feat(tree): Update experimental Table Schema APIs to support adding additional properties to Column/Row Schema

examples/utils/import-testing/src/test/importer.spec.ts

@@ -5,7 +5,8 @@
 
 import { strict as assert } from "node:assert";
 
-import { JsonAsTree } from "@fluidframework/tree/alpha";
+// eslint-disable-next-line import/no-internal-modules
+import { JsonAsTree, SchemaFactoryAlpha, TableSchema } from "@fluidframework/tree/internal";
 import type {
 	areSafelyAssignable,
 	requireTrue,
@@ -26,6 +27,57 @@ describe("import tests", () => {
 		assert.equal(r[0], 1);
 	});
 
+	// The TableSchema code is complex and previously had issues where invalid `.d.ts` files were generated by TypeScript.
+	// These tests exist to ensure we don't inadvertently check in changes that regress users' ability to consume that code.
+	it("TableSchema", () => {
+		const schemaFactory = new SchemaFactoryAlpha("com.example");
+
+		class Cell extends schemaFactory.object("table-cell", {
+			value: schemaFactory.string,
+		}) {}
+
+		class ColumnProps extends schemaFactory.object("table-column-props", {
+			label: schemaFactory.optional(schemaFactory.string),
+		}) {}
+		class Column extends TableSchema.createColumn(schemaFactory, ColumnProps) {}
+
+		class RowProps extends schemaFactory.object("table-row-props", {
+			label: schemaFactory.optional(schemaFactory.string),
+		}) {}
+		class Row extends TableSchema.createRow(schemaFactory, Cell, RowProps) {}
+
+		class Table extends TableSchema.createTable(schemaFactory, Cell, Column, Row) {}
+
+		const _table = new Table({
+			columns: [
+				new Column({
+					props: {
+						label: "Column 0",
+					},
+				}),
+				new Column({
+					props: {
+						label: "Column 1",
+					},
+				}),
+			],
+			rows: [
+				new Row({
+					cells: {},
+					props: {
+						label: "Row 0",
+					},
+				}),
+				new Row({
+					cells: {},
+					props: {
+						label: "Row 1",
+					},
+				}),
+			],
+		});
+	});
+
 	// See also the unit tests for JsonAsTree in tree's jsonDomainSchema.spec.ts
 	it("Iterator types", () => {
 		type ImportedArrayNodeIterator = ReturnType<JsonAsTree.Array[typeof Symbol.iterator]>;