feat(link-modules,modules-sdk, utils, types, products) - Remote Link and Link modules (#4695)

What:
- Definition of all Modules links
- `link-modules` package to manage the creation of all pre-defined link or custom ones

```typescript
import { initialize as iniInventory } from "@medusajs/inventory";
import { initialize as iniProduct } from "@medusajs/product";

import {
  initialize as iniLinks,
  runMigrations as migrateLinks
} from "@medusajs/link-modules";

await Promise.all([iniInventory(), iniProduct()]);


await migrateLinks(); // create tables based on previous loaded modules

await iniLinks(); // load link based on previous loaded modules

await iniLinks(undefined, [
  {
    serviceName: "product_custom_translation_service_link",
    isLink: true,
    databaseConfig: {
      tableName: "product_transalations",
    },
    alias: [
      {
        name: "translations",
      },
    ],
    primaryKeys: ["id", "product_id", "translation_id"],
    relationships: [
      {
        serviceName: Modules.PRODUCT,
        primaryKey: "id",
        foreignKey: "product_id",
        alias: "product",
      },
      {
        serviceName: "custom_translation_service",
        primaryKey: "id",
        foreignKey: "translation_id",
        alias: "transalation",
        deleteCascade: true,
      },
    ],
    extends: [
      {
        serviceName: Modules.PRODUCT,
        relationship: {
          serviceName: "product_custom_translation_service_link",
          primaryKey: "product_id",
          foreignKey: "id",
          alias: "translations",
          isList: true,
        },
      },
      {
        serviceName: "custom_translation_service",
        relationship: {
          serviceName: "product_custom_translation_service_link",
          primaryKey: "product_id",
          foreignKey: "id",
          alias: "product_link",
        },
      },
    ],
  },
]); // custom links
```

Remote Link

```typescript
import { RemoteLink, Modules } from "@medusajs/modules-sdk";

// [...] initialize modules and links

const remoteLink = new RemoteLink();

// upsert the relationship
await remoteLink.create({ // one (object) or many (array)
  [Modules.PRODUCT]: {
    variant_id: "var_abc",
  },
  [Modules.INVENTORY]: {
    inventory_item_id: "iitem_abc",
  },
  data: { // optional additional fields
    required_quantity: 5
  }
});

// dismiss (doesn't cascade)
await remoteLink.dismiss({ // one (object) or many (array)
  [Modules.PRODUCT]: {
    variant_id: "var_abc",
  },
  [Modules.INVENTORY]: {
    inventory_item_id: "iitem_abc",
  },
});

// delete
await remoteLink.delete({
  // every key is a module
  [Modules.PRODUCT]: {
    // every key is a linkable field
    variant_id: "var_abc", // single or multiple values
  },
});

// restore
await remoteLink.restore({
  // every key is a module
  [Modules.PRODUCT]: {
    // every key is a linkable field
    variant_id: "var_abc", // single or multiple values
  },
});

```

Co-authored-by: Riqwan Thamir <5105988+riqwan@users.noreply.github.com>

packages/utils/src/modules-sdk/__tests__/load-database-config.spec.ts

@@ -3,15 +3,19 @@ import { loadDatabaseConfig } from "../load-module-database-config"
 describe("loadDatabaseConfig", function () {
   afterEach(() => {
     delete process.env.POSTGRES_URL
+    delete process.env.MEDUSA_POSTGRES_URL
     delete process.env.PRODUCT_POSTGRES_URL
   })
 
-  it("should return the local configuration using the environment variable", function () {
-    process.env.POSTGRES_URL = "postgres://localhost:5432/medusa"
+  it("should return the local configuration using the environment variable respecting their precedence", function () {
+    process.env.MEDUSA_POSTGRES_URL = "postgres://localhost:5432/medusa"
+    process.env.PRODUCT_POSTGRES_URL = "postgres://localhost:5432/product"
+    process.env.POSTGRES_URL = "postgres://localhost:5432/share_db"
+
     let config = loadDatabaseConfig("product")
 
     expect(config).toEqual({
-      clientUrl: process.env.POSTGRES_URL,
+      clientUrl: process.env.PRODUCT_POSTGRES_URL,
       driverOptions: {
         connection: {
           ssl: false,
@@ -21,12 +25,25 @@ describe("loadDatabaseConfig", function () {
       schema: "",
     })
 
-    delete process.env.POSTGRES_URL
-    process.env.PRODUCT_POSTGRES_URL = "postgres://localhost:5432/medusa"
+    delete process.env.PRODUCT_POSTGRES_URL
     config = loadDatabaseConfig("product")
 
     expect(config).toEqual({
-      clientUrl: process.env.PRODUCT_POSTGRES_URL,
+      clientUrl: process.env.MEDUSA_POSTGRES_URL,
+      driverOptions: {
+        connection: {
+          ssl: false,
+        },
+      },
+      debug: false,
+      schema: "",
+    })
+
+    delete process.env.MEDUSA_POSTGRES_URL
+    config = loadDatabaseConfig("product")
+
+    expect(config).toEqual({
+      clientUrl: process.env.POSTGRES_URL,
       driverOptions: {
         connection: {
           ssl: false,
@@ -127,7 +144,7 @@ describe("loadDatabaseConfig", function () {
     }
 
     expect(error.message).toEqual(
-      "No database clientUrl provided. Please provide the clientUrl through the PRODUCT_POSTGRES_URL or POSTGRES_URL environment variable or the options object in the initialize function."
+      "No database clientUrl provided. Please provide the clientUrl through the [MODULE]_POSTGRES_URL, MEDUSA_POSTGRES_URL or POSTGRES_URL environment variable or the options object in the initialize function."
     )
   })
 })