mostprodev•12mo ago

Deno KV Type Error

When I run await (await kv.get<typeThing>(["example"])).id (the value is an object), it returns a type error because it is a maybe type thing.

7 Replies

mostprodev•12mo ago

The error:

Property 'id' does not exist on type 'KvEntryMaybe<typeThing>'.
  Property 'id' does not exist on type '{ key: KvKey; value: null; versionstamp: null; }'.deno-ts(2339)

Property 'id' does not exist on type 'KvEntryMaybe<typeThing>'.
  Property 'id' does not exist on type '{ key: KvKey; value: null; versionstamp: null; }'.deno-ts(2339)

Perhaps the problem changed. The top is the problem. Although I check that await kv.get<typeThing>(["example"]) != null, with an if statement, it still does not get rid of the error.

NDH•12mo ago

let result = await kv.get<typeThing>(["example"])
// get returns a KvEntryMaybe object = {key, value, versionstamp}
// If (result.value === null) => `key was not found`
if {result.value) console.log(result.value.id);
// no error will be thrown! your error was that 'id' does not exist // on the `KvEntryMaybe` returned by the `get` method.

let result = await kv.get<typeThing>(["example"])
// get returns a KvEntryMaybe object = {key, value, versionstamp}
// If (result.value === null) => `key was not found`
if {result.value) console.log(result.value.id);
// no error will be thrown! your error was that 'id' does not exist // on the `KvEntryMaybe` returned by the `get` method.

mostprodev•12mo ago

Cool. This is not different from != null.

NDH•12mo ago

You could do (result !== null) Be aware that the object returned by the promise KvEntryMaybe = {key, value, versionstamp}, will always return the key, but if not found, both the value, and the timestamp will be null.

mostprodev•12mo ago

Oh, okay. Thanks.

NDH•12mo ago

Also, as someone could insert a row with the value set to null, it might be best to check the versionstamp for null, rather than the value. Be aware that some folks might just use the multipart key as both key and data, and just put null in the value field.

mostprodev•12mo ago

This doesn't work.

'user_data.value' is possibly 'null'.deno-ts(18047)
(property) value: User | null

'user_data.value' is possibly 'null'.deno-ts(18047)
(property) value: User | null

Even when doing the if statement + the result declaration. Nvm.