Package not working with Svelte@5.19.10

[IgorMitev]

Hello,

Tried the package as a replacement for single-spa-svelte for a Svelte 5 project, could not get it to work with version 5.20.0, issues went away after downgrading Svelte to an earlier 5 version .

The issue appeared from Svelte@5.19.10, can confirm by running the repo tests and also in the other project.

Svelte@5.19.10

 ❯ src/lib/index.test.ts (1)
   ❯ index (1)
     × Should export exactly the expected objects.
 ✓ src/lib/SspaParcel/SspaParcel.test.ts (6)
 ❯ src/lib/single-spa/single-spa.svelte.test.ts (0)

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Failed Suites 1 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

 FAIL  src/lib/single-spa/single-spa.svelte.test.ts [ src/lib/single-spa/single-spa.svelte.test.ts ]
TypeError: Cannot read properties of undefined (reading 'includes')
 ❯ validate_assignment node_modules/svelte/src/compiler/phases/2-analyze/visitors/shared/utils.js:42:24
 ❯ AssignmentExpression node_modules/svelte/src/compiler/phases/2-analyze/visitors/AssignmentExpression.js:11:2
 ❯ next node_modules/zimmerframe/src/walk.js:107:21
 ❯ _ node_modules/svelte/src/compiler/phases/2-analyze/index.js:126:3
 ❯ visit node_modules/zimmerframe/src/walk.js:101:13
 ❯ Object.next node_modules/zimmerframe/src/walk.js:63:23
 ❯ ExpressionStatement node_modules/svelte/src/compiler/phases/2-analyze/visitors/ExpressionStatement.js:37:10
 ❯ next node_modules/zimmerframe/src/walk.js:107:21
 ❯ _ node_modules/svelte/src/compiler/phases/2-analyze/index.js:126:3
 ❯ visit node_modules/zimmerframe/src/walk.js:101:13

Svelte@5.20.0

 ❯ src/lib/single-spa/single-spa.svelte.test.ts (0)
 ✓ src/lib/SspaParcel/SspaParcel.test.ts (6)
 ❯ src/lib/index.test.ts (1)
   ❯ index (1)
     × Should export exactly the expected objects.

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Failed Suites 1 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

 FAIL  src/lib/single-spa/single-spa.svelte.test.ts [ src/lib/single-spa/single-spa.svelte.test.ts ]
TypeError: Cannot read properties of undefined (reading 'some')
 ❯ validate_assignment node_modules/svelte/src/compiler/phases/2-analyze/visitors/shared/utils.js:45:24
 ❯ AssignmentExpression node_modules/svelte/src/compiler/phases/2-analyze/visitors/AssignmentExpression.js:11:2
 ❯ next node_modules/zimmerframe/src/walk.js:107:21
 ❯ _ node_modules/svelte/src/compiler/phases/2-analyze/index.js:126:3
 ❯ visit node_modules/zimmerframe/src/walk.js:101:13
 ❯ Object.next node_modules/zimmerframe/src/walk.js:63:23
 ❯ ExpressionStatement node_modules/svelte/src/compiler/phases/2-analyze/visitors/ExpressionStatement.js:37:10
 ❯ next node_modules/zimmerframe/src/walk.js:107:21
 ❯ _ node_modules/svelte/src/compiler/phases/2-analyze/index.js:126:3
 ❯ visit node_modules/zimmerframe/src/walk.js:101:13

Noticed similar issues in the Svelte repo.

[webJose]

Hello! Thanks for reporting and looking into this. Let's see what goes down at the Svelte side first.

[webJose]

It seems that the Svelte team is declaring the issue fixed with release v5.20.1 according to the first fix in sveltejs/svelte#15279.

The version should be available shortly. I'll test, and if unit tests pass, I'll close as complete. Please reopen if you continue to have issues.

[webJose]

Ok, tested with v5.20.1. All unit testing is passing. Closing.

Feel free to reopen if you think is worth it. Happy coding!

Oh, and BTW, I am creating a client-side Svelte router with some micro-frontend goodnesses ---> @wjfe/n-savant