feat: add memoize and memoized API (#53)

Author: fabnguess

README.md

@@ -61,6 +61,22 @@ const result = (await RC.write(void 0, writeOpts)).unwrap();
 assert.strictEqual(result, void 0);
 ```
 
+memoize/memoized:
+
+```ts
+import * as RC from "@nodesecure/rc";
+import assert from "node:assert";
+
+const configurationPayload = (
+    await RC.read(void 0, { createMode: "ci" })
+).unwrap()
+
+RC.memoize(configurationPayload, { overwrite: true });
+
+const memoizedPayload = RC.memoized();
+assert.deepEqual(configurationPayload, memoizedPayload);
+```
+
 > 👀 .read and .write return Rust like [Result](https://doc.rust-lang.org/std/result/) object. Under the hood we use [ts-results](https://github.com/vultix/ts-results) to achieve this.
 
 ## API
@@ -125,6 +141,27 @@ export interface writePartialPayload {
 
 export type writeOptions = writeCompletePayload | writePartialPayload;
 ```
+### memoize(payload: Partial<RC>, options: IMemoizeOptions = {}): void
+By default, the memory API overwrites the previous stored payload. When the `OVERWRITE` option is `false`, it merges new properties with existing properties.
+
+```ts
+export interface memoizeOptions {
+  /** * @default true */
+  overwrite?: boolean;
+}
+```
+The `overwrite` option is used to specify whether data should be overwritten or merged.
+
+### memoized(options: IMemoizedOptions): Partial<RC> | null
+This method returns null, when the default value is null, otherwise, it returns the current value of `memoizedValue`.
+
+```ts
+export interface memoizedOptions {
+  /** * @default null */
+  defaultValue: Partial<RC> | null;
+}
+```
+If the `defaultValue` property is at null, then this value will be returned when `memoized` is called.
 
 ### homedir(): string
 

package-lock.json

@@ -45,7 +45,6 @@
     "c8": "^7.12.0",
     "chai": "^4.3.7",
     "eslint": "^8.32.0",
-    "lodash.merge": "^4.6.2",
     "mocha": "^10.2.0",
     "tape": "^5.6.3",
     "ts-node": "^10.9.1",
@@ -57,6 +56,7 @@
     "@nodesecure/js-x-ray": "^6.0.1",
     "@nodesecure/vuln": "^1.7.0",
     "@slimio/config": "^1.2.0",
+    "lodash.merge": "^4.6.2",
     "ts-results": "^3.3.0",
     "tslib": "^2.4.1",
     "type-fest": "^3.5.3"

package.json

@@ -0,0 +1,38 @@
+// Import Third-party Dependencies
+import merge from "lodash.merge";
+
+// Import Internal Dependencies
+import { RC } from "../rc.js";
+
+let memoizedValue: Partial<RC> | null = null;
+
+export interface memoizeOptions {
+  /** * @default true */
+  overwrite?: boolean;
+}
+
+export interface memoizedOptions {
+  /** * @default null */
+  defaultValue?: Partial<RC>;
+}
+
+export function memoize(payload: Partial<RC>, options: memoizeOptions = {}): void {
+  const { overwrite = true } = options;
+  if (memoizedValue === null || overwrite) {
+    memoizedValue = payload;
+  }
+  else {
+    memoizedValue = merge({}, memoizedValue, payload);
+  }
+}
+
+export function memoized(options: memoizedOptions = {}): Partial<RC> | null {
+  const { defaultValue = null } = options;
+
+  return memoizedValue ?? defaultValue;
+}
+
+export function clearMemoized(): void {
+  memoizedValue = null;
+}
+

src/functions/memoize.ts

@@ -1,5 +1,6 @@
 export * from "./functions/read.js";
 export * from "./functions/write.js";
+export * from "./functions/memoize.js";
 export * as CONSTANTS from "./constants.js";
 
 export { RC, JSONSchema, homedir } from "./rc.js";

src/index.ts

@@ -0,0 +1,66 @@
+// Import Third-party Dependencies
+import { expect } from "chai";
+
+// Import Internal Dependencies
+import { generateDefaultRC, RC } from "../src/rc.js";
+import { memoize, memoized, clearMemoized } from "../src/index.js";
+
+let memoizedPayload: Partial<RC> | null = null;
+
+describe("memoize()", () => {
+  beforeEach(() => {
+    memoizedPayload = null;
+  });
+
+  it("should store the payload in memory", () => {
+    const payload = generateDefaultRC();
+    memoize(payload, { overwrite: false });
+
+    memoizedPayload = memoized();
+
+    expect(memoizedPayload).to.deep.equal(payload);
+  });
+
+  it("should overwrite the previous payload if the overwrite option is true", () => {
+    const payload = { version: "2.0.0", i18n: "french", strategy: "yarn" } as any;
+    memoize(payload, { overwrite: true });
+    memoizedPayload = memoized();
+
+    expect(memoizedPayload).to.deep.equal(payload);
+  });
+
+  it("should merge with the previous memoized payload if overwrite option is set to false", () => {
+    const rc = generateDefaultRC();
+    memoize(rc, { overwrite: true });
+
+    const payload = { version: "2.0.0", i18n: "french", strategy: "yarn" } as any;
+    memoize(payload, { overwrite: false });
+    memoizedPayload = memoized();
+
+    expect(memoizedPayload).to.deep.equal({ ...rc, ...payload });
+  });
+});
+
+
+describe("memoized", () => {
+  beforeEach(() => {
+    clearMemoized();
+    memoizedPayload = null;
+  });
+
+
+  it("must return the default value (null)", () => {
+    const result = memoized();
+
+    expect(result).to.deep.equal(memoizedPayload);
+  });
+
+  it("should return previously remembered configuration", () => {
+    const rc = generateDefaultRC();
+
+    memoize(rc, { overwrite: true });
+    memoizedPayload = memoized();
+
+    expect(memoizedPayload).to.deep.equal(rc);
+  });
+});