Layout doesn't apply to index route when using programatic routing.

[stereosteve]

When using fs routing routes/artists/_layout.tsx will apply to both routes/artists/index.tsx and routes/artists/[name].tsx.

But if I disable fs routing and do this in main.tsx:

app
  .layout("/artists", ArtistsLayout)
  .get("/artists", (ctx) => {
    return ctx.render(<ArtistList />)
  })
  .get("/artists/:name", (ctx) => {
    const artist = {
      name: ctx.params.name || "???",
    }
    return ctx.render(<ArtistDetail artist={artist} />)
  })
  .get("/artists/:name/albums", (ctx) => {
    const artist = {
      name: ctx.params.name || "???",
    }
    return ctx.render(<div>artist: {artist.name} album list</div>)
  })

ArtistLayout will apply to /artists/:name and /artists/:name/albums but not to the /artists index route.

[bartlomieju]

Confirmed — this is a known issue in the segment tree matching logic.

The root cause is that .layout() and .get() use different includeLastSegment values when placing themselves in the segment tree:

• .layout("/artists", ArtistsLayout) uses includeLastSegment: true, so the layout is placed on the "artists" segment node
• .get("/artists", handler) uses includeLastSegment: false, so the route is placed on the root segment node

When the route handler collects its middleware chain via segmentToMiddlewares(), it walks up from its own segment (root) to collect layouts. Since the "artists" segment is a child of root (not a parent), the layout is never reached.

Child routes like /artists/:name work because their segment path traverses through the "artists" segment, picking up the layout along the way.

There's already an ignored test acknowledging this at packages/fresh/src/app_test.tsx:827:

Deno.test.ignore("App - .layout()", async () => {
  // ...
  // The `/foo` layout is not applied for GET `/foo`, is that correct?

The fix would be in how getOrCreateSegment resolves the segment for a route — when a route's pattern exactly matches a layout's pattern, it should be placed in the same segment.