Learn Next.js Chapter 6. Vercel deployment fails with linting errors

[anegoiu]

Summary

When I try to deploy the app I am seeing linting issues in app/lib/data.ts.

I noticed this disscussion on the same chapter but my issues seems different.

[21:56:09.801] Running build in Washington, D.C., USA (East) – iad1
[21:56:09.915] Cloning github.com/anegoiu/vercel-tutorial (Branch: master, Commit: 2f3ff74)
[21:56:10.242] Previous build cache not available
[21:56:10.370] Cloning completed: 455.248ms
[21:56:10.704] Running "vercel build"
[21:56:11.120] Vercel CLI 39.2.0
[21:56:11.476] Detected `pnpm-lock.yaml` version 9 generated by pnpm@9.x
[21:56:11.486] Installing dependencies...
[21:56:12.142] Lockfile is up to date, resolution step is skipped
[21:56:12.176] Progress: resolved 1, reused 0, downloaded 0, added 0
[21:56:12.226] Packages: +228
[21:56:12.226] ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
[21:56:13.177] Progress: resolved 228, reused 0, downloaded 140, added 129
[21:56:14.213] Progress: resolved 228, reused 0, downloaded 197, added 187
[21:56:15.215] Progress: resolved 228, reused 0, downloaded 210, added 199
[21:56:16.215] Progress: resolved 228, reused 0, downloaded 225, added 215
[21:56:17.217] Progress: resolved 228, reused 0, downloaded 228, added 226
[21:56:18.218] Progress: resolved 228, reused 0, downloaded 228, added 227
[21:56:18.587] Progress: resolved 228, reused 0, downloaded 228, added 228, done
[21:56:18.693] .../node_modules/utf-8-validate install$ node-gyp-build
[21:56:18.694] .../node_modules/bufferutil install$ node-gyp-build
[21:56:18.694] .../bcrypt@5.1.1/node_modules/bcrypt install$ node-pre-gyp install --fallback-to-build
[21:56:18.695] .../sharp@0.33.5/node_modules/sharp install$ node install/check
[21:56:18.824] .../node_modules/utf-8-validate install: Done
[21:56:18.849] .../node_modules/bufferutil install: Done
[21:56:18.870] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info it worked if it ends with ok
[21:56:18.870] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info using node-pre-gyp@1.0.11
[21:56:18.871] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info using node@22.12.0 | linux | x64
[21:56:18.914] .../sharp@0.33.5/node_modules/sharp install: Done
[21:56:18.961] .../bcrypt@5.1.1/node_modules/bcrypt install: (node:175) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
[21:56:18.962] .../bcrypt@5.1.1/node_modules/bcrypt install: (Use `node --trace-deprecation ...` to show where the warning was created)
[21:56:18.962] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info check checked for "/vercel/path0/node_modules/.pnpm/bcrypt@5.1.1/node_modules/bcrypt/lib/binding/napi-v3/bcrypt_lib.node" (not found)
[21:56:18.962] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp http GET https://github.com/kelektiv/node.bcrypt.js/releases/download/v5.1.1/bcrypt_lib-v5.1.1-napi-v3-linux-x64-glibc.tar.gz
[21:56:19.104] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info install unpacking napi-v3/bcrypt_lib.node
[21:56:19.113] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info extracted file count: 1 
[21:56:19.113] .../bcrypt@5.1.1/node_modules/bcrypt install: node-pre-gyp info ok 
[21:56:19.114] .../bcrypt@5.1.1/node_modules/bcrypt install: [bcrypt] Success: "/vercel/path0/node_modules/.pnpm/bcrypt@5.1.1/node_modules/bcrypt/lib/binding/napi-v3/bcrypt_lib.node" is installed via remote
[21:56:19.119] .../bcrypt@5.1.1/node_modules/bcrypt install: Done
[21:56:19.193] 
[21:56:19.194] dependencies:
[21:56:19.194] + @heroicons/react 2.2.0
[21:56:19.194] + @tailwindcss/forms 0.5.9
[21:56:19.194] + @vercel/postgres 0.10.0
[21:56:19.194] + autoprefixer 10.4.20
[21:56:19.194] + bcrypt 5.1.1
[21:56:19.194] + clsx 2.1.1
[21:56:19.194] + next 15.1.2
[21:56:19.194] + next-auth 5.0.0-beta.19
[21:56:19.194] + postcss 8.4.49
[21:56:19.194] + react 19.0.0
[21:56:19.194] + react-dom 19.0.0
[21:56:19.194] + tailwindcss 3.4.16
[21:56:19.194] + typescript 5.7.2
[21:56:19.194] + use-debounce 10.0.4
[21:56:19.194] + zod 3.23.8
[21:56:19.194] 
[21:56:19.194] devDependencies:
[21:56:19.194] + @types/bcrypt 5.0.2
[21:56:19.194] + @types/node 22.10.1
[21:56:19.194] + @types/react 19.0.0
[21:56:19.194] + @types/react-dom 19.0.0
[21:56:19.194] 
[21:56:19.203] Done in 7.6s
[21:56:19.272] Detected Next.js version: 15.1.2
[21:56:19.279] Running "pnpm run build"
[21:56:19.791] 
[21:56:19.791] > @ build /vercel/path0
[21:56:19.792] > next build
[21:56:19.792] 
[21:56:20.563] Attention: Next.js now collects completely anonymous telemetry regarding usage.
[21:56:20.563] This information is used to shape Next.js' roadmap and prioritize features.
[21:56:20.563] You can learn more, including how to opt-out if you'd not like to participate in this anonymous program, by visiting the following URL:
[21:56:20.564] https://nextjs.org/telemetry
[21:56:20.564] 
[21:56:20.677]    ▲ Next.js 15.1.2
[21:56:20.677] 
[21:56:20.704]    Creating an optimized production build ...
[21:56:22.862] (node:268) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
[21:56:22.863] (Use `node --trace-deprecation ...` to show where the warning was created)
[21:56:27.623] (node:320) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
[21:56:27.624] (Use `node --trace-deprecation ...` to show where the warning was created)
[21:56:30.548]  ✓ Compiled successfully
[21:56:30.552]    Linting and checking validity of types ...
[21:56:34.023] Failed to compile.
[21:56:34.023] 
[21:56:34.024] ./app/lib/data.ts:69:37
[21:56:34.024] Type error: Object is of type 'unknown'.
[21:56:34.024] 
[21:56:34.024] �[0m �[90m 67 |�[39m     ])�[33m;�[39m�[0m
[21:56:34.024] �[0m �[90m 68 |�[39m�[0m
[21:56:34.024] �[0m�[31m�[1m>�[22m�[39m�[90m 69 |�[39m     �[36mconst�[39m numberOfInvoices �[33m=�[39m �[33mNumber�[39m(data[�[35m0�[39m]�[33m.�[39mrows[�[35m0�[39m]�[33m.�[39mcount �[33m?�[39m�[33m?�[39m �[32m'0'�[39m)�[33m;�[39m�[0m
[21:56:34.024] �[0m �[90m    |�[39m                                     �[31m�[1m^�[22m�[39m�[0m
[21:56:34.024] �[0m �[90m 70 |�[39m     �[36mconst�[39m numberOfCustomers �[33m=�[39m �[33mNumber�[39m(data[�[35m1�[39m]�[33m.�[39mrows[�[35m0�[39m]�[33m.�[39mcount �[33m?�[39m�[33m?�[39m �[32m'0'�[39m)�[33m;�[39m�[0m
[21:56:34.024] �[0m �[90m 71 |�[39m     �[36mconst�[39m totalPaidInvoices �[33m=�[39m formatCurrency(data[�[35m2�[39m]�[33m.�[39mrows[�[35m0�[39m]�[33m.�[39mpaid �[33m?�[39m�[33m?�[39m �[32m'0'�[39m)�[33m;�[39m�[0m
[21:56:34.024] �[0m �[90m 72 |�[39m     �[36mconst�[39m totalPendingInvoices �[33m=�[39m formatCurrency(data[�[35m2�[39m]�[33m.�[39mrows[�[35m0�[39m]�[33m.�[39mpending �[33m?�[39m�[33m?�[39m �[32m'0'�[39m)�[33m;�[39m�[0m
[21:56:34.055]  ELIFECYCLE  Command failed with exit code 1.
[21:56:34.079] Error: Command "pnpm run build" exited with 1
[21:56:34.
386]

Additional information

No response

Example

No response

[icyJoseph]

You have a TypeScript error, not a lint error.

Most likely, you use a different version in your text editor.

• https://nextjs.org/docs/app/getting-started/installation#ide-plugin

If you use VSCode, make sure that VSCode picks up TypeScript from your project, and not its own version. The link above should help with that.

That being said, when data is of type unknown, you can't just index them, as in, data.foo for example. You have to narrow down from unknown into a record, object, class, etc, in which a foo property exists. Post more info about the place where this error happens, and also fix your IDE, so that you don't have to wait for builds to see these errors, and rather see them as you work on your text editor.