refactor(core): share WASM cell-kind wire tags

.changeset/calm-tables-share.md

@@ -0,0 +1,5 @@
+---
+"@sheetwrite/core": patch
+---
+
+Share cell-kind wire tags across the store, window reader, and paint worker to prevent internal WASM contract divergence.

packages/core/src/store/data-engine.ts

@@ -107,12 +107,12 @@ import { StoreSnapshotCodec } from "./snapshot-codec.js";
 import { StoreViewState } from "./view-state.js";
 import type { RecomputingCellStore } from "./wasm-contract.js";
 import { StoreWindowReader } from "./window-reader.js";
-
-// Mirror of the WASM cell tags.
-const KIND_NUMBER = 1;
-const KIND_STRING = 2;
-const KIND_BOOL = 3;
-const KIND_FORMULA = 4;
+/**
+ * Cell kinds cross the WASM boundary in bulk paths here.
+ * Shared tags keep these encodings aligned with window reads
+ * and the paint worker.
+ */
+import { KIND_BOOL, KIND_FORMULA, KIND_NUMBER, KIND_STRING } from "./wire-tags.js";
 
 const AGG_OP: Record<AggregateOp, number> = { sum: 0, avg: 1, min: 2, max: 3, count: 4 };
 

packages/core/src/store/window-reader.ts

@@ -5,11 +5,10 @@ import type { SheetId } from "../types/coordinates.js";
 import type { Workbook } from "../types/document.js";
 import type { ResourceOwnerBytes, VisibleWindowView } from "../types/store.js";
 import type { ConsumingWindowView, RecomputingCellStore } from "./wasm-contract.js";
+import { KIND_BOOL, KIND_NUMBER, KIND_STRING, NO_STRING } from "./wire-tags.js";
 
-const KIND_NUMBER = 1;
-const KIND_STRING = 2;
-const KIND_BOOL = 3;
 const EMPTY_COND_MATCHES = new Uint32Array(0);
+// Kept independent from the worker cache cap so each thread can be tuned separately.
 const STRING_CACHE_CAP = 65_536;
 const WINDOW_SCRATCH_MAX_REUSE = 65_536;
 const CONDITIONAL_MASK_BITS = Uint32Array.BYTES_PER_ELEMENT * 8;
@@ -264,7 +263,7 @@ export class StoreWindowReader {
 
     for (let i = 0; i < stringIds.length; i++) {
       const id = stringIds[i];
-      if (id !== undefined && id !== 0xffffffff && !this.stringCache.has(id)) {
+      if (id !== undefined && id !== NO_STRING && !this.stringCache.has(id)) {
         if (!missingIdSet) missingIdSet = new Set<number>();
         missingIdSet.add(id);
       }
@@ -284,7 +283,7 @@ export class StoreWindowReader {
         poolStringBytes,
       );
       for (let i = 0; i < stringPoolUpdateValues.length; i++) {
-        this.stringCache.set(stringPoolUpdateIds[i] ?? 0xffffffff, stringPoolUpdateValues[i] ?? "");
+        this.stringCache.set(stringPoolUpdateIds[i] ?? NO_STRING, stringPoolUpdateValues[i] ?? "");
       }
     }
 
@@ -295,8 +294,8 @@ export class StoreWindowReader {
       } else if (kinds[i] === KIND_BOOL) {
         values[i] = (numbers[i] ?? 0) !== 0;
       } else if (kinds[i] === KIND_STRING) {
-        const poolId = stringIds[i] ?? 0xffffffff;
-        if (poolId !== 0xffffffff) {
+        const poolId = stringIds[i] ?? NO_STRING;
+        if (poolId !== NO_STRING) {
           values[i] = this.stringCache.get(poolId) ?? null;
         } else {
           const stringSlot = stringIndex[i] ?? -1;

packages/core/src/store/wire-tags.ts

@@ -0,0 +1,15 @@
+// These values mirror packages/wasm/src/types.rs and must change together.
+export const KIND_EMPTY = 0 as const;
+export const KIND_NUMBER = 1 as const;
+export const KIND_STRING = 2 as const;
+export const KIND_BOOL = 3 as const;
+export const KIND_FORMULA = 4 as const;
+
+export const NO_STRING = 0xffffffff as const;
+
+export type CellKindTag =
+  | typeof KIND_EMPTY
+  | typeof KIND_NUMBER
+  | typeof KIND_STRING
+  | typeof KIND_BOOL
+  | typeof KIND_FORMULA;

packages/core/src/worker.ts

@@ -3,6 +3,7 @@
 // busy main thread can't stall scrolling. Custom (function) cell renderers do
 // not cross the worker boundary, so the registry here is always empty.
 import { blitVerticalScroll, paintFrame, paintFreezeDivider } from "./canvas-paint.js";
+import { KIND_NUMBER, KIND_STRING, NO_STRING } from "./store/wire-tags.js";
 import type { CellScalar } from "./types/cell.js";
 import type { CellRenderer, RenderLayout, Theme, Viewport } from "./types/render.js";
 import type { VisibleWindowView } from "./types/store.js";
@@ -85,16 +86,15 @@ type WorkerMessage =
   | { type: "destroy" };
 
 const NO_RENDERERS: ReadonlyMap<string, CellRenderer> = new Map();
-const KIND_NUMBER = 1;
-const KIND_STRING = 2;
-const NO_STRING = 0xffffffff;
 
 /**
  * Hard cap on the pool-id→string cache, mirroring `SheetwriteStore`. A full-sheet
  * sweep would otherwise grow it to O(distinct strings), duplicating the WASM
  * string pool on the JS heap. At the cap we drop it wholesale and re-warm from
  * this frame's `stringPoolUpdate*` payload — cheap and self-healing.
  */
+// Kept independent from the host reader's cache cap:
+// each thread can be tuned separately.
 const STRING_CACHE_CAP = 65_536;
 
 interface WorkerRuntimeState {

packages/core/test/wire-tags.test.ts

@@ -0,0 +1,42 @@
+import { beforeAll, describe, expect, it } from "bun:test";
+import { initSheetwrite } from "../src/grid.js";
+import { KIND_BOOL, KIND_NUMBER, KIND_STRING, NO_STRING } from "../src/store/wire-tags.js";
+import { SheetwriteStore } from "../src/store.js";
+import { makeWorkbook } from "./fixtures.js";
+
+beforeAll(async () => {
+  await initSheetwrite();
+});
+
+describe("cell-kind wire tags", () => {
+  it("matches the tags and string sentinel produced by the WASM store", () => {
+    const store = new SheetwriteStore(makeWorkbook(1));
+    try {
+      store.applyTransaction({
+        patches: [
+          {
+            op: "set",
+            addr: { sheet: "s1", row: 0, col: 0 },
+            value: { kind: "literal", value: 42 },
+          },
+          {
+            op: "set",
+            addr: { sheet: "s1", row: 0, col: 1 },
+            value: { kind: "literal", value: "alpha" },
+          },
+          {
+            op: "set",
+            addr: { sheet: "s1", row: 0, col: 2 },
+            value: { kind: "literal", value: true },
+          },
+        ],
+      });
+
+      const view = store.getVisibleWindow("s1", { start: 0, end: 1 }, [0, 1, 2]);
+      expect(Array.from(view.valueKinds ?? [])).toEqual([KIND_NUMBER, KIND_STRING, KIND_BOOL]);
+      expect(view.stringPoolIds?.[0]).toBe(NO_STRING);
+    } finally {
+      store.dispose();
+    }
+  });
+});

packages/wasm/src/types.rs

@@ -8,6 +8,8 @@ use crate::eval::expand_let_reachable_ast;
 use crate::memory::MemoryOwnerStats;
 use std::rc::Rc;
 
+// TypeScript mirrors these values in packages/core/src/store/wire-tags.ts;
+// packages/core/test/wire-tags.test.ts enforces the pairing.
 pub(crate) const KIND_EMPTY: u8 = 0;
 pub(crate) const KIND_NUMBER: u8 = 1;
 pub(crate) const KIND_STRING: u8 = 2;

scripts/check-import-cycles.ts

@@ -37,13 +37,15 @@ const STORE_EDGES: Readonly<Record<string, readonly string[]>> = {
     "../types/store.ts",
   ],
   "wasm-contract.ts": [],
+  "wire-tags.ts": [],
   "window-reader.ts": [
     "../style-dictionary.ts",
     "../types/cell.ts",
     "../types/coordinates.ts",
     "../types/document.ts",
     "../types/store.ts",
     "wasm-contract.ts",
+    "wire-tags.ts",
   ],
 };
 

scripts/coverage-thresholds.json

@@ -639,7 +639,8 @@
         "packages/core/src/store/ranges.ts",
         "packages/core/src/store/snapshot-codec.ts",
         "packages/core/src/store/view-state.ts",
-        "packages/core/src/store/window-reader.ts"
+        "packages/core/src/store/window-reader.ts",
+        "packages/core/src/store/wire-tags.ts"
       ],
       "language": "typescript",
       "tier": "B",