added unique constraint assertion tools

package.json

@@ -1,13 +1,18 @@
 {
   "name": "utility-closet",
-  "version": "0.0.1",
-  "main": "index.js",
+  "version": "0.0.2",
+  "main": "./dist/index.js",
+  "types": "./dist/index.d.ts",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/innocuous-symmetry/utility-closet.git"
+  },
   "scripts": {
     "build": "tsc",
     "test": "vitest"
   },
   "keywords": [],
-  "author": "",
+  "author": "Mikayla Dobson",
   "license": "ISC",
   "dependencies": {
     "csv-parse": "^5.5.5",

pkg/index.ts

@@ -0,0 +1,10 @@
+export * from "./async";
+export * from "./csv";
+export * from "./dom";
+export * from "./logger";
+export * from "./obj";
+export * from "./queue";
+export * from "./time";
+export * from "./types";
+export * from "./unique";
+export * from "./validators";

pkg/unique.ts

@@ -0,0 +1,22 @@
+import { z } from "zod";
+
+export type AssertUniqueType<T extends Record<string, unknown>> = z.ZodEffects<z.ZodArray<z.ZodType<T>>, T[], unknown>;
+
+export function generateUniqueValidator<T extends Record<string, unknown>>(validator: z.ZodType<T>, ...keys: (keyof T)[]) {
+    return validator.array().refine((val) => {
+        for (const key of keys ?? []) {
+            const values = val.map((item) => item[key as keyof T]);
+            return values.length === new Set(values).size;
+        }
+    }, {
+        message: "Encountered duplicate values in unique field"
+    }) satisfies AssertUniqueType<T>;
+}
+
+export function assertUniqueKeys<T extends Record<string, unknown>>(data: T[], validator: z.ZodType<T>, ...keys: (keyof T)[]) {
+    return generateUniqueValidator(validator, ...keys).parse(data) satisfies T[];
+}
+
+export async function assertUniqueKeysAsync<T extends Record<string, unknown>>(data: T[], validator: z.ZodType<T>, ...keys: (keyof T)[]) {
+    return generateUniqueValidator(validator, ...keys).parseAsync(data) satisfies Promise<T[]>;
+}

tests/unique.test.ts

@@ -0,0 +1,50 @@
+import { describe, it, expect } from 'vitest';
+import { z } from 'zod';
+import { assertUniqueKeys } from "../pkg/unique";
+
+describe("assert unique", () => {
+    it("should assert unique keys in a homogenous array", () => {
+        const data = [
+            { id: 1, name: "John" },
+            { id: 2, name: "Doe" },
+            { id: 3, name: "Jane" },
+        ];
+        const validator = z.object({
+            id: z.number(),
+            name: z.string(),
+        });
+
+        expect(
+            () => assertUniqueKeys(data, validator, "id")
+        ).not.toThrow();
+    })
+
+    it("should reject arrays violating unique key constraints", () => {
+        const data = [
+            { id: 1, name: "John" },
+            { id: 1, name: "Doe" },
+            { id: 1, name: "Jane" },
+        ];
+        const validator = z.object({
+            id: z.number(),
+            name: z.string(),
+        });
+
+        expect(
+            () => assertUniqueKeys(data, validator, "id")
+        ).toThrowError("Encountered duplicate values in unique field");
+    })
+
+    it("should only allow record types", () => {
+        const data = [
+            2, 3, 4, 5, "foo", "bar", true
+        ];
+
+        const validator = z.union([z.number(), z.string(), z.boolean()]);
+
+        expect(
+            // @ts-expect-error
+            () => assertUniqueKeys(data, validator)
+        ).toThrow();
+    })
+})