rc.21 regrade: DV-19 (latest of a shown guess, per solidjs/solid#4695), count read under its region, guide and harness follow-ups

eval/README.md

@@ -98,7 +98,10 @@ mutants/   naive React drafts the hidden tests must catch
 results/   scored runs
 ```
 
-Setup: `npm install` here (Solid 2.0.0-rc.21 from npm); `cargo build --release --bin rxc` in `../compiler` (its Solid pin is d2323b0, rc.19).
+Setup: `npm install` here (Solid 2.0.0-rc.21 and Playwright from npm; set `CHROMIUM=/path/to/chromium` to drive a
+system browser instead of Playwright's download); `cargo build --release --bin rxc` in `../compiler` (its Solid pin
+is `ref/SOLID_NEXT`). A round is regradable only if its runs' sources are committed under `results/<round>/runs/`
+(rounds 5, 7, 10 and 11 kept theirs in the session that ran them and cannot be regraded).
 `RXC` and `RT_WEB` override the paths to the binary and `ref/compile/rt-web.ts`. (The pilot itself ran on PR #6's
 crate before it merged, built with the same pin.)
 

eval/harness/driver.mjs

@@ -22,7 +22,8 @@ export async function serve(dist) {
   return { url: `http://127.0.0.1:${http.address().port}/`, close: () => http.close() };
 }
 
-export async function launch() { return chromium.launch(); }
+/** CHROMIUM=/path/to/chromium drives a system browser (NixOS and the like, where Playwright's download does not run). */
+export async function launch() { return chromium.launch(process.env.CHROMIUM ? { executablePath: process.env.CHROMIUM } : {}); }
 
 /** One test: a fresh page on the app, `run(app)` with the helpers below. Returns { ok, error }. */
 export async function runTest(browser, url, test) {

eval/package.json

@@ -17,6 +17,7 @@
     "eslint-plugin-react-hooks": "7.0.0",
     "eslint-plugin-solid": "^0.18.1",
     "foldkit": "^0.170.0",
+    "playwright": "1.64.1",
     "react": "19.2.0",
     "react-dom": "19.2.0",
     "solid-js": "2.0.0-rc.21",

eval/reference/chain2/rx/issues.rx

@@ -9,6 +9,14 @@ export error NotFound(id: number) => `issue #${id} not found`
 
 fn found(it, id: number) => it == null ? throw NotFound(id) : it
 
+// the open list as shown (closes in flight already out of it) is the tab's count: it is read where the list is read,
+// under the list's boundary, so it holds and reveals with the rows; other lists, loads and failures leave it as it was
+component OpenCount(props: { n: number; onCount: (n: number) => void }) {
+  effect (props.n) {
+    props.onCount($0)
+  }
+}
+
 export component IssuesPage(props: { onOpenCount: (n: number) => void }) {
   source user: string := "guest"
   source filter: string := "open"
@@ -20,13 +28,6 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void }) {
   source renameError: string = ""
   source closeError: string = ""
 
-  // the open list as shown (closes in flight already out of it) is the tab's count; other lists, loads and failures
-  // leave the count as it was
-  effect ((filter == "open" ? issues.length : -1) catch (e) => -1) {
-    if ($0 >= 0) {
-      props.onOpenCount($0)
-    }
-  }
 
   action assignTo(id: number, who: string) {
     optimistic assignError := ""
@@ -83,6 +84,9 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void }) {
     <div data-testid="list">
       {loading on(filter) fallback { <p>loading {latest filter} issues</p> } {
         {errored fallback(e) { <p>list error: {e.message}</p> } {
+          {if filter == "open" {
+            <OpenCount n={issues.length} onCount={n => { props.onOpenCount(n) }} />
+          }}
           <ul>
             {for it in issues {
               <li data-testid="issue" onClick={() => {

eval/reference/chain3/rx/issues.rx

@@ -10,6 +10,14 @@ export error NotFound(id: number) => `issue #${id} not found`
 
 fn found(it, id: number) => it == null ? throw NotFound(id) : it
 
+// the open list as shown (closes in flight already out of it) is the tab's count: it is read where the list is read,
+// under the list's boundary, so it holds and reveals with the rows; other lists, loads and failures leave it as it was
+component OpenCount(props: { n: number; onCount: (n: number) => void }) {
+  effect (props.n) {
+    props.onCount($0)
+  }
+}
+
 export component IssuesPage(props: { onOpenCount: (n: number) => void; onOpenHelp: (query: string, id: number) => void }) {
   source user: string := "guest"
   source filter: string := "open"
@@ -21,13 +29,6 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void; onOpenHel
   source renameError: string = ""
   source closeError: string = ""
 
-  // the open list as shown (closes in flight already out of it) is the tab's count; other lists, loads and failures
-  // leave the count as it was
-  effect ((filter == "open" ? issues.length : -1) catch (e) => -1) {
-    if ($0 >= 0) {
-      props.onOpenCount($0)
-    }
-  }
 
   action assignTo(id: number, who: string) {
     optimistic assignError := ""
@@ -84,6 +85,9 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void; onOpenHel
     <div data-testid="list">
       {loading on(filter) fallback { <p>loading {latest filter} issues</p> } {
         {errored fallback(e) { <p>list error: {e.message}</p> } {
+          {if filter == "open" {
+            <OpenCount n={issues.length} onCount={n => { props.onOpenCount(n) }} />
+          }}
           <ul>
             {for it in issues {
               <li data-testid="issue" onClick={() => {

eval/reference/chain4/rx/issues.rx

@@ -10,6 +10,14 @@ export error NotFound(id: number) => `issue #${id} not found`
 
 fn found(it, id: number) => it == null ? throw NotFound(id) : it
 
+// the open list as shown (closes in flight already out of it) is the tab's count: it is read where the list is read,
+// under the list's boundary, so it holds and reveals with the rows; other lists, loads and failures leave it as it was
+component OpenCount(props: { n: number; onCount: (n: number) => void }) {
+  effect (props.n) {
+    props.onCount($0)
+  }
+}
+
 export component IssuesPage(props: { onOpenCount: (n: number) => void; onOpenHelp: (query: string, id: number) => void }) {
   source user: string := "guest"
   source filter: string := "open"
@@ -23,13 +31,6 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void; onOpenHel
   // the newest row action's failure; row actions and the detail's leave each other's errors alone
   source rowError: string = ""
 
-  // the open list as shown (closes in flight already out of it) is the tab's count; other lists, loads and failures
-  // leave the count as it was
-  effect ((filter == "open" ? issues.length : -1) catch (e) => -1) {
-    if ($0 >= 0) {
-      props.onOpenCount($0)
-    }
-  }
 
   action assignTo(id: number, who: string, fromRow: boolean) {
     if (fromRow) {
@@ -105,6 +106,9 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void; onOpenHel
     <div data-testid="list">
       {loading on(filter) fallback { <p>loading {latest filter} issues</p> } {
         {errored fallback(e) { <p>list error: {e.message}</p> } {
+          {if filter == "open" {
+            <OpenCount n={issues.length} onCount={n => { props.onOpenCount(n) }} />
+          }}
           <ul>
             {for it in issues {
               <li>

eval/reference/count/rx/issues.rx

@@ -8,6 +8,14 @@ export error NotFound(id: number) => `issue #${id} not found`
 
 fn found(it, id: number) => it == null ? throw NotFound(id) : it
 
+// the open list as shown (closes in flight already out of it) is the tab's count: it is read where the list is read,
+// under the list's boundary, so it holds and reveals with the rows; other lists, loads and failures leave it as it was
+component OpenCount(props: { n: number; onCount: (n: number) => void }) {
+  effect (props.n) {
+    props.onCount($0)
+  }
+}
+
 export component IssuesPage(props: { onOpenCount: (n: number) => void }) {
   source user: string := "guest"
   source filter: string := "open"
@@ -19,13 +27,6 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void }) {
   source renameError: string = ""
   source closeError: string = ""
 
-  // the open list as shown (closes in flight already out of it) is the tab's count; other lists, loads and failures
-  // leave the count as it was
-  effect ((filter == "open" ? issues.length : -1) catch (e) => -1) {
-    if ($0 >= 0) {
-      props.onOpenCount($0)
-    }
-  }
 
   action assignTo(id: number, who: string) {
     optimistic assignError := ""
@@ -82,6 +83,9 @@ export component IssuesPage(props: { onOpenCount: (n: number) => void }) {
     <div data-testid="list">
       {loading on(filter) fallback { <p>loading {latest filter} issues</p> } {
         {errored fallback(e) { <p>list error: {e.message}</p> } {
+          {if filter == "open" {
+            <OpenCount n={issues.length} onCount={n => { props.onOpenCount(n) }} />
+          }}
           <ul>
             {for it in issues {
               <li data-testid="issue" onClick={() => {

eval/results/rc21-regrade-2026-11-05/README.md

@@ -0,0 +1,72 @@
+# Regrade on Solid 2.0.0-rc.21 (2026-11-05, not a round)
+
+The rc.21 repin (41a6b1f) carried the fixes for every Solid issue the eval had filed but did not rerun anything. This
+regrades what the repository holds, with rc.21 from npm and `rxc` from this commit. Round 10's and round 11's desks are
+not in the repository (their run directories stayed in the session that ran them), so they are not here.
+
+## References on the desk9 brief (`harness/grade.sh`: hidden, overlap, 20 fuzz seeds)
+
+| app | hidden | overlap | fuzz seeds with a hole |
+| --- | --- | --- | --- |
+| chain4 .rx (count read with `latest issues`) | 77/77 | 38/38 | 3 |
+| chain4 .rx (count read under the list's region) | 77/77 | 38/38 | 2 |
+| chain4 React | 77/77 | 38/38 | 0 |
+| recipe React (TanStack's optimistic-updates guide) | 77/77 | 22/38 | 7 |
+
+The recipe React desk scores what round 9 recorded for it (22/38), so this setup grades as the rounds did. The chain4
+.rx reference passes every hidden and overlap test, including "retry after not found" (#4425, #4627), which failed in
+every .rx run from round 5 on.
+
+The `latest issues` reference's three fuzz holes, replayed:
+
+| seed | hole | cause | owner |
+| --- | --- | --- | --- |
+| 1 | the tab count shows 3 beside 2 rows, a close in flight | `latest issues` answers the re-asked truth, not the guess, once a list refresh lands under a pending close | Solid: `latest` should keep a shown guess until its hold commits (solidjs/solid#4689, ruled in #4695 decision 3, not built; DV-19) |
+| 11 | an accepted rename's row shows the old title until the refresh lands | the row was not in the list when the rename was sent (`findIndex` -1): nothing was guessed on it | the app; `guide/async.md` §4 now says so |
+| 15 | an accepted rename's detail heading shows the old title until the refresh lands | the detail was still loading when the rename was sent: nothing was guessed on it (the row guess held) | the app; the same |
+
+Seed 1 was the reference as the checker suggested it: CN-3e refuses the count effect's read of `issues` outside the
+`loading on(filter)` region and suggests `latest issues`. Four references (chain2, chain3, chain4, count) had the
+outside read, predating the rule. By the spec (and Solid's own ruling, #4695 decision 3) `latest issues` answers the
+guess the list shows, so that program is right and the hole is Solid's (DV-19, #4689, not built). The references
+read the count where the list is read instead, in a small component under the list's region: it holds and reveals
+with the rows, it is equally right by the spec, it does not depend on #4689, and it is what 10 of 12 agent desks in
+rounds 10 and 11 wrote. With it, chain4 has two fuzz holes, both the app's (seeds 11 and 15), and chain2, chain3 and
+count pass their own tasks' hidden and overlap tests (`graded/`).
+
+Reducing seed 15 turned up a second Solid bug, solidjs/solid#4690: with nothing rendering a store, an effect reading it
+sees a guess revert at the action's end, before the action's refresh lands, once an outside re-ask has landed under it.
+A rendered reader keeps the guess, and so does an effect beside one; an effect over a source nothing renders reaches
+it (DV-20, S-guess-reask-refresh's effect-only variant; `ref/oracle/repros/4690-guess-reask-refresh.mjs`). Fixed on
+`next` (Ryan, 2026-11-05); recorded until the repin.
+
+## Round 4's .rx apps (18, `results/change-2026-10-28/runs`) on rc.21 and this `rxc`
+
+| | runs |
+| --- | --- |
+| pass every hidden and overlap test | 14 |
+| refused by `STALE_WRITE_BACK` (AC-1e, added after round 4) | 3: small close-rx-1, small comments-rx-2, frontier rename-rx-3 |
+| one overlap test failed | 1: small rename-rx-1, a guess on `detail` with `refresh issues` only |
+
+The three refusals are the three the round 4 write-up predicted. The one failure is the shape `guide/async.md` §4 now
+names ("refresh every question you guessed on"). Nothing in round 4's residue is Solid's.
+
+## Reference suites on rc.21
+
+Interpreter 114 pass; oracle and compiled 114 pass, 6 recorded divergences (DV-19 at four instants, DV-20 at two);
+server render 107 pass, 7 skip (not rerun after the review fixes); types 156 pass; the crate agrees with ref/ on 321/321 programs.
+
+S-store-8 (two actions' guesses on one row; a declined one reverts alone) had failed on the interpreter since the
+commit that added it (edb76be): the interpreter kept one guess per node with one owner, so the newer action's guess took
+the row and the older action's decline found nothing of its own to revert. Guesses are now entries per key and hold
+(`ref/src/runtime.ts`), as H-11 says; the same-key variant added to S-store-8 passes on all three runners. A new answer that corrects a guess (D-34) marks
+the action's entry spent instead of dropping it, so the action's re-ask still holds the corrected guess (D-35): with
+the entry dropped, a closed row came back between the write landing and the re-ask (S-latest-reask's variant, `4 / 4`
+for `2 / 4`; Solid shows `2 / 4`). The interpreter now follows #4695's D-34: a landing answer is compared with the guess (before,
+only one that changed the truth corrected), the correction re-derives the graph, and the screen, the guess's effects
+and `latest` of a shown guess keep it until the hold commits.
+
+## Setup
+
+`eval/package.json` now lists Playwright; `CHROMIUM=/path/to/chromium` drives a system browser in `harness/driver.mjs`
+and `ref/ssr/run.ts`. `graded/`: the grade output per app above, and `round4-<tier>-<run>.txt` per round 4 app.

eval/results/rc21-regrade-2026-11-05/graded/chain2-rx.txt

@@ -0,0 +1,4 @@
+== hidden
+64/64 passed
+== overlap
+29/29 passed

eval/results/rc21-regrade-2026-11-05/graded/chain3-rx.txt

@@ -0,0 +1,4 @@
+== hidden
+70/70 passed
+== overlap
+32/32 passed

eval/results/rc21-regrade-2026-11-05/graded/chain4-react.txt

@@ -0,0 +1,6 @@
+== hidden
+77/77 passed
+== overlap
+38/38 passed
+== fuzz
+chain4-react: 0/20 seeds found a hole

eval/results/rc21-regrade-2026-11-05/graded/chain4-rx.txt

@@ -0,0 +1,10 @@
+== hidden
+77/77 passed
+== overlap
+38/38 passed
+== fuzz
+chain4-rx: 2/20 seeds found a hole
+  seed 11 step 33: row title: #4 shows "Typo in footer", server "Delta"
+    tab help ; tab issues ; tab help ; land fetchIssues:open ; tab issues ; focus ; tab help ; tab issues ; land fetchIssues:open ; row-assign 1 ; land assign:3,guest ; filter closed ; user ann ; row-assign 0 ; focus ; land fetchIssues:open ; land assign:1,ann ; select #4 ; close ; land fetchIssues:closed ; close ; land fetchComments:4 ; fail fetchLabels:4 ; row-assign 0 ; close ; land fetchIssue:
+  seed 15 step 24: detail title: "#2 Old buglong gonesaving filescrash reportsretryassign to g", server "Bravo"
+    land fetchIssues:open ; row-assign 0 ; focus ; land assign:1,guest ; fail fetchIssues:open ; tab help ; tab issues ; land fetchIssues:open ; focus ; filter closed ; land fetchIssues:closed ; select #2 ; land fetchComments:2 ; rename Bravo ; select #2 ; assign ; land fetchIssue:2 ; row-assign 0 ; select #2 ; land fetchLabels:2 ; assign ; remove-label 0 ; land search:Old bug ; land renameIssue:2

eval/results/rc21-regrade-2026-11-05/graded/count-rx.txt

@@ -0,0 +1,4 @@
+== hidden
+56/56 passed
+== overlap
+24/24 passed