diff --git a/.changeset/brown-months-fry.md b/.changeset/brown-months-fry.md new file mode 100644 index 000000000000..a95410d97668 --- /dev/null +++ b/.changeset/brown-months-fry.md @@ -0,0 +1,5 @@ +--- +'svelte': patch +--- + +chore: treeshake unused store subscriptions in SSR mode diff --git a/packages/svelte/src/compiler/phases/3-transform/server/transform-server.js b/packages/svelte/src/compiler/phases/3-transform/server/transform-server.js index cc2d0ad95cc1..5640a1f372a9 100644 --- a/packages/svelte/src/compiler/phases/3-transform/server/transform-server.js +++ b/packages/svelte/src/compiler/phases/3-transform/server/transform-server.js @@ -322,7 +322,7 @@ function serialize_get_binding(node, state) { const store_id = b.id(node.name.slice(1)); return b.call( '$.store_get', - b.id('$$store_subs'), + b.assignment('??=', b.id('$$store_subs'), b.object([])), b.literal(node.name), serialize_get_binding(store_id, state) ); @@ -460,7 +460,7 @@ function serialize_set_binding(node, context, fallback) { } else if (is_store) { return b.call( '$.mutate_store', - b.id('$$store_subs'), + b.assignment('??=', b.id('$$store_subs'), b.object([])), b.literal(left.name), b.id(left_name), b.assignment(node.operator, /** @type {import('estree').Pattern} */ (visit(node.left)), value) @@ -506,7 +506,11 @@ const global_visitors = { if (node.prefix) fn += '_pre'; /** @type {import('estree').Expression[]} */ - const args = [b.id('$$store_subs'), b.literal(argument.name), b.id(argument.name.slice(1))]; + const args = [ + b.assignment('??=', b.id('$$store_subs'), b.object([])), + b.literal(argument.name), + b.id(argument.name.slice(1)) + ]; if (node.operator === '--') { args.push(b.literal(-1)); } @@ -2094,8 +2098,10 @@ export function server_component(analysis, options) { (binding) => binding.kind === 'store_sub' ) ) { - instance.body.unshift(b.const('$$store_subs', b.object([]))); - template.body.push(b.stmt(b.call('$.unsubscribe_stores', b.id('$$store_subs')))); + instance.body.unshift(b.var('$$store_subs')); + template.body.push( + b.if(b.id('$$store_subs'), b.stmt(b.call('$.unsubscribe_stores', b.id('$$store_subs')))) + ); } // Propagate values of bound props upwards if they're undefined in the parent and have a value. // Don't do this as part of the props retrieval because people could eagerly mutate the prop in the instance script.