Describe the bug
Prior to @sveltejs/kit@2.11.0 I was able to use the deserialize function in server side routes to parse the response returned by calling svelte kit action methods using fetch. If relevant, my specific use case is a route that runs automates filling out some forms for the user based on the response from an LLM. I use deserialize to parse the response from the action.
Attempting to upgrade to any version >= 2.11.0 (including latest 2.20.3 as of April 3) results in all server side usages of deserialize throwing the following error:
Cannot read properties of undefined (reading 'decoders')
TypeError: Cannot read properties of undefined (reading 'decoders')
at deserialize (/node_modules/@sveltejs/kit/src/runtime/app/forms.js:37:84)
at load (/src/routes/load/+page.server.js:17:74)
at async load_server_data (/node_modules/@sveltejs/kit/src/runtime/server/page/load_data.js:45:18)
at async Promise.all (index 1)
at async render_data (/node_modules/@sveltejs/kit/src/runtime/server/data/index.js:101:17)
at async resolve (/node_modules/@sveltejs/kit/src/runtime/server/respond.js:443:17)
at async respond (/node_modules/@sveltejs/kit/src/runtime/server/respond.js:329:20)
at async file:///node_modules/@sveltejs/kit/src/exports/vite/dev/index.js:521:22
I ran npm run build and npm run preview results in the same error as well.
deserialize still works when used client side (.svelte) files but does not work in any server.js/ts files.
Reproduction
Logs
Cannot read properties of undefined (reading 'decoders')
TypeError: Cannot read properties of undefined (reading 'decoders')
at deserialize (/node_modules/@sveltejs/kit/src/runtime/app/forms.js:37:84)
at load (/src/routes/load/+page.server.js:17:74)
at async load_server_data (/node_modules/@sveltejs/kit/src/runtime/server/page/load_data.js:45:18)
at async Promise.all (index 1)
at async render_data (/node_modules/@sveltejs/kit/src/runtime/server/data/index.js:101:17)
at async resolve (/node_modules/@sveltejs/kit/src/runtime/server/respond.js:443:17)
at async respond (/node_modules/@sveltejs/kit/src/runtime/server/respond.js:329:20)
at async file:///node_modules/@sveltejs/kit/src/exports/vite/dev/index.js:521:22
Cannot read properties of undefined (reading 'decoders')
TypeError: Cannot read properties of undefined (reading 'decoders')
at deserialize (file:///.svelte-kit/output/server/chunks/forms.js:6:50)
at load (file:///.svelte-kit/output/server/entries/pages/load/_page.server.js:12:37)
at async load_server_data (file:///.svelte-kit/output/server/index.js:621:18)
at async Promise.all (index 1)
at async render_data (file:///.svelte-kit/output/server/index.js:1965:19)
at async resolve2 (file:///.svelte-kit/output/server/index.js:2977:22)
at async respond (file:///.svelte-kit/output/server/index.js:2882:22)
at async file:///node_modules/@sveltejs/kit/src/exports/vite/preview/index.js:197:5System Info
System:
OS: Linux 5.15 Ubuntu 22.04.5 LTS 22.04.5 LTS (Jammy Jellyfish)
CPU: (8) x64 Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
Memory: 11.96 GB / 31.28 GB
Container: Yes
Shell: 5.8.1 - /usr/bin/zsh
Binaries:
Node: 22.13.1 - ~/.local/share/nodejs/bin/node
Yarn: 1.22.22 - ~/.local/share/nodejs/bin/yarn
npm: 10.9.2 - ~/.local/share/nodejs/bin/npm
pnpm: 9.1.0 - ~/.local/share/nodejs/bin/pnpm
Browsers:
Chrome: 135.0.7049.52
npmPackages:
@sveltejs/adapter-node: ^5.2.12 => 5.2.12
@sveltejs/kit: ^2.10.0 => 2.10.0
@sveltejs/vite-plugin-svelte: ^3.1.2 => 3.1.2
svelte: ^4.2.19 => 4.2.19
vite: ^5.4.10 => 5.4.11Severity
blocking an upgrade
Additional Information
Probably related to #13149
Describe the bug
Prior to @sveltejs/kit@2.11.0 I was able to use the
deserializefunction in server side routes to parse the response returned by calling svelte kit action methods using fetch. If relevant, my specific use case is a route that runs automates filling out some forms for the user based on the response from an LLM. I use deserialize to parse the response from the action.Attempting to upgrade to any version >= 2.11.0 (including latest 2.20.3 as of April 3) results in all server side usages of
deserializethrowing the following error:I ran
npm run buildandnpm run previewresults in the same error as well.deserializestill works when used client side (.svelte) files but does not work in anyserver.js/tsfiles.Reproduction
Logs
System Info
System: OS: Linux 5.15 Ubuntu 22.04.5 LTS 22.04.5 LTS (Jammy Jellyfish) CPU: (8) x64 Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz Memory: 11.96 GB / 31.28 GB Container: Yes Shell: 5.8.1 - /usr/bin/zsh Binaries: Node: 22.13.1 - ~/.local/share/nodejs/bin/node Yarn: 1.22.22 - ~/.local/share/nodejs/bin/yarn npm: 10.9.2 - ~/.local/share/nodejs/bin/npm pnpm: 9.1.0 - ~/.local/share/nodejs/bin/pnpm Browsers: Chrome: 135.0.7049.52 npmPackages: @sveltejs/adapter-node: ^5.2.12 => 5.2.12 @sveltejs/kit: ^2.10.0 => 2.10.0 @sveltejs/vite-plugin-svelte: ^3.1.2 => 3.1.2 svelte: ^4.2.19 => 4.2.19 vite: ^5.4.10 => 5.4.11Severity
blocking an upgrade
Additional Information
Probably related to #13149