feat(base-formula): add date and coercion functions, wire registry

apps/server/src/core/base/formula/__tests__/eval.spec.ts

@@ -45,8 +45,7 @@ describe("evaluate", () => {
   });
 });
 
-// TODO: unskip after Task 15 wires the function registry with round/concat.
-describe.skip("evaluate with registered functions", () => {
+describe("evaluate with registered functions", () => {
   it("invokes registered functions", () => {
     expect(run('round(1.6)', {})).toBe(2);
     expect(run('concat("a", "b", "c")', {})).toBe("abc");

apps/server/src/core/base/formula/__tests__/typecheck.spec.ts

@@ -1,4 +1,3 @@
-// TODO: unskip after Task 15 lands date functions and populates the registry.
 import { parseRaw, resolve, typecheck, registry } from "@docmost/base-formula/server";
 import type { FormulaAST } from "@docmost/base-formula/server";
 
@@ -9,7 +8,7 @@ const mk = (src: string, propTypes: Record<string, "number" | "string" | "boolea
   return { ast: resolved.ast, typeMap };
 };
 
-describe.skip("typecheck", () => {
+describe("typecheck", () => {
   it("infers number for arithmetic", () => {
     const { ast, typeMap } = mk('prop("Price") * 2', { Price: "number" });
     expect(typecheck(ast, typeMap, registry).resultType).toBe("number");

packages/base-formula/src/functions/date.ts

@@ -0,0 +1,54 @@
+// packages/base-formula/src/functions/date.ts
+import { register } from "./registry";
+import { makeErrorCell } from "../error";
+
+const toDate = (v: unknown): Date | null => {
+  if (v == null) return null;
+  const d = new Date(String(v));
+  return isNaN(d.getTime()) ? null : d;
+};
+
+register({
+  name: "now", arity: { min: 0, max: 0 }, paramTypes: [], returnType: "date",
+  eval: () => new Date().toISOString(),
+  doc: "Current timestamp.", category: "date",
+});
+register({
+  name: "today", arity: { min: 0, max: 0 }, paramTypes: [], returnType: "date",
+  eval: () => {
+    const d = new Date(); d.setUTCHours(0, 0, 0, 0); return d.toISOString();
+  },
+  doc: "Midnight UTC of today.", category: "date",
+});
+register({
+  name: "dateAdd", arity: { min: 3, max: 3 }, paramTypes: ["date", "number", "string"], returnType: "date",
+  eval: ([base, amt, unit]) => {
+    const d = toDate(base);
+    if (!d) return makeErrorCell("DATE_INVALID", "invalid date");
+    const n = Number(amt);
+    const u = String(unit);
+    const r = new Date(d);
+    if (u === "days")    r.setUTCDate(r.getUTCDate() + n);
+    else if (u === "hours")   r.setUTCHours(r.getUTCHours() + n);
+    else if (u === "minutes") r.setUTCMinutes(r.getUTCMinutes() + n);
+    else if (u === "months")  r.setUTCMonth(r.getUTCMonth() + n);
+    else if (u === "years")   r.setUTCFullYear(r.getUTCFullYear() + n);
+    else return makeErrorCell("TYPE_MISMATCH", `unknown unit ${u}`);
+    return r.toISOString();
+  },
+  doc: "Adds a duration to a date. Units: days, hours, minutes, months, years.", category: "date",
+});
+register({
+  name: "dateBetween", arity: { min: 3, max: 3 }, paramTypes: ["date", "date", "string"], returnType: "number",
+  eval: ([a, b, unit]) => {
+    const da = toDate(a), db = toDate(b);
+    if (!da || !db) return makeErrorCell("DATE_INVALID", "invalid date");
+    const ms = db.getTime() - da.getTime();
+    const u = String(unit);
+    if (u === "days")    return Math.floor(ms / 86_400_000);
+    if (u === "hours")   return Math.floor(ms / 3_600_000);
+    if (u === "minutes") return Math.floor(ms / 60_000);
+    return makeErrorCell("TYPE_MISMATCH", `unknown unit ${u}`);
+  },
+  doc: "Difference between two dates in a given unit.", category: "date",
+});

packages/base-formula/src/functions/index.ts

@@ -0,0 +1,8 @@
+// packages/base-formula/src/functions/index.ts
+import "./logic";
+import "./math";
+import "./string";
+import "./date";
+import "./coercion";
+export { registry, register } from "./registry";
+export type { FormulaFn } from "./registry";

packages/base-formula/src/index.server.ts

@@ -7,7 +7,8 @@ export * from "./parser";
 export * from "./resolver";
 export * from "./typecheck";
 export * from "./format";
-export { registry, register } from "./functions/registry";
-export type { FormulaFn } from "./functions/registry";
+import "./functions/index"; // side-effect: populate registry
+export { registry, register } from "./functions/index";
+export type { FormulaFn } from "./functions/index";
 export * from "./graph";
 export * from "./eval";