fix(journal): surface variable eval errors

Collect and report failed declarations, failed tag modifier expressions, and
circular dependencies instead of swallowing them. Diagnostics are deduped,
logged with key/expression context, cleared on re-init, and exposed through
useJournalCompletions and the VariableView warning banner. A bad declaration
no longer aborts the rest of a cascade.

Reject malformed numeric literals in the tokenizer so inputs like "1.2.3"
throw instead of being truncated by parseFloat.

docs/variable-store-plan.md

@@ -0,0 +1,129 @@
+# Variable store — outstanding fixes
+
+Notes from an audit of the client-side variable / tag reactivity system:
+
+- `src/components/journal/var-reactivity.ts` — engine (dependency graph, base/mod
+  separation, threshold-gated tag activation, cascade).
+- `src/components/journal/variable-expression.ts` — expression evaluator.
+- `src/components/journal/command-dispatcher.ts` — `/set`, `/rolltag`, cascade.
+- `src/components/journal/completions.ts` — init + seed.
+- `src/components/stores/journalStream.ts` — replay + hydration rebuild.
+- `src/components/journal/types/var.tsx` — `var` message + reducer.
+
+## Already fixed (context)
+
+Commit `a26d53c` (`fix(journal): keep variable bases in the stream`):
+
+- Hydration double-counted active tag modifiers because the stream carried only
+  combined values. `var` messages now carry `base` alongside `value`, the store
+  keeps `variableBases`, and `rebuildReactivityFromStore` restores exact bases.
+- Seeding ran at import against an empty store (clobbering persisted values and
+  appending duplicate `var` messages on every load). It now runs after hydration
+  and only for keys absent from the store.
+
+The items below are still open.
+
+## Open issues
+
+### 1. Modifier and declaration errors are swallowed — ✅ fixed
+
+- **Where:** `computeInitialValues` (`catch {}`, "skip failed evaluations at init
+  time") and `applyTagMapActivations` (`catch {}`, "skip failed modifier") in
+  `var-reactivity.ts`; `initReactivity` throws are reduced to `console.warn` in
+  `completions.ts`.
+- **Symptom:** a typo'd declaration or modifier expression silently yields a
+  wrong value (often `0`) with no author-facing feedback.
+- **Fixed:** the engine now collects `ReactivityDiagnostic` entries for failed
+  declarations (`computeInitialValues`, `reevaluateDependents`), failed modifier
+  expressions (`applyTagMapActivations`), and circular declarations
+  (`initReactivity`). They are deduped, logged via `console.warn` with
+  key/expression/tag context, cleared on each `initReactivity`, and bridged into
+  a signal exposed as `useJournalCompletions().diagnostics()`. `VariableView`
+  renders them as a warning banner. A bad declaration no longer aborts the rest
+  of a cascade.
+
+### 2. `var del` does not reach the engine — medium
+
+- **Where:** reducer in `types/var.tsx` supports `action: "del"`; the parser
+  (`command-parser.ts`) has no `/del`; `var-reactivity.ts` never clears
+  `baseValues` and `rebuildReactivityFromStore` never removes stale keys.
+- **Symptom:** a deleted variable still resolves locally via `getCombined`,
+  because it reads `baseValues` first.
+- **Fix:** either wire a `/del` command and clear engine state (base + mods) on
+  delete, or drop `del` from the schema/reducer if it is intentionally unused.
+
+### 3. Reactivity is initialized once, at import — medium
+
+- **Where:** `bootstrapReactivity` in `completions.ts` runs `initReactivity`
+  once; nothing re-runs it when declare blocks change or a session/document is
+  switched.
+- **Also:** `DispatchContext.declarations` / `tagModifiers`
+  (`command-dispatcher.ts`) are declared but never read — a vestige of a
+  per-dispatch init that was never wired up.
+- **Symptom:** editing `role=declare` content requires a full reload; stale
+  graph/expressions persist.
+- **Fix:** expose a re-init entry point keyed to content/session changes, and
+  either use or remove the unused context fields.
+
+### 4. `lookup` contract disagrees with its docs — low
+
+- **Where:** `EvalContext.lookup` documents "Resolve `$var`", but
+  `parseFactor` calls `ctx.lookup(varName.slice(1))` (bare name), and every
+  caller re-adds `$`.
+- **Symptom:** a caller following the doc would key variables with `$` and
+  silently get `0`s.
+- **Fix:** update the doc comment to state the argument is the bare name (no
+  `$`), or stop stripping in `parseFactor` and update callers.
+
+### 5. Undefined variables evaluate to `0` — low
+
+- **Where:** `parseFactor` (`variable-expression.ts`) returns a numeric `0` for
+  an unresolved `$var`.
+- **Symptom:** `/set $hp $cn*5` (typo) silently sets `0` instead of failing.
+- **Fix:** consider erroring on unknown variables in `/set` context while
+  keeping lenient behavior for display/roll contexts, or warn.
+
+### 6. Tokenizer accepts malformed numbers — ✅ fixed
+
+- **Where:** the number branch of `tokenize` consumes `[0-9.]` greedily, so
+  `1.2.3` becomes one "number" and `parseFloat` truncates it.
+- **Fixed:** the tokenizer now validates the scanned chunk against
+  `^\d+(\.\d+)?$` and throws `Invalid number literal: "…"` instead of pushing a
+  silently-truncated value. The error propagates through the diagnostics channel
+  (#1) for declarations/modifiers and through `dispatchError` for `/set` and
+  `/roll`.
+
+### 7. `topoSortAffected` re-evaluates untouched declarations — low
+
+- **Where:** in `var-reactivity.ts`, the visit condition
+  `affected.has(dep) || declExprs.has(dep)` pulls declared dependencies that are
+  not in `affected` into the result.
+- **Symptom:** `reevaluateDependents` re-evaluates and re-publishes variables
+  that did not change. Mostly harmless, but noisy.
+- **Fix:** only visit/topologically order keys in `affected`.
+
+### 8. Failed `initReactivity` leaves partial state — low
+
+- **Where:** `initReactivity` populates `depGraph` / `declExprs` / `tagModMap`
+  before `checkCircular()` throws; `inFlight` is never cleared on re-init.
+- **Fix:** build into locals and commit on success, or roll back on failure.
+  Clear `inFlight` in `initReactivity`.
+
+### 9. Residual base / tagmap-target edges — low
+
+- **Base fallback:** `rebuildReactivityFromStore` falls back to the combined
+  `value` when a message has no `base`, which double-counts mods. In-repo
+  emitters always send `base`; only hand-crafted/external `var` messages hit
+  this.
+- **Tagmap targets:** rebuild derives activations from each source's *base*
+  tagmap (this fixed a feedback loop where a tagmap-valued target re-triggered
+  its own modifier on every rebuild). If a variable's effective count crosses a
+  threshold purely via mods, that activation is not reconstructed on hydration.
+  Revisit if tagmap-valued modifier targets come into use.
+
+## Suggested order
+
+1. #3 (re-init) and #2 (`del`) — correctness of engine lifecycle.
+2. #1 (diagnostics) — authoring feedback.
+3. #4–#8 — cleanup and hardening.
+4. #9 — only if the tagmap-target pattern is adopted.

src/cli/completions/variable-system.test.ts

@@ -40,6 +40,7 @@ import {
   getDeclExpr,
   extractDependencies,
   rebuildReactivityFromStore,
+  getReactivityDiagnostics,
 } from "../../components/journal/var-reactivity";
 import { parseInput } from "../../components/journal/command-parser";
 import {
@@ -396,6 +397,15 @@ describe("evaluateExpression", () => {
     ).toThrow("Unexpected end");
   });
 
+  test("throws on malformed number literals", () => {
+    expect(() =>
+      evaluateExpression("1.2.3", { lookup: () => undefined }),
+    ).toThrow("Invalid number literal");
+    expect(() =>
+      evaluateExpression("1.", { lookup: () => undefined }),
+    ).toThrow("Invalid number literal");
+  });
+
   test("handles decimal numbers", () => {
     const result = evaluateExpression("3.5 + 2.5", { lookup: () => undefined });
     expect(result.value).toEqual({ kind: "number", value: 6 });
@@ -574,6 +584,113 @@ describe("var-reactivity", () => {
     });
   });
 
+  describe("diagnostics", () => {
+    test("reports a declaration that fails to evaluate", () => {
+      const warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+      initReactivity({
+        declarations: [
+          { key: "$hp", expression: "10 + 5" },
+          { key: "$bad", expression: "#warrior * 2" },
+        ],
+        tagModifiers: [],
+      });
+
+      const results = computeInitialValues(store());
+      expect(results.find((r) => r.key === "$hp")?.value).toBe("15");
+      expect(results.find((r) => r.key === "$bad")).toBeUndefined();
+
+      const diags = getReactivityDiagnostics();
+      expect(diags).toHaveLength(1);
+      expect(diags[0].kind).toBe("declaration");
+      expect(diags[0].key).toBe("$bad");
+      expect(diags[0].expression).toBe("#warrior * 2");
+      warn.mockRestore();
+    });
+
+    test("dedupes repeated failures of the same expression", () => {
+      const warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+      initReactivity({
+        declarations: [{ key: "$bad", expression: "#warrior * 2" }],
+        tagModifiers: [],
+      });
+
+      computeInitialValues(store());
+      computeInitialValues(store());
+      expect(getReactivityDiagnostics()).toHaveLength(1);
+      warn.mockRestore();
+    });
+
+    test("clears diagnostics on re-init", () => {
+      const warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+      initReactivity({
+        declarations: [{ key: "$bad", expression: "#warrior * 2" }],
+        tagModifiers: [],
+      });
+      computeInitialValues(store());
+      expect(getReactivityDiagnostics()).toHaveLength(1);
+
+      initReactivity({ declarations: [], tagModifiers: [] });
+      expect(getReactivityDiagnostics()).toHaveLength(0);
+      warn.mockRestore();
+    });
+
+    test("records a diagnostic when declarations are circular", () => {
+      const warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+      expect(() =>
+        initReactivity({
+          declarations: [
+            { key: "$a", expression: "$b + 1" },
+            { key: "$b", expression: "$a + 1" },
+          ],
+          tagModifiers: [],
+        }),
+      ).toThrow();
+
+      const diags = getReactivityDiagnostics();
+      expect(diags).toHaveLength(1);
+      expect(diags[0].kind).toBe("init");
+      warn.mockRestore();
+    });
+
+    test("reports a tag modifier that fails to evaluate", () => {
+      const warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+      initReactivity({
+        declarations: [],
+        tagModifiers: [
+          { tag: "#warrior", target: "$hp", expression: "#x * 2", threshold: 1 },
+        ],
+      });
+
+      setBase("$class", "#warrior:1");
+      computeCascade("$class", undefined, store({ $class: "#warrior:1" }));
+
+      const diags = getReactivityDiagnostics();
+      expect(diags).toHaveLength(1);
+      expect(diags[0].kind).toBe("modifier");
+      expect(diags[0].key).toBe("$hp");
+      expect(diags[0].tag).toBe("#warrior");
+      expect(diags[0].source).toBe("$class");
+      warn.mockRestore();
+    });
+
+    test("keeps cascading other dependents when a declaration fails", () => {
+      const warn = jest.spyOn(console, "warn").mockImplementation(() => {});
+      initReactivity({
+        declarations: [
+          { key: "$bad", expression: "$con * #warrior" },
+          { key: "$good", expression: "$con + 1" },
+        ],
+        tagModifiers: [],
+      });
+
+      const cascade = computeCascade("$con", undefined, store({ $con: "5" }));
+      expect(cascade.find((r) => r.key === "$good")?.value).toBe("6");
+      expect(cascade.find((r) => r.key === "$bad")).toBeUndefined();
+      expect(getReactivityDiagnostics().some((d) => d.key === "$bad")).toBe(true);
+      warn.mockRestore();
+    });
+  });
+
   describe("getCombined / setBase", () => {
     test("returns base value when no mods", () => {
       initReactivity({ declarations: [], tagModifiers: [] });

src/components/journal/VariableView.tsx

@@ -17,6 +17,9 @@ export const VariableView: Component = () => {
 
   const values = createMemo(() => stream.variables);
 
+  /** Runtime engine diagnostics (bad declarations / modifiers). */
+  const diagnostics = createMemo(() => comp.diagnostics());
+
   /** Flat list of all variables */
   const items = createMemo(() => {
     const vars = values();
@@ -32,6 +35,20 @@ export const VariableView: Component = () => {
 
   return (
     <div class="h-full overflow-y-auto bg-gray-50">
+      <Show when={diagnostics().length > 0}>
+        <div class="border-b border-amber-200 bg-amber-50 px-3 py-2">
+          <div class="text-xs font-semibold text-amber-800 mb-1">
+            变量求值有 {diagnostics().length} 个问题
+          </div>
+          <ul class="space-y-1">
+            <For each={diagnostics()}>
+              {(d) => (
+                <li class="text-xs text-amber-700 font-mono break-all">{d.message}</li>
+              )}
+            </For>
+          </ul>
+        </div>
+      </Show>
       <Show
         when={hasAnyData()}
         fallback={

src/components/journal/completions.ts

@@ -30,7 +30,7 @@ import type {
   VarDeclaration,
   TagModifier,
 } from "../../cli/completions/types";
-import { initReactivity, computeInitialValues, rebuildReactivityFromStore } from "./var-reactivity";
+import { initReactivity, computeInitialValues, rebuildReactivityFromStore, getReactivityDiagnostics, onReactivityDiagnostics, type ReactivityDiagnostic } from "./var-reactivity";
 import {
   sendMessage,
   journalStreamState,
@@ -58,6 +58,14 @@ const [completionsState, setCompletionsState] = createSignal<CompletionsState>({
   status: "loading",
 });
 
+// Runtime diagnostics from the variable engine (bad declarations, modifier
+// expressions, circular deps). Bridged into a signal so components can render
+// them; the engine itself stays Solid-free.
+const [reactivityDiagnostics, setReactivityDiagnostics] = createSignal<
+  ReactivityDiagnostic[]
+>(getReactivityDiagnostics());
+onReactivityDiagnostics((list) => setReactivityDiagnostics(list));
+
 // The registry backing the completions. Populated in both CLI and client
 // modes so inline content ids can be resolved at runtime (e.g. spark rolls).
 let activeRegistry: ContentRegistry = { pathIndex: {}, docContent: {} };
@@ -225,13 +233,16 @@ export function ensureCompletions(): Promise<void> {
 export function useJournalCompletions(): {
   state: CompletionsState;
   data: JournalCompletions;
+  /** Reactive accessor for runtime variable-engine diagnostics. */
+  diagnostics: () => ReactivityDiagnostic[];
 } {
   const s = completionsState();
   if (s.status === "loaded") {
-    return { state: s, data: s.data };
+    return { state: s, data: s.data, diagnostics: reactivityDiagnostics };
   }
   return {
     state: s,
+    diagnostics: reactivityDiagnostics,
     data: {
       dice: [],
       links: [],

src/components/journal/index.ts

@@ -60,7 +60,7 @@ export { parseDeclareCsv } from "./declare-parser";
 export type { VarDeclaration, TagModifier } from "./declare-parser";
 export { evaluateExpression, expressionIsTag, exprValueToString } from "./variable-expression";
 export type { EvalContext, EvalResult, ExprValue } from "./variable-expression";
-export { initReactivity, computeCascade, getCombined, getMods, getDeclExpr, setBase, extractDependencies, computeInitialValues } from "./var-reactivity";
+export { initReactivity, computeCascade, getCombined, getMods, getDeclExpr, setBase, extractDependencies, computeInitialValues, getReactivityDiagnostics, clearReactivityDiagnostics, onReactivityDiagnostics } from "./var-reactivity";
-export type { VarReactivityState, VariableStore } from "./var-reactivity";
+export type { VarReactivityState, VariableStore, ReactivityDiagnostic } from "./var-reactivity";
 export { JournalContext, useJournalContext } from "./JournalContext";
 export type { JournalContextValue } from "./JournalContext";

src/components/journal/var-reactivity.ts

@@ -56,6 +56,26 @@ export interface ActiveMod {
   kind: "numeric" | "tagmap";
 }
 
+/**
+ * A problem detected while evaluating declarations or tag modifiers at
+ * runtime. These are benign to the engine (the offending entry is skipped) but
+ * signal an authoring mistake that would otherwise silently produce a wrong
+ * value, so they are collected for surfacing in the UI.
+ */
+export interface ReactivityDiagnostic {
+  kind: "init" | "declaration" | "modifier";
+  /** Human-readable description, already including the offending context. */
+  message: string;
+  /** The variable the diagnostic concerns (e.g. "$hp"). */
+  key?: string;
+  /** The expression that failed to evaluate. */
+  expression?: string;
+  /** For modifiers: the tag whose activation triggered the modifier ("#warrior"). */
+  tag?: string;
+  /** For modifiers: the variable whose tagmap activated the tag ("$class"). */
+  source?: string;
+}
+
 // ---------------------------------------------------------------------------
 // Tagmap helpers
 // ---------------------------------------------------------------------------
@@ -133,6 +153,61 @@ const sourceActivations = new Map<string, Array<{
 /** Set of $vars currently being re-evaluated (cycle guard) */
 const inFlight = new Set<string>();
 
+/** Diagnostics collected since the last init, keyed by a stable id to dedupe. */
+const diagnostics = new Map<string, ReactivityDiagnostic>();
+
+/** Listeners notified whenever the diagnostic set changes. */
+const diagnosticListeners = new Set<(diagnostics: ReactivityDiagnostic[]) => void>();
+
+function errorText(e: unknown): string {
+  return e instanceof Error ? e.message : String(e);
+}
+
+function diagnosticId(d: ReactivityDiagnostic): string {
+  return [d.kind, d.key ?? "", d.expression ?? "", d.source ?? "", d.tag ?? "", d.message].join("\u0000");
+}
+
+function notifyDiagnostics(): void {
+  const list = [...diagnostics.values()];
+  for (const listener of diagnosticListeners) listener(list);
+}
+
+/** Record a diagnostic, dedupe by identity, and notify listeners. */
+function reportDiagnostic(d: ReactivityDiagnostic): void {
+  const id = diagnosticId(d);
+  if (diagnostics.has(id)) return;
+  diagnostics.set(id, d);
+  notifyDiagnostics();
+  console.warn(`[var-reactivity] ${d.message}`);
+}
+
+/**
+ * Diagnostics collected by the engine (bad declarations, modifier expressions,
+ * circular dependencies). Cleared by `initReactivity` so a re-init reports a
+ * fresh set. Repeated failures of the same expression are reported once.
+ */
+export function getReactivityDiagnostics(): ReactivityDiagnostic[] {
+  return [...diagnostics.values()];
+}
+
+/** Remove all collected diagnostics. */
+export function clearReactivityDiagnostics(): void {
+  if (diagnostics.size === 0) return;
+  diagnostics.clear();
+  notifyDiagnostics();
+}
+
+/**
+ * Subscribe to diagnostic changes. The listener receives the current list on
+ * every change. Returns an unsubscribe function.
+ */
+export function onReactivityDiagnostics(
+  listener: (diagnostics: ReactivityDiagnostic[]) => void,
+): () => void {
+  diagnosticListeners.add(listener);
+  return () => diagnosticListeners.delete(listener);
+}
+
 // ---------------------------------------------------------------------------
 // Public API
 // ---------------------------------------------------------------------------
@@ -151,6 +226,7 @@ export function initReactivity(state: VarReactivityState): void {
   numericMods.clear();
   tagMapMods.clear();
   sourceActivations.clear();
+  clearReactivityDiagnostics();
 
   // Index tag modifiers
   for (const tm of state.tagModifiers) {
@@ -176,7 +252,15 @@ export function initReactivity(state: VarReactivityState): void {
     }
   }
 
-  checkCircular();
+  try {
+    checkCircular();
+  } catch (e) {
+    reportDiagnostic({
+      kind: "init",
+      message: `Declarations contain an unresolvable dependency: ${errorText(e)}`,
+    });
+    throw e;
+  }
 }
 
 /** Extract $var names from an expression string. */
@@ -400,8 +484,13 @@ export function computeInitialValues(
       if (!results.some((x) => x.key === key)) {
         results.push({ key, value: combined, base: rawValue });
       }
-    } catch {
+    } catch (e) {
-      // skip failed evaluations at init time
+      reportDiagnostic({
+        kind: "declaration",
+        key,
+        expression: expr,
+        message: `Declaration ${key} failed to evaluate "${expr}": ${errorText(e)}`,
+      });
     }
   }
 
@@ -506,8 +595,17 @@ function applyTagMapActivations(
           } else {
             results.push({ key: mod.target, value: combined, base });
           }
-        } catch {
+        } catch (e) {
-          // skip failed modifier
+          reportDiagnostic({
+            kind: "modifier",
+            key: mod.target,
+            expression: mod.expression,
+            tag,
+            source,
+            message:
+              `Modifier ${tag} → ${mod.target} failed to evaluate ` +
+              `"${mod.expression}" (activated by ${source}): ${errorText(e)}`,
+          });
         }
       } else if (wasActive && !isActive) {
         // Deactivate this modifier
@@ -635,6 +733,14 @@ function reevaluateDependents(
       if (!results.some((x) => x.key === key)) {
         results.push({ key, value: combined, base: rawValue });
       }
+    } catch (e) {
+      // Report the bad declaration but keep evaluating unrelated dependents.
+      reportDiagnostic({
+        kind: "declaration",
+        key,
+        expression: declExprs.get(key),
+        message: `Declaration ${key} failed to re-evaluate "${declExprs.get(key) ?? ""}": ${errorText(e)}`,
+      });
     } finally {
       inFlight.delete(key);
     }

src/components/journal/variable-expression.ts

@@ -17,6 +17,7 @@
  *   - Division by zero
  *   - Unknown functions
  *   - Malformed expressions
+ *   - Malformed numeric literals (e.g. "1.2.3")
  */
 
 import { rollFormula } from "../md-commander/hooks";
@@ -168,6 +169,9 @@ interface Token {
 /** Dice pattern: e.g. "3d6", "2d8kh1", "d20" */
 const DICE_RE = /^\d*d\d+(?:[kdh]\d+)*$/i;
 
+/** Numeric literal: integer or decimal with digits on both sides of the dot. */
+const NUMBER_RE = /^\d+(?:\.\d+)?$/;
+
 /** Single tagmap entry: "#warrior" or "#warrior:1" */
 const TAGMAP_ENTRY_RE = /^#([a-zA-Z_][a-zA-Z0-9_]*)(?::(\d+))?/;
 
@@ -205,6 +209,12 @@ function tokenize(input: string): Token[] {
         tokens.push({ kind: "number", value: String(rollDice(dice)), raw: dice });
         continue;
       }
+      // The scanner above consumes digits and dots greedily, so "1.2.3" and
+      // "1." arrive here as a single chunk. Reject them rather than letting
+      // parseFloat silently truncate to a wrong value.
+      if (!NUMBER_RE.test(num)) {
+        throw new Error(`Invalid number literal: "${num}"`);
+      }
       tokens.push({ kind: "number", value: num, raw: num });
       continue;
     }