📦 NEW: checkAllSettle (#2)

* 📦 NEW: checkAllSettle

* add test

Author: rphlmr

README.md

@@ -89,7 +89,7 @@ Finally, if the condition is a type guard, the parameter you pass will be inferr
 To define policies, you create a policy set using the `definePolicies` function.
 Each policy definition is created using the `definePolicy` function, which takes a policy name and a callback that defines the policy logic (or a boolean value).
 
-> [!IMPORTANT]  
+> [!IMPORTANT]
 > For convenience, the condition can be a boolean value but **you will lose type inference**
 >
 > If you want TS to infer something (not null, union, etc), use a condition function
@@ -393,6 +393,56 @@ if (check(guard.post.policy("post has comments"), post)) {
   console.log("Post has comments");
 }
 ```
+
+### `checkAllSettle`
+Evaluates all the policies with `check` and returns a snapshot with the results.
+
+It's useful to serialize policies.
+
+```ts
+export function checkAllSettle<TPolicies extends PolicyTuple[], TPolicyName extends TPolicies[number][0]["name"]>(
+  policies: TPolicies
+): PoliciesSnapshot<TPolicyName>
+```
+
+Example:
+```ts
+// TLDR
+const snapshot = checkAllSettle([
+  [guard.post.policy("my post"), post],
+  [guard.post.policy("all my published posts"), post],
+]);
+
+// Example
+const PostPolicies = definePolicies((context: Context) => {
+  const myPostPolicy = definePolicy(
+    "my post",
+    (post: Post) => post.userId === context.userId,
+    () => new Error("Not the author")
+  );
+
+  return [
+    myPostPolicy,
+    definePolicy("all published posts or mine", (post: Post) =>
+      or(check(myPostPolicy, post), post.status === "published")
+    ),
+  ];
+});
+
+const guard = {
+  post: PostPolicies(context),
+};
+
+const snapshot = checkAllSettle([
+  [guard.post.policy("my post"), post],
+  [guard.post.policy("all my published posts"), post],
+  ["post has comments", post.comments.length > 0],
+]);
+
+console.log(snapshot); // { "my post": boolean; "all my published posts": boolean; "post has comments": boolean; }
+console.log(snapshot["my post"]) // boolean
+```
+
 ### Condition helpers
 #### `or`
 Logical OR operator for policy conditions.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "comply",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "Comply is a tiny library to help you define policies in your app",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",

src/index.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, expectTypeOf, it } from "vitest";
 import { z } from "zod";
-import { assert, and, check, definePolicies, definePolicy, matchSchema, notNull, or } from ".";
+import { assert, and, check, checkAllSettle, definePolicies, definePolicy, matchSchema, notNull, or } from ".";
 
 describe("Define policy", () => {
   type Post = { userId: string; comments: string[] };
@@ -887,3 +887,63 @@ describe("Logical operators", () => {
     ).toThrowError();
   });
 });
+
+describe("Check all settle", () => {
+  type Context = { userId: string };
+  type Post = { userId: string; comments: string[]; status: "published" | "draft" | "archived" };
+
+  it("should snapshot policies", () => {
+    const PostPolicies = definePolicies((context: Context) => {
+      const myPostPolicy = definePolicy(
+        "my post",
+        (post: Post) => post.userId === context.userId,
+        () => new Error("Not the author")
+      );
+
+      return [
+        myPostPolicy,
+        definePolicy("all my published posts", (post: Post) =>
+          and(check(myPostPolicy, post), post.status === "published")
+        ),
+      ];
+    });
+
+    const guard = {
+      post: PostPolicies({ userId: "1" }),
+    };
+
+    const snapshot = checkAllSettle([
+      [definePolicy("is not null", notNull), "not null"],
+      [definePolicy("is true", true)],
+      ["post has comments", true],
+      ["post has likes", () => true],
+      [guard.post.policy("my post"), { userId: "1", comments: [], status: "published" }],
+      [guard.post.policy("all my published posts"), { userId: "1", comments: [], status: "published" }],
+    ]);
+
+    expect(snapshot).toStrictEqual({
+      "is not null": true,
+      "is true": true,
+      "post has comments": true,
+      "post has likes": true,
+      "my post": true,
+      "all my published posts": true,
+    });
+
+    expectTypeOf(snapshot).toEqualTypeOf<{
+      "is not null": boolean;
+      "is true": boolean;
+      "post has comments": boolean;
+      "post has likes": boolean;
+      "my post": boolean;
+      "all my published posts": boolean;
+    }>();
+
+    /** @ts-expect-error */
+    expectTypeOf(checkAllSettle([[definePolicy("is not null", notNull)]])).toEqualTypeOf<{ [x: string]: boolean }>();
+    /** @ts-expect-error */
+    expectTypeOf(checkAllSettle([[definePolicy("is true", true), "extra arg"]])).toEqualTypeOf<{
+      [x: string]: boolean;
+    }>();
+  });
+});

src/index.ts

@@ -131,7 +131,7 @@ type PolicySetOrFactory<T extends PoliciesOrFactory> = T extends AnyPolicies
     ? (...args: Parameters<T>) => PolicySet<ReturnType<T>>
     : never;
 
-type WithRequiredContext<T> = T extends (arg: infer A) => any ? (unknown extends A ? never : T) : never;
+type WithRequiredArg<T> = T extends (arg: infer A) => any ? (unknown extends A ? never : T) : never;
 
 /**
  * Create a set of policies
@@ -222,7 +222,7 @@ export function definePolicies<T extends AnyPolicies>(policies: T): PolicySet<T>
  * ```
  */
 export function definePolicies<Context, T extends PoliciesOrFactory>(
-  define: WithRequiredContext<(context: Context) => T>
+  define: WithRequiredArg<(context: Context) => T>
 ): (context: Context) => PolicySetOrFactory<T>;
 
 export function definePolicies<Context, T extends PoliciesOrFactory>(defineOrPolicies: T | ((context: Context) => T)) {
@@ -589,6 +589,89 @@ export function check<TPolicyCondition extends PolicyCondition>(
   return typeof policy.condition === "boolean" ? policy.condition : policy.condition(arg);
 }
 
+type PolicyTuple =
+  | readonly [string, PolicyConditionNoArg]
+  | readonly [Policy<string, PolicyConditionNoArg>]
+  | readonly [Policy<string, PolicyConditionWithArg>, any];
+
+type InferPolicyName<TPolicyTuple> = TPolicyTuple extends readonly [infer name, any]
+  ? name extends Policy<infer Name, any>
+    ? Name
+    : name extends string
+      ? name
+      : never
+  : TPolicyTuple extends readonly [Policy<infer Name, any>]
+    ? Name
+    : never;
+
+type PoliciesSnapshot<TPolicyName extends string> = { [K in TPolicyName]: boolean };
+
+/**
+ * Create a snapshot of policies and their evaluation results
+ *
+ * It evaluates all the policies with `check`
+ *
+ * @param policies - A tuple of policies and their arguments (if needed)
+ *
+ * @example
+ * ```ts
+ * // TLDR
+   const snapshot = checkAllSettle([
+    [guard.post.policy("my post"), post],
+    [guard.post.policy("all my published posts"), post],
+    ["post has comments", post.comments.length > 0],
+  ]);
+
+  // returns: { "my post": boolean; "all my published posts": boolean; "post has comments": boolean; }
+
+ * // Example
+  const PostPolicies = definePolicies((context: Context) => {
+    const myPostPolicy = definePolicy(
+      "my post",
+      (post: Post) => post.userId === context.userId,
+      () => new Error("Not the author")
+    );
+
+    return [
+      myPostPolicy,
+      definePolicy("all published posts or mine", (post: Post) =>
+        or(check(myPostPolicy, post), post.status === "published")
+      ),
+    ];
+  });
+
+  const guard = {
+    post: PostPolicies(context),
+  };
+
+  const snapshot = checkAllSettle([
+    [guard.post.policy("my post"), post],
+    [guard.post.policy("all my published posts"), post],
+    ["post has comments", post.comments.length > 0],
+  ]);
+
+  console.log(snapshot); // { "my post": boolean; "all my published posts": boolean; "post has comments": boolean; }
+ * ```
+ */
+export function checkAllSettle<
+  const TPolicies extends readonly PolicyTuple[],
+  TPolicyTuple extends TPolicies[number],
+  TPolicyName extends InferPolicyName<TPolicyTuple>,
+>(policies: TPolicies): PoliciesSnapshot<TPolicyName> {
+  return policies.reduce(
+    (acc, policyTuple) => {
+      const [policyOrName, arg] = policyTuple;
+      const policyName = typeof policyOrName === "string" ? policyOrName : policyOrName.name;
+
+      acc[policyName as TPolicyName] =
+        typeof policyOrName === "string" ? (typeof arg === "function" ? arg() : arg) : policyOrName.check(arg);
+
+      return acc;
+    },
+    {} as PoliciesSnapshot<TPolicyName>
+  );
+}
+
 /* -------------------------------------------------------------------------- */
 /*                                  Helpers;                                  */
 /* -------------------------------------------------------------------------- */