fix(office): support xlsx date formula helpers

Co-authored-by: Codex (GPT 5.5) <codex@openai.com>

Author: phodal

docs/issues/2026-05-01-office-document-viewer-wasm-reader.md

@@ -128,6 +128,7 @@ Routa 应能在 session canvas 或 artifact tab 中直接预览 Office 文档（
 - XLSX conditional formula evaluation now handles common helper functions used in production rules, including `ISERROR`, `ISNA`, `IF`, `IFERROR`, and `ABS`.
 - XLSX conditional formula evaluation now supports sparse-range `SUMIF`, `SUMIFS`, and `AVERAGEIF` for aggregate threshold rules without dense range materialization.
 - XLSX conditional formula evaluation now handles common text helpers used in production rules, including `SEARCH`, `FIND`, `LEFT`, `RIGHT`, `MID`, `LOWER`, `UPPER`, and `TRIM`.
+- XLSX conditional formula evaluation now handles date-part and parity helpers used in production rules, including `YEAR`, `MONTH`, `DAY`, `WEEKDAY`, `ISODD`, and `ISEVEN`.
 
 ## Codex 技术方案逆向分析
 

src/app/debug/office-wasm-poc/__tests__/spreadsheet-conditional-visuals.test.ts

@@ -860,6 +860,72 @@ describe("spreadsheet conditional visuals", () => {
     expect(visuals.get("4:3")?.background).toBe("#DDD6FE");
   });
 
+  it("evaluates date-part and parity helpers in conditional format formulas", () => {
+    const visuals = buildSpreadsheetConditionalVisuals({
+      conditionalFormattings: [
+        {
+          ranges: ["A2:A5"],
+          rules: [
+            {
+              fillColor: "BAE6FD",
+              formulas: ["=AND(YEAR(A2)=2026,MONTH(A2)=5,DAY(A2)=4)"],
+              type: "expression",
+            },
+          ],
+        },
+        {
+          ranges: ["B2:B5"],
+          rules: [
+            {
+              fillColor: "FDE68A",
+              formulas: ["=WEEKDAY(B2,2)>5"],
+              type: "expression",
+            },
+          ],
+        },
+        {
+          ranges: ["C2:C5"],
+          rules: [
+            {
+              fillColor: "DDD6FE",
+              formulas: ["=ISODD(ROW())"],
+              type: "expression",
+            },
+          ],
+        },
+        {
+          ranges: ["D2:D5"],
+          rules: [
+            {
+              fillColor: "BBF7D0",
+              formulas: ["=ISEVEN(D2)"],
+              type: "expression",
+            },
+          ],
+        },
+      ],
+      rows: [
+        { cells: [{ address: "A2", value: 46146 }, { address: "B2", value: 46144 }, { address: "C2", value: "row2" }, { address: "D2", value: 2 }], index: 2 },
+        { cells: [{ address: "A3", value: 46147 }, { address: "B3", value: 46145 }, { address: "C3", value: "row3" }, { address: "D3", value: 3 }], index: 3 },
+        { cells: [{ address: "A4", value: 46146 }, { address: "B4", value: 46146 }, { address: "C4", value: "row4" }, { address: "D4", value: 4 }], index: 4 },
+        { cells: [{ address: "A5", value: 45782 }, { address: "B5", value: 46150 }, { address: "C5", value: "row5" }, { address: "D5", value: 5 }], index: 5 },
+      ],
+    });
+
+    expect(visuals.get("2:0")?.background).toBe("#BAE6FD");
+    expect(visuals.get("3:0")).toBeUndefined();
+    expect(visuals.get("4:0")?.background).toBe("#BAE6FD");
+    expect(visuals.get("5:0")).toBeUndefined();
+    expect(visuals.get("2:1")?.background).toBe("#FDE68A");
+    expect(visuals.get("3:1")?.background).toBe("#FDE68A");
+    expect(visuals.get("4:1")).toBeUndefined();
+    expect(visuals.get("3:2")?.background).toBe("#DDD6FE");
+    expect(visuals.get("5:2")?.background).toBe("#DDD6FE");
+    expect(visuals.get("2:3")?.background).toBe("#BBF7D0");
+    expect(visuals.get("3:3")).toBeUndefined();
+    expect(visuals.get("4:3")?.background).toBe("#BBF7D0");
+  });
+
   it("resolves table structured references in formula conditional formats", () => {
     const visuals = buildSpreadsheetConditionalVisuals({
       conditionalFormattings: [

src/app/debug/office-wasm-poc/spreadsheet-conditional-formula.ts

@@ -120,6 +120,14 @@ function evaluateFormulaFunction(name: string, args: string[], context: Conditio
   if (normalizedName === "ISNA") {
     return asString(evaluateFormulaValue(args[0] ?? "", context)).trim().toUpperCase() === "#N/A";
   }
+  if (normalizedName === "ISODD") {
+    const value = Number(evaluateFormulaValue(args[0] ?? "", context));
+    return Number.isFinite(value) && Math.abs(Math.floor(value)) % 2 === 1;
+  }
+  if (normalizedName === "ISEVEN") {
+    const value = Number(evaluateFormulaValue(args[0] ?? "", context));
+    return Number.isFinite(value) && Math.abs(Math.floor(value)) % 2 === 0;
+  }
   if (normalizedName === "IF") {
     return valueToBoolean(evaluateFormulaExpression(args[0] ?? "", context))
       ? evaluateFormulaExpression(args[1] ?? "", context)
@@ -226,6 +234,9 @@ function evaluateFormulaFunction(name: string, args: string[], context: Conditio
     }
     return Number.NaN;
   }
+  if (normalizedName === "YEAR" || normalizedName === "MONTH" || normalizedName === "DAY" || normalizedName === "WEEKDAY") {
+    return excelSerialDatePart(Number(evaluateFormulaValue(args[0] ?? "", context)), normalizedName, Number(evaluateFormulaValue(args[1] ?? "1", context)));
+  }
 
   return "";
 }
@@ -618,6 +629,18 @@ function excelSerialDay(year: number, month: number, day: number): number {
   return Math.floor((Date.UTC(year, month - 1, day) - EXCEL_SERIAL_EPOCH_UTC) / DAY_MS);
 }
 
+function excelSerialDatePart(value: number, part: string, weekdayReturnType: number): number {
+  if (!Number.isFinite(value)) return Number.NaN;
+  const date = new Date(EXCEL_SERIAL_EPOCH_UTC + Math.floor(value) * DAY_MS);
+  if (part === "YEAR") return date.getUTCFullYear();
+  if (part === "MONTH") return date.getUTCMonth() + 1;
+  if (part === "DAY") return date.getUTCDate();
+  const weekday = date.getUTCDay();
+  if (weekdayReturnType === 2) return weekday === 0 ? 7 : weekday;
+  if (weekdayReturnType === 3) return weekday === 0 ? 6 : weekday - 1;
+  return weekday + 1;
+}
+
 function parseFunctionCall(value: string): { args: string[]; name: string } | null {
   const nameMatch = value.match(/^([A-Z][A-Z0-9.]*)\(/i);
   if (!nameMatch || !value.endsWith(")")) return null;