same-schema-detect.js

const root = {
    val: 1,
    left: {
        val: 2,
        left: null,
        right: null
    },
    right: {
        val: 3,
        left: null,
        right: null
    }
};

const schemalize = obj => {
    const schema = [];
    for (let key in obj) {
        schema.push({
            name: key,
            type: typeof obj[key]
        });
    }
    return schema;
};

const compareSchema = (a, b) => {
    if (a.length != b.length) return false;
    for (let i = 0; i < a.length; i++) {
        if (a[i].name !== b[i].name || a[i].type !== b[i].type) {
            return false;
        }
    }
    return true;
};

const isSameSchema = schemas => !schemas.some(s => !compareSchema(schemas[0], s));

const rootSchema = schemalize(root);
const leftSchema = schemalize(root.left);
const rightSchema = schemalize(root.right);

const result = isSameSchema([rootSchema, leftSchema, rightSchema]);
debug(result);

debug(rootSchema);