skipLibCheck in tsconfig should not be a build requirement

[mountainpath9]

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Viem Version

2.17.9

Current Behavior

Errors when compiling the npm packaged library:

node_modules/viem/_types/clients/decorators/public.d.ts:1015:426 - error TS2344: Type 'request' does not satisfy the constraint 'PrepareTransactionRequestRequest<Chain, chainOverride, DeriveChain<Chain, chainOverride>>'.
  Type 'PrepareTransactionRequestRequest<chain, chainOverride>' is not assignable to type 'PrepareTransactionRequestRequest<Chain, chainOverride, DeriveChain<Chain, chainOverride>>'.
    Type 'PrepareTransactionRequestRequest<chain, chainOverride>' is not assignable to type 'UnionOmit<ExtractChainFormatterParameters<DeriveChain<Chain, chainOverride>, "transactionRequest", TransactionRequest>, "from">'.
      Type 'request' is not assignable to type 'UnionOmit<ExtractChainFormatterParameters<DeriveChain<Chain, chainOverride>, "transactionRequest", TransactionRequest>, "from">'.
        Type 'PrepareTransactionRequestRequest<chain, chainOverride>' is not assignable to type 'UnionOmit<ExtractChainFormatterParameters<DeriveChain<Chain, chainOverride>, "transactionRequest", TransactionRequest>, "from">'.

1015     prepareTransactionRequest: <const request extends PrepareTransactionRequestRequest<chain, chainOverride>, chainOverride extends Chain | undefined = undefined, accountOverride extends Account | Address | undefined = undefined>(args: PrepareTransactionRequestParameters<chain, account, chainOverride, accountOverride, request>) => Promise<PrepareTransactionRequestReturnType<Chain, account, chainOverride, accountOverride, request>>;
                                                                                                                                                                                                                                                                                                                                                                                                                                              ~~~~~~~

node_modules/viem/_types/clients/decorators/wallet.d.ts:164:426 - error TS2344: Type 'request' does not satisfy the constraint 'PrepareTransactionRequestRequest<Chain, chainOverride, DeriveChain<Chain, chainOverride>>'.
  Type 'PrepareTransactionRequestRequest<chain, chainOverride>' is not assignable to type 'PrepareTransactionRequestRequest<Chain, chainOverride, DeriveChain<Chain, chainOverride>>'.
    Type 'PrepareTransactionRequestRequest<chain, chainOverride>' is not assignable to type 'UnionOmit<ExtractChainFormatterParameters<DeriveChain<Chain, chainOverride>, "transactionRequest", TransactionRequest>, "from">'.
      Type 'request' is not assignable to type 'UnionOmit<ExtractChainFormatterParameters<DeriveChain<Chain, chainOverride>, "transactionRequest", TransactionRequest>, "from">'.
        Type 'PrepareTransactionRequestRequest<chain, chainOverride>' is not assignable to type 'UnionOmit<ExtractChainFormatterParameters<DeriveChain<Chain, chainOverride>, "transactionRequest", TransactionRequest>, "from">'.

164     prepareTransactionRequest: <const request extends PrepareTransactionRequestRequest<chain, chainOverride>, chainOverride extends Chain | undefined = undefined, accountOverride extends Account | Address | undefined = undefined>(args: PrepareTransactionRequestParameters<chain, account, chainOverride, accountOverride, request>) => Promise<PrepareTransactionRequestReturnType<Chain, account, chainOverride, accountOverride, request>>;
                                                                                                                                                                                                                                                                                                                                                                                                                                             ~~~~~~~

node_modules/viem/_types/types/utils.d.ts:184:67 - error TS2536: Type '_K' cannot be used to index type 'fallback'.

184     [_K in Exclude<keys, keyof Item>]?: fallback extends object ? fallback[_K] : undefined;
                                                                      ~~~~~~~~~~~~


Found 3 errors in 3 files.

Errors  Files
     1  node_modules/viem/_types/clients/decorators/public.d.ts:1015
     1  node_modules/viem/_types/clients/decorators/wallet.d.ts:164
     1  node_modules/viem/_types/types/utils.d.ts:184

Expected Behavior

A clean compilation without errors

Steps To Reproduce

Run tsc in the linked minimal reproduceable example:

git clone [email protected]:mountainpath9/viem-test.git
cd viem-test
yarn
yarn tsc --noEmit

Link to Minimal Reproducible Example

https://github.com/mountainpath9/viem-test

Anything else?

Disabling error checking of the library by setting "skipLibCheck": true in tsconfig.json works around the problem.

[mountainpath9]

Unclear why this was converted from an issue to a discussion. There's several open discussion topics on this already, which have suggested the workaround of enabling skipLibCheck.

Shouldn't the published library type check without errors? Or, should the docs be updated to indicate that skipLibCheck should be enabled?

[jxom]

It is recommended for skipLibCheck to be truthy for TypeScript projects in general. I don’t see an advantage to type checking libs as the libs should already type check themself. It can be disabled, but then it would require further modifications to the consumers TS Config to work.

[mountainpath9]

I prefer to have skipLibCheck false to ensure that the types in my dependencies make sense for the version of typescript I am using.

If I wish to have skipLibCheck false for a viem based, what do I need to do? Can you suggest what needs to change in the minimal example linked to achieve clean compilation?

[tmm]

Should be fixed by 37d837c

Highly recommend turning on 'skipLibCheck' (unless you have loads of .d.ts files in your source) as without it TypeScript is probably running much slower for very little gain.