feat(grid): add column formatters

tests/columnFormatter.test.ts

@@ -0,0 +1,66 @@
+import { strict as assert } from "node:assert";
+import test from "node:test";
+import {
+  applyColumnFormatter,
+  buildColumnFormatterKey,
+  normalizeColumnFormatter,
+  type ColumnFormatterConfig,
+} from "../src/lib/columnFormatter.ts";
+
+test("formats unix timestamps in seconds, milliseconds, and auto mode", () => {
+  assert.equal(
+    applyColumnFormatter(1715758200, { kind: "datetime", unit: "seconds" }),
+    new Date(1715758200 * 1000).toLocaleString(),
+  );
+  assert.equal(
+    applyColumnFormatter(1715758200000, { kind: "datetime", unit: "milliseconds" }),
+    new Date(1715758200000).toLocaleString(),
+  );
+  assert.equal(
+    applyColumnFormatter("1715758200", { kind: "datetime", unit: "auto" }),
+    new Date(1715758200 * 1000).toLocaleString(),
+  );
+});
+
+test("extracts simple JSON paths from object and array strings", () => {
+  const payload = JSON.stringify({ user: { name: "Ada" }, items: [{ id: 7 }] });
+
+  assert.equal(applyColumnFormatter(payload, { kind: "json-path", path: "$.user.name" }), "Ada");
+  assert.equal(applyColumnFormatter(payload, { kind: "json-path", path: "$.items[0].id" }), "7");
+  assert.equal(applyColumnFormatter(payload, { kind: "json-path", path: "$.missing" }), "");
+});
+
+test("masks strings while preserving prefix and suffix", () => {
+  assert.equal(applyColumnFormatter("abcdef123456", { kind: "mask", prefix: 3, suffix: 2 }), "abc*******56");
+  assert.equal(applyColumnFormatter("short", { kind: "mask", prefix: 3, suffix: 3 }), "*****");
+});
+
+test("falls back to normal display for nulls and invalid formatter input", () => {
+  assert.equal(applyColumnFormatter(null, { kind: "datetime", unit: "auto" }), "NULL");
+  assert.equal(applyColumnFormatter("not json", { kind: "json-path", path: "$.a" }), "not json");
+  assert.deepEqual(normalizeColumnFormatter({ kind: "datetime", unit: "invalid" }), undefined);
+});
+
+test("normalizes only supported formatter configs", () => {
+  const config: ColumnFormatterConfig = { kind: "mask", prefix: 2, suffix: 4 };
+
+  assert.deepEqual(normalizeColumnFormatter(config), config);
+  assert.deepEqual(normalizeColumnFormatter({ kind: "json-path", path: "$.a[0]" }), {
+    kind: "json-path",
+    path: "$.a[0]",
+  });
+  assert.equal(normalizeColumnFormatter({ kind: "json-path", path: "a.b" }), undefined);
+});
+
+test("builds stable formatter keys for table columns", () => {
+  assert.equal(
+    buildColumnFormatterKey({
+      connectionId: "conn",
+      database: "db",
+      schema: "public",
+      tableName: "users",
+      column: "created_at",
+    }),
+    "conn::db::public::users::created_at",
+  );
+});