Invalid IDL Message

[infu]

agent-js/packages/candid/src/idl.ts

Line 1337 in 2fe3dd9

throw new Error(`Invalid ${t.display()} argument: ${toReadableString(x)}`);

Is your feature request related to a problem? Please describe.
The error thrown from the above code is not very developer friendly. It's hard to read and figure where the problem is exactly. When you have a record with 10-15 fields, one can waste an hour, trying to figure it out. Not to mention the (Opt) = [ ], which a developer has to figure after searching the documentation and forums.

Describe the solution you'd like
Show exactly which field is causing the problem

Most peculiar things are mentioned in the docs, but I personally missed to see them. https://sdk.dfinity.org/docs/candid-guide/candid-types.html#type-variant

[krpeacock]

@infu do you think this request would be covered under #470?

[infu]

@krpeacock #470 is about receiving and decoding, while this is about encoding and sending.
This is example error message. Try to figure where the problem is from that error, before checking the solution.

Unhandled Rejection (Error): Invalid record {to:variant {principal:principal; address:text}; metadata:record {ttl:opt nat32; use:opt variant {consumable:record {desc:text; useId:text}; cooldown:record {duration:nat32; desc:text; useId:text}}; thumb:variant {internal:record {contentType:text; size:nat32}; external:record {idx:opt nat32; contentType:text}}; content:opt variant {internal:record {contentType:text; size:nat32}; external:record {idx:opt nat32; contentType:text}}; extensionCanister:opt principal; quality:nat8; hold:opt variant {external:record {desc:text; holdId:text}}; lore:opt text; name:opt text; secret:bool; attributes:vec record {text; int16}; transfer:variant {unrestricted; bindsForever; bindsDuration:nat32}}} argument: {"to":{"address":"504d8fbe45d3dc4ef0cf7f3bcfb0a5a5a80cb0f08e603a02a6f5282fe48e6adb"},"metadata":{"name":["werwer"],"lore":[],"use":[{"cooldown":{"desc":"qweq weqweqweqwe","duration":30,"useId":"qweqweq weqweqwe"}}],"transfer":{"bindsDuration":"1440"},"hold":[],"quality":1,"ttl":[],"attributes":[],"content":[],"thumb":{"internal":{"url":"blob:http://localhost:3000/aa3683bb-1bba-42a2-a7e5-df0dec08abf2","contentType":"image/jpeg","size":8569}},"secret":false,"extensionCanister":[]}}

The error is in bindsDuration, should be nat not string.

[infu]

fixed #633