EIP-712 signing fails on eth_signTypedData setup

[onkaraman]

Hi all,

the following code works with MetaMask, but on Trust Wallet I have issues:

let signature = await window.ethereum.request({
	method: 'eth_signTypedData_v4',
	params: [connectedAddress,
		JSON.stringify(EIP712types.newRecord(this.state.createName, this.state.createSNr))
	]
});

The value of JSON.stringify(EIP712types.newRecord(this.state.createName, this.state.createSNr)) is

{
	"types": {
		"EIP712Domain": [{
			"name": "name",
			"type": "string"
		}, {
			"name": "version",
			"type": "string"
		}, {
			"name": "chainId",
			"type": "uint256"
		}, {
			"name": "verifyingContract",
			"type": "address"
		}],
		"NewRecord": [{
			"name": "productName",
			"type": "string"
		}, {
			"name": "productUID",
			"type": "string"
		}]
	},
	"primaryType": "NewRecord",
	"domain": {
		"name": "MyDomain",
		"version": "1",
		"chainId": 1337,
		"verifyingContract": "..."
	},
	"message": {
		"productName": "MGS1PS1",
		"productUID": "MGS1PS1"
	}
}

Trust Wallet returns the error:

SyntaxError: Unexpected non-whitespace character after JSON at position 1
    at JSON.parse (<anonymous>)
    at g.value (inpage.js:2:42406)
    at inpage.js:2:40108

I'm testing my dApp locally with ganache.