (map2.get(key) !== value) {
            console.log("map2.get(key)", map2.get(key));
            throw new Error(
                `${test_ctx} different values for key ${key} (${value} !== ${
                    map2.get(key)
                })`,
            );
        }
    }
}

{
    const object = {
        value: [...baseArray],
    };

    setRoot("test-root", object);
    commit();
}

{
    const root = getRoot("test-root");
    if (!root) {
        throw new Error("root should exist");
    }
    if (!root.value) {
        throw new Error("root.value should exist");
    }
    if (root.value.length !== baseArray.length) {
        throw new Error(`root.value should have length ${baseArray.length}`);
    }
    for (let i = 0; i < root.value.length; i++) {
        checkMapValueEquivalence({
            map1: root.value[i],
            map2: baseArray[i],
            test_ctx: "first getRoot after commit",
        });
    }
}

Run the test

In runtime/src/tests.rs run the single test js_test!(array_of_maps);

Terminal output

map1 CloudstateMapReference {
  objectId: "9cbe9dc6-64c9-4b17-a7c1-7df6f5f24b27"
}
map2 Map(2) { "a" => 1, "b" => 2 }

Expected output

map1 Map(2) { "a" => 1, "b" => 2 }
map2 Map(2) { "a" => 1, "b" => 2 }

What I think the issue is

In runtime/src/extensions/cloudstate.js, the hydrate method is called to correctly hydrate the CloudstateArrayReference (which contains a single CloudstateMapReference). But in

Object.defineProperty(object, key, {
    value: this.getArray(value.objectId),
});

the method getArray() doesn't recursively hydrate its elements.

[kevgug]

Failing tests

Test	Status	Notes
Array of maps	❌ Tested
Map size in array	✅ Tested

[subhamengine]

hey, I would like to work on it.