feat: Remote Joiner (#4098)

.changeset/afraid-otters-train.md

@@ -0,0 +1,7 @@
+---
+"@medusajs/orchestration": patch
+"@medusajs/types": patch
+"@medusajs/utils": patch
+---
+
+feat: Remote Joiner

packages/orchestration/jest.config.js

@@ -0,0 +1,13 @@
+module.exports = {
+  globals: {
+    "ts-jest": {
+      tsConfig: "tsconfig.json",
+      isolatedModules: false,
+    },
+  },
+  transform: {
+    "^.+\\.[jt]s?$": "ts-jest",
+  },
+  testEnvironment: `node`,
+  moduleFileExtensions: [`js`, `ts`],
+}

packages/orchestration/package.json

@@ -0,0 +1,36 @@
+{
+  "name": "@medusajs/orchestration",
+  "version": "0.0.1",
+  "description": "Medusa utilities to orchestrate modules",
+  "main": "dist/index.js",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/medusajs/medusa",
+    "directory": "packages/orchestration"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "files": [
+    "dist"
+  ],
+  "author": "Medusa",
+  "license": "MIT",
+  "devDependencies": {
+    "@medusajs/types": "^1.8.7",
+    "cross-env": "^5.2.1",
+    "jest": "^25.5.4",
+    "ts-jest": "^25.5.1",
+    "typescript": "^4.4.4"
+  },
+  "dependencies": {
+    "@medusajs/utils": "^1.9.1",
+    "graphql": "^16.6.0"
+  },
+  "scripts": {
+    "prepare": "cross-env NODE_ENV=production yarn run build",
+    "build": "tsc --build",
+    "watch": "tsc --build --watch",
+    "test": "jest"
+  }
+}

packages/orchestration/src/__fixtures__/joiner/data.ts

@@ -0,0 +1,189 @@
+export const remoteJoinerData = {
+  user: [
+    {
+      id: 1,
+      email: "johndoe@example.com",
+      name: "John Doe",
+      fullname: "John Doe full name",
+      products: [
+        {
+          id: 1,
+          product_id: 102,
+        },
+      ],
+      nested: {
+        lala: "lala",
+        multiple: [
+          {
+            abc: 1,
+          },
+          {
+            abc: 2,
+          },
+        ],
+      },
+    },
+    {
+      id: 2,
+      email: "janedoe@example.com",
+      name: "Jane Doe",
+      products: [
+        {
+          id: 2,
+          product_id: [101, 102],
+        },
+      ],
+      nested: {
+        lala: "lele",
+        multiple: [
+          {
+            a: 33,
+          },
+          {
+            a: 44,
+          },
+        ],
+      },
+    },
+    {
+      id: 3,
+      email: "aaa@example.com",
+      name: "aaa bbb",
+      fullname: "3333 Doe full name",
+      nested: {
+        lala: "lolo",
+        multiple: [
+          {
+            a: 555,
+          },
+          {
+            a: 555,
+          },
+        ],
+      },
+    },
+    {
+      id: 4,
+      email: "444444@example.com",
+      name: "a4444 44 44",
+      fullname: "444 Doe full name",
+      products: [
+        {
+          id: 4,
+          product_id: 103,
+        },
+      ],
+      nested: {
+        lala: "lulu",
+        multiple: [
+          {
+            a: 6666,
+          },
+          {
+            a: 7777,
+          },
+        ],
+      },
+    },
+  ],
+  product: {
+    rows: [
+      {
+        id: 101,
+        name: "Product 1",
+        handler: "product-1-handler",
+        user_id: 2,
+      },
+      {
+        id: 102,
+        name: "Product 2",
+        handler: "product-2-handler",
+        user_id: 1,
+      },
+      {
+        id: 103,
+        name: "Product 3",
+        handler: "product-3-handler",
+        user_id: 3,
+      },
+    ],
+    limit: 3,
+    skip: 0,
+  },
+  variant: [
+    {
+      id: 991,
+      name: "Product variant 1",
+      product_id: 101,
+    },
+    {
+      id: 992,
+      name: "Product variant 2",
+      product_id: 101,
+    },
+    {
+      id: 993,
+      name: "Product variant 33",
+      product_id: 103,
+    },
+  ],
+  order_variant: [
+    {
+      order_id: 201,
+      product_id: 101,
+      variant_id: 991,
+      quantity: 1,
+    },
+    {
+      order_id: 201,
+      product_id: 101,
+      variant_id: 992,
+      quantity: 5,
+    },
+    {
+      order_id: 205,
+      product_id: 101,
+      variant_id: 992,
+      quantity: 4,
+    },
+    {
+      order_id: 205,
+      product_id: 103,
+      variant_id: 993,
+      quantity: 1,
+    },
+  ],
+  order: [
+    {
+      id: 201,
+      number: "ORD-001",
+      date: "2023-04-01T12:00:00Z",
+      products: [
+        {
+          product_id: 101,
+          variant_id: 991,
+          quantity: 1,
+        },
+        {
+          product_id: 101,
+          variant_id: 992,
+          quantity: 5,
+        },
+      ],
+      user_id: 4,
+    },
+    {
+      id: 205,
+      number: "ORD-202",
+      date: "2023-04-01T12:00:00Z",
+      products: [
+        {
+          product_id: [101, 103],
+          variant_id: 993,
+          quantity: 4,
+        },
+      ],
+      user_id: 1,
+    },
+  ],
+}

packages/orchestration/src/__mocks__/joiner/mock_data.ts

@@ -0,0 +1,118 @@
+import { JoinerServiceConfig } from "@medusajs/types"
+import { remoteJoinerData } from "./../../__fixtures__/joiner/data"
+
+export const serviceConfigs: JoinerServiceConfig[] = [
+  {
+    serviceName: "User",
+    primaryKeys: ["id"],
+    relationships: [
+      {
+        foreignKey: "products.product_id",
+        serviceName: "Product",
+        primaryKey: "id",
+        alias: "product",
+      },
+    ],
+    extends: [
+      {
+        serviceName: "Variant",
+        resolve: {
+          foreignKey: "user_id",
+          serviceName: "User",
+          primaryKey: "id",
+          alias: "user",
+        },
+      },
+    ],
+  },
+  {
+    serviceName: "Product",
+    primaryKeys: ["id", "sku"],
+    relationships: [
+      {
+        foreignKey: "user_id",
+        serviceName: "User",
+        primaryKey: "id",
+        alias: "user",
+      },
+    ],
+  },
+  {
+    serviceName: "Variant",
+    primaryKeys: ["id"],
+    relationships: [
+      {
+        foreignKey: "product_id",
+        serviceName: "Product",
+        primaryKey: "id",
+        alias: "product",
+      },
+      {
+        foreignKey: "variant_id",
+        primaryKey: "id",
+        serviceName: "Order",
+        alias: "orders",
+        inverse: true, // In an inverted relationship the foreign key is on Order and the primary key is on variant
+      },
+    ],
+  },
+  {
+    serviceName: "Order",
+    primaryKeys: ["id"],
+    relationships: [
+      {
+        foreignKey: "product_id",
+        serviceName: "Product",
+        primaryKey: "id",
+        alias: "product",
+      },
+      {
+        foreignKey: "products.variant_id,product_id",
+        serviceName: "Variant",
+        primaryKey: "id,product_id",
+        alias: "variant",
+      },
+      {
+        foreignKey: "user_id",
+        serviceName: "User",
+        primaryKey: "id",
+        alias: "user",
+      },
+    ],
+  },
+]
+
+export const mockServiceList = (serviceName) => {
+  return jest.fn().mockImplementation((data) => {
+    const src = {
+      userService: remoteJoinerData.user,
+      productService: remoteJoinerData.product,
+      variantService: remoteJoinerData.variant,
+      orderService: remoteJoinerData.order,
+    }
+
+    let resultset = JSON.parse(JSON.stringify(src[serviceName]))
+
+    if (
+      serviceName === "userService" &&
+      !data.fields?.some((field) => field.includes("multiple"))
+    ) {
+      resultset = resultset.map((item) => {
+        delete item.nested.multiple
+        return item
+      })
+    }
+
+    return {
+      data: resultset,
+      path: serviceName === "productService" ? "rows" : undefined,
+    }
+  })
+}
+
+export const serviceMock = {
+  orderService: mockServiceList("orderService"),
+  userService: mockServiceList("userService"),
+  productService: mockServiceList("productService"),
+  variantService: mockServiceList("variantService"),
+}

packages/orchestration/src/__tests__/joiner/graphql-ast.ts

@@ -0,0 +1,239 @@
+import GraphQLParser from "../../joiner/graphql-ast"
+
+describe("RemoteJoiner.parseQuery", () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it("Simple query with fields", async () => {
+    const graphqlQuery = `
+      query {
+        order {
+          id
+          number
+          date
+        }
+      }
+    `
+    const parser = new GraphQLParser(graphqlQuery)
+    const rjQuery = parser.parseQuery()
+
+    expect(rjQuery).toEqual({
+      service: "order",
+      fields: ["id", "number", "date"],
+      expands: [],
+    })
+  })
+
+  it("Simple query with fields and arguments", async () => {
+    const graphqlQuery = `
+      query {
+          order(
+              id: "ord_123",
+              another_arg: 987,
+              complexArg: {
+                  id: "123",
+                  name: "test",
+                  nestedArg: {
+                      nest_id: "abc",
+                      num: 123
+                  }
+              }
+          ) {
+              id
+              number
+              date
+          }
+      }
+    `
+    const parser = new GraphQLParser(graphqlQuery)
+    const rjQuery = parser.parseQuery()
+
+    expect(rjQuery).toEqual({
+      service: "order",
+      fields: ["id", "number", "date"],
+      expands: [],
+      args: [
+        {
+          name: "id",
+          value: "ord_123",
+        },
+        {
+          name: "another_arg",
+          value: 987,
+        },
+        {
+          name: "complexArg",
+          value: {
+            id: "123",
+            name: "test",
+            nestedArg: {
+              nest_id: "abc",
+              num: 123,
+            },
+          },
+        },
+      ],
+    })
+  })
+
+  it("Nested query with fields", async () => {
+    const graphqlQuery = `
+      query {
+        order {
+          id
+          number
+          date
+          products {
+            product_id
+            variant_id
+            order
+            variant {
+              name
+              sku
+            }
+          }
+        }
+      }
+    `
+    const parser = new GraphQLParser(graphqlQuery)
+    const rjQuery = parser.parseQuery()
+
+    expect(rjQuery).toEqual({
+      service: "order",
+      fields: ["id", "number", "date", "products"],
+      expands: [
+        {
+          property: "products",
+          fields: ["product_id", "variant_id", "order", "variant"],
+        },
+        {
+          property: "products.variant",
+          fields: ["name", "sku"],
+        },
+      ],
+    })
+  })
+
+  it("Nested query with fields and arguments", async () => {
+    const graphqlQuery = `
+      query {
+        order (order_id: "ord_123") {
+          id
+          number
+          date
+          products (limit: 10) {
+            product_id
+            variant_id
+            order
+            variant (complexArg: { id: "123", name: "test", nestedArg: { nest_id: "abc", num: 123 } }, region_id: "reg_123") {
+              name
+              sku
+            }
+          }
+        }
+      }
+    `
+    const parser = new GraphQLParser(graphqlQuery)
+    const rjQuery = parser.parseQuery()
+
+    expect(rjQuery).toEqual({
+      service: "order",
+      fields: ["id", "number", "date", "products"],
+      expands: [
+        {
+          property: "products",
+          fields: ["product_id", "variant_id", "order", "variant"],
+          args: [
+            {
+              name: "limit",
+              value: 10,
+            },
+          ],
+        },
+        {
+          property: "products.variant",
+          fields: ["name", "sku"],
+          args: [
+            {
+              name: "complexArg",
+              value: {
+                id: "123",
+                name: "test",
+                nestedArg: {
+                  nest_id: "abc",
+                  num: 123,
+                },
+              },
+            },
+            {
+              name: "region_id",
+              value: "reg_123",
+            },
+          ],
+        },
+      ],
+      args: [
+        {
+          name: "order_id",
+          value: "ord_123",
+        },
+      ],
+    })
+  })
+
+  it("Nested query with fields and arguments using variables", async () => {
+    const graphqlQuery = `
+      query($orderId: ID, $anotherArg: String, $randomVariable: nonValidatedType) {
+        order (order_id: $orderId, anotherArg: $anotherArg) {
+          id
+          number
+          date
+          products (randomValue: $randomVariable) {
+            product_id
+            variant_id
+            order
+          }
+        }
+      }
+    `
+    const parser = new GraphQLParser(graphqlQuery, {
+      orderId: 123,
+      randomVariable: { complex: { num: 12343, str: "str_123" } },
+      anotherArg: "any string",
+    })
+    const rjQuery = parser.parseQuery()
+
+    expect(rjQuery).toEqual({
+      service: "order",
+      fields: ["id", "number", "date", "products"],
+      expands: [
+        {
+          property: "products",
+          fields: ["product_id", "variant_id", "order"],
+          args: [
+            {
+              name: "randomValue",
+              value: {
+                complex: {
+                  num: 12343,
+                  str: "str_123",
+                },
+              },
+            },
+          ],
+        },
+      ],
+      args: [
+        {
+          name: "order_id",
+          value: 123,
+        },
+        {
+          name: "anotherArg",
+          value: "any string",
+        },
+      ],
+    })
+  })
+})

packages/orchestration/src/__tests__/joiner/remote-joiner-data.ts

@@ -0,0 +1,491 @@
+import { MedusaContainer, RemoteExpandProperty } from "@medusajs/types"
+import { lowerCaseFirst, toPascalCase } from "@medusajs/utils"
+import { remoteJoinerData } from "../../__fixtures__/joiner/data"
+import { serviceConfigs, serviceMock } from "../../__mocks__/joiner/mock_data"
+import { RemoteJoiner } from "../../joiner"
+
+const container = {
+  resolve: (serviceName) => {
+    return {
+      list: (...args) => {
+        return serviceMock[serviceName].apply(this, args)
+      },
+      getByVariantId: (options) => {
+        if (serviceName !== "orderService") {
+          return
+        }
+
+        let orderVar = JSON.parse(
+          JSON.stringify(remoteJoinerData.order_variant)
+        )
+
+        if (options.expands?.order) {
+          orderVar = orderVar.map((item) => {
+            item.order = JSON.parse(
+              JSON.stringify(
+                remoteJoinerData.order.find((o) => o.id === item.order_id)
+              )
+            )
+            return item
+          })
+        }
+
+        return {
+          data: orderVar,
+        }
+      },
+    }
+  },
+} as MedusaContainer
+
+const fetchServiceDataCallback = async (
+  expand: RemoteExpandProperty,
+  pkField: string,
+  ids?: (unknown | unknown[])[],
+  relationship?: any
+) => {
+  const serviceConfig = expand.serviceConfig
+  const moduleRegistryName =
+    lowerCaseFirst(serviceConfig.serviceName) + "Service"
+
+  const service = container.resolve(moduleRegistryName)
+  const methodName = relationship?.inverse
+    ? `getBy${toPascalCase(pkField)}`
+    : "list"
+
+  return await service[methodName]({
+    fields: expand.fields,
+    args: expand.args,
+    expands: expand.expands,
+    options: {
+      [pkField]: ids,
+    },
+  })
+}
+
+describe("RemoteJoiner", () => {
+  let joiner: RemoteJoiner
+  beforeAll(() => {
+    joiner = new RemoteJoiner(serviceConfigs, fetchServiceDataCallback)
+  })
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it("Simple query of a service, its id and no fields specified", async () => {
+    const query = {
+      service: "User",
+      args: [
+        {
+          name: "id",
+          value: "1",
+        },
+      ],
+      fields: ["id", "name", "email"],
+    }
+
+    const data = await joiner.query(query)
+
+    expect(data).toEqual([
+      {
+        id: 1,
+        name: "John Doe",
+        email: "johndoe@example.com",
+      },
+      {
+        id: 2,
+        name: "Jane Doe",
+        email: "janedoe@example.com",
+      },
+      {
+        id: 3,
+        name: "aaa bbb",
+        email: "aaa@example.com",
+      },
+      {
+        id: 4,
+        name: "a4444 44 44",
+        email: "444444@example.com",
+      },
+    ])
+  })
+
+  it("Simple query of a service where the returned data contains multiple properties", async () => {
+    const query = RemoteJoiner.parseQuery(`
+      query {
+        product {
+          id
+          name
+        }
+      }
+    `)
+    const data = await joiner.query(query)
+
+    expect(data).toEqual({
+      rows: [
+        {
+          id: 101,
+          name: "Product 1",
+        },
+        {
+          id: 102,
+          name: "Product 2",
+        },
+        {
+          id: 103,
+          name: "Product 3",
+        },
+      ],
+      limit: 3,
+      skip: 0,
+    })
+  })
+
+  it("Query of a service, expanding a property and restricting the fields expanded", async () => {
+    const query = {
+      service: "User",
+      args: [
+        {
+          name: "id",
+          value: "1",
+        },
+      ],
+      fields: ["username", "email", "products"],
+      expands: [
+        {
+          property: "products.product",
+          fields: ["name"],
+        },
+      ],
+    }
+
+    const data = await joiner.query(query)
+
+    expect(data).toEqual([
+      {
+        email: "johndoe@example.com",
+        products: [
+          {
+            id: 1,
+            product_id: 102,
+            product: {
+              name: "Product 2",
+              id: 102,
+            },
+          },
+        ],
+      },
+      {
+        email: "janedoe@example.com",
+        products: [
+          {
+            id: 2,
+            product_id: [101, 102],
+            product: [
+              {
+                name: "Product 1",
+                id: 101,
+              },
+              {
+                name: "Product 2",
+                id: 102,
+              },
+            ],
+          },
+        ],
+      },
+      {
+        email: "aaa@example.com",
+      },
+      {
+        email: "444444@example.com",
+        products: [
+          {
+            id: 4,
+            product_id: 103,
+            product: {
+              name: "Product 3",
+              id: 103,
+            },
+          },
+        ],
+      },
+    ])
+  })
+
+  it("Query a service expanding multiple nested properties", async () => {
+    const query = {
+      service: "Order",
+      fields: ["number", "date", "products"],
+      expands: [
+        {
+          property: "products",
+          fields: ["product"],
+        },
+        {
+          property: "products.product",
+          fields: ["name"],
+        },
+        {
+          property: "user",
+          fields: ["fullname", "email", "products"],
+        },
+        {
+          property: "user.products.product",
+          fields: ["name"],
+        },
+      ],
+      args: [
+        {
+          name: "id",
+          value: "3",
+        },
+      ],
+    }
+
+    const data = await joiner.query(query)
+
+    expect(data).toEqual([
+      {
+        number: "ORD-001",
+        date: "2023-04-01T12:00:00Z",
+        products: [
+          {
+            product_id: 101,
+            product: {
+              name: "Product 1",
+              id: 101,
+            },
+          },
+          {
+            product_id: 101,
+            product: {
+              name: "Product 1",
+              id: 101,
+            },
+          },
+        ],
+        user_id: 4,
+        user: {
+          fullname: "444 Doe full name",
+          email: "444444@example.com",
+          products: [
+            {
+              id: 4,
+              product_id: 103,
+              product: {
+                name: "Product 3",
+                id: 103,
+              },
+            },
+          ],
+          id: 4,
+        },
+      },
+      {
+        number: "ORD-202",
+        date: "2023-04-01T12:00:00Z",
+        products: [
+          {
+            product_id: [101, 103],
+            product: [
+              {
+                name: "Product 1",
+                id: 101,
+              },
+              {
+                name: "Product 3",
+                id: 103,
+              },
+            ],
+          },
+        ],
+        user_id: 1,
+        user: {
+          fullname: "John Doe full name",
+          email: "johndoe@example.com",
+          products: [
+            {
+              id: 1,
+              product_id: 102,
+              product: {
+                name: "Product 2",
+                id: 102,
+              },
+            },
+          ],
+          id: 1,
+        },
+      },
+    ])
+  })
+
+  it("Query a service expanding an inverse relation", async () => {
+    const query = RemoteJoiner.parseQuery(`
+      query {
+        variant {
+          id
+          name
+          orders {
+            order {
+              number
+              products {
+                quantity
+                product {
+                  name
+                }
+                variant {
+                  name
+                }
+              }
+            }
+          }
+        }
+      }
+    `)
+    const data = await joiner.query(query)
+
+    expect(data).toEqual([
+      {
+        id: 991,
+        name: "Product variant 1",
+        orders: {
+          order: {
+            number: "ORD-001",
+            products: [
+              {
+                product_id: 101,
+                variant_id: 991,
+                quantity: 1,
+                product: {
+                  name: "Product 1",
+                  id: 101,
+                },
+                variant: {
+                  name: "Product variant 1",
+                  id: 991,
+                  product_id: 101,
+                },
+              },
+              {
+                product_id: 101,
+                variant_id: 992,
+                quantity: 5,
+                product: {
+                  name: "Product 1",
+                  id: 101,
+                },
+                variant: {
+                  name: "Product variant 2",
+                  id: 992,
+                  product_id: 101,
+                },
+              },
+            ],
+            id: 201,
+          },
+          variant_id: 991,
+          order_id: 201,
+        },
+      },
+      {
+        id: 992,
+        name: "Product variant 2",
+        orders: [
+          {
+            order: {
+              number: "ORD-001",
+              products: [
+                {
+                  product_id: 101,
+                  variant_id: 991,
+                  quantity: 1,
+                  product: {
+                    name: "Product 1",
+                    id: 101,
+                  },
+                  variant: {
+                    name: "Product variant 1",
+                    id: 991,
+                    product_id: 101,
+                  },
+                },
+                {
+                  product_id: 101,
+                  variant_id: 992,
+                  quantity: 5,
+                  product: {
+                    name: "Product 1",
+                    id: 101,
+                  },
+                  variant: {
+                    name: "Product variant 2",
+                    id: 992,
+                    product_id: 101,
+                  },
+                },
+              ],
+              id: 201,
+            },
+            variant_id: 992,
+            order_id: 201,
+          },
+          {
+            order: {
+              number: "ORD-202",
+              products: [
+                {
+                  product_id: [101, 103],
+                  variant_id: 993,
+                  quantity: 4,
+                  product: [
+                    {
+                      name: "Product 1",
+                      id: 101,
+                    },
+                    {
+                      name: "Product 3",
+                      id: 103,
+                    },
+                  ],
+                },
+              ],
+              id: 205,
+            },
+            variant_id: 992,
+            order_id: 205,
+          },
+        ],
+      },
+      {
+        id: 993,
+        name: "Product variant 33",
+        orders: {
+          order: {
+            number: "ORD-202",
+            products: [
+              {
+                product_id: [101, 103],
+                variant_id: 993,
+                quantity: 4,
+                product: [
+                  {
+                    name: "Product 1",
+                    id: 101,
+                  },
+                  {
+                    name: "Product 3",
+                    id: 103,
+                  },
+                ],
+              },
+            ],
+            id: 205,
+          },
+          variant_id: 993,
+          order_id: 205,
+        },
+      },
+    ])
+  })
+})

packages/orchestration/src/__tests__/joiner/remote-joiner.ts

@@ -0,0 +1,287 @@
+import { MedusaContainer, RemoteExpandProperty } from "@medusajs/types"
+import { lowerCaseFirst, toPascalCase } from "@medusajs/utils"
+import { serviceConfigs, serviceMock } from "../../__mocks__/joiner/mock_data"
+import { RemoteJoiner } from "./../../joiner"
+
+const container = {
+  resolve: (serviceName) => {
+    return {
+      list: (...args) => {
+        return serviceMock[serviceName].apply(this, args)
+      },
+    }
+  },
+} as MedusaContainer
+
+const fetchServiceDataCallback = async (
+  expand: RemoteExpandProperty,
+  pkField: string,
+  ids?: (unknown | unknown[])[],
+  relationship?: any
+) => {
+  const serviceConfig = expand.serviceConfig
+  const moduleRegistryName =
+    lowerCaseFirst(serviceConfig.serviceName) + "Service"
+
+  const service = container.resolve(moduleRegistryName)
+  const methodName = relationship?.inverse
+    ? `getBy${toPascalCase(pkField)}`
+    : "list"
+
+  return await service[methodName]({
+    fields: expand.fields,
+    args: expand.args,
+    expands: expand.expands,
+    options: {
+      [pkField]: ids,
+    },
+  })
+}
+
+describe("RemoteJoiner", () => {
+  let joiner: RemoteJoiner
+  beforeAll(() => {
+    joiner = new RemoteJoiner(serviceConfigs, fetchServiceDataCallback)
+  })
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it("Simple query of a service, its id and no fields specified", async () => {
+    const query = {
+      service: "User",
+      args: [
+        {
+          name: "id",
+          value: "1",
+        },
+      ],
+      fields: ["id", "name", "email"],
+    }
+
+    await joiner.query(query)
+
+    expect(serviceMock.userService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.userService).toHaveBeenCalledWith({
+      args: [],
+      fields: ["id", "name", "email"],
+      options: { id: ["1"] },
+    })
+  })
+
+  it("Transforms main service name into PascalCase", async () => {
+    const query = {
+      service: "user",
+      fields: ["id"],
+    }
+
+    await joiner.query(query)
+
+    expect(serviceMock.userService).toHaveBeenCalledTimes(1)
+  })
+
+  it("Simple query of a service, its id and a few fields specified", async () => {
+    const query = {
+      service: "User",
+      args: [
+        {
+          name: "id",
+          value: "1",
+        },
+      ],
+      fields: ["username", "email"],
+    }
+
+    await joiner.query(query)
+
+    expect(serviceMock.userService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.userService).toHaveBeenCalledWith({
+      args: [],
+      fields: ["username", "email"],
+      options: { id: ["1"] },
+    })
+  })
+
+  it("Query of a service, expanding a property and restricting the fields expanded", async () => {
+    const query = {
+      service: "user",
+      fields: ["username", "email", "products"],
+      args: [
+        {
+          name: "id",
+          value: "1",
+        },
+      ],
+      expands: [
+        {
+          property: "products",
+          fields: ["product"],
+        },
+        {
+          property: "products.product",
+          fields: ["name"],
+        },
+      ],
+    }
+
+    await joiner.query(query)
+
+    expect(serviceMock.userService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.userService).toHaveBeenCalledWith({
+      args: [],
+      fields: ["username", "email", "products"],
+      expands: {
+        products: {
+          args: undefined,
+          fields: ["product_id"],
+        },
+      },
+      options: { id: ["1"] },
+    })
+
+    expect(serviceMock.productService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.productService).toHaveBeenCalledWith({
+      fields: ["name", "id"],
+      options: { id: expect.arrayContaining([101, 102, 103]) },
+    })
+  })
+
+  it("Query a service using more than 1 argument, expanding a property with another argument", async () => {
+    const query = {
+      service: "User",
+      args: [
+        {
+          name: "id",
+          value: "1",
+        },
+        {
+          name: "role",
+          value: "admin",
+        },
+      ],
+      fields: ["username", "email", "products"],
+      expands: [
+        {
+          property: "products",
+          fields: ["product"],
+        },
+        {
+          property: "products.product",
+          fields: ["name"],
+          args: [
+            {
+              name: "limit",
+              value: "5",
+            },
+          ],
+        },
+      ],
+    }
+
+    await joiner.query(query)
+
+    expect(serviceMock.userService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.userService).toHaveBeenCalledWith({
+      args: [
+        {
+          name: "role",
+          value: "admin",
+        },
+      ],
+      fields: ["username", "email", "products"],
+      expands: {
+        products: {
+          args: undefined,
+          fields: ["product_id"],
+        },
+      },
+      options: { id: ["1"] },
+    })
+
+    expect(serviceMock.productService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.productService).toHaveBeenCalledWith({
+      fields: ["name", "id"],
+      options: { id: expect.arrayContaining([101, 102, 103]) },
+      args: [
+        {
+          name: "limit",
+          value: "5",
+        },
+      ],
+    })
+  })
+
+  it("Query a service expanding multiple nested properties", async () => {
+    const query = {
+      service: "Order",
+      fields: ["number", "date", "products"],
+      expands: [
+        {
+          property: "products",
+          fields: ["product"],
+        },
+        {
+          property: "products.product",
+          fields: ["handler"],
+        },
+        {
+          property: "user",
+          fields: ["fullname", "email", "products"],
+        },
+        {
+          property: "user.products",
+          fields: ["product"],
+        },
+        {
+          property: "user.products.product",
+          fields: ["name"],
+        },
+      ],
+      args: [
+        {
+          name: "id",
+          value: "3",
+        },
+      ],
+    }
+
+    await joiner.query(query)
+
+    expect(serviceMock.orderService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.orderService).toHaveBeenCalledWith({
+      args: [],
+      fields: ["number", "date", "products", "user_id"],
+      expands: {
+        products: {
+          args: undefined,
+          fields: ["product_id"],
+        },
+      },
+      options: { id: ["3"] },
+    })
+
+    expect(serviceMock.userService).toHaveBeenCalledTimes(1)
+    expect(serviceMock.userService).toHaveBeenCalledWith({
+      fields: ["fullname", "email", "products", "id"],
+      args: undefined,
+      expands: {
+        products: {
+          args: undefined,
+          fields: ["product_id"],
+        },
+      },
+      options: { id: [4, 1] },
+    })
+
+    expect(serviceMock.productService).toHaveBeenCalledTimes(2)
+    expect(serviceMock.productService).toHaveBeenNthCalledWith(1, {
+      fields: ["name", "id"],
+      options: { id: expect.arrayContaining([103, 102]) },
+    })
+
+    expect(serviceMock.productService).toHaveBeenNthCalledWith(2, {
+      fields: ["handler", "id"],
+      options: { id: expect.arrayContaining([101, 103]) },
+    })
+  })
+})

packages/orchestration/src/index.ts

@@ -0,0 +1 @@
+export * from "./joiner"

packages/orchestration/src/joiner/graphql-ast.ts

@@ -0,0 +1,154 @@
+import { RemoteJoinerQuery } from "@medusajs/types"
+import {
+  ArgumentNode,
+  DocumentNode,
+  FieldNode,
+  Kind,
+  OperationDefinitionNode,
+  SelectionSetNode,
+  ValueNode,
+  parse,
+} from "graphql"
+
+interface Argument {
+  name: string
+  value?: unknown
+}
+
+interface Entity {
+  property: string
+  fields: string[]
+  args?: Argument[]
+}
+
+class GraphQLParser {
+  private ast: DocumentNode
+
+  constructor(input: string, private variables?: { [key: string]: unknown }) {
+    this.ast = parse(input)
+    this.variables = variables || {}
+  }
+
+  private parseValueNode(valueNode: ValueNode): unknown {
+    switch (valueNode.kind) {
+      case Kind.VARIABLE:
+        const variableName = valueNode.name.value
+        return this.variables ? this.variables[variableName] : undefined
+      case Kind.INT:
+        return parseInt(valueNode.value, 10)
+      case Kind.FLOAT:
+        return parseFloat(valueNode.value)
+      case Kind.BOOLEAN:
+        return Boolean(valueNode.value)
+      case Kind.STRING:
+      case Kind.ENUM:
+        return valueNode.value
+      case Kind.NULL:
+        return null
+      case Kind.LIST:
+        return valueNode.values.map((v) => this.parseValueNode(v))
+      case Kind.OBJECT:
+        let obj = {}
+        for (const field of valueNode.fields) {
+          obj[field.name.value] = this.parseValueNode(field.value)
+        }
+        return obj
+      default:
+        return undefined
+    }
+  }
+
+  private parseArguments(
+    args: readonly ArgumentNode[]
+  ): Argument[] | undefined {
+    if (!args.length) {
+      return
+    }
+
+    return args.map((arg) => {
+      const value = this.parseValueNode(arg.value)
+
+      return {
+        name: arg.name.value,
+        value: value,
+      }
+    })
+  }
+
+  private extractEntities(
+    node: SelectionSetNode,
+    parentName = "",
+    mainService = ""
+  ): Entity[] {
+    const entities: Entity[] = []
+
+    node.selections.forEach((selection) => {
+      if (selection.kind === "Field") {
+        const fieldNode = selection as FieldNode
+
+        if (fieldNode.selectionSet) {
+          const entityName = parentName
+            ? `${parentName}.${fieldNode.name.value}`
+            : fieldNode.name.value
+
+          const nestedEntity: Entity = {
+            property: entityName.replace(`${mainService}.`, ""),
+            fields: fieldNode.selectionSet.selections.map(
+              (field) => (field as FieldNode).name.value
+            ),
+            args: this.parseArguments(fieldNode.arguments!),
+          }
+
+          entities.push(nestedEntity)
+          entities.push(
+            ...this.extractEntities(
+              fieldNode.selectionSet,
+              entityName,
+              mainService
+            )
+          )
+        }
+      }
+    })
+
+    return entities
+  }
+
+  public parseQuery(): RemoteJoinerQuery {
+    const queryDefinition = this.ast.definitions.find(
+      (definition) => definition.kind === "OperationDefinition"
+    ) as OperationDefinitionNode
+
+    if (!queryDefinition) {
+      throw new Error("No query found")
+    }
+
+    const rootFieldNode = queryDefinition.selectionSet
+      .selections[0] as FieldNode
+
+    const remoteJoinConfig: RemoteJoinerQuery = {
+      service: rootFieldNode.name.value,
+      fields: [],
+      expands: [],
+    }
+
+    if (rootFieldNode.arguments) {
+      remoteJoinConfig.args = this.parseArguments(rootFieldNode.arguments)
+    }
+
+    if (rootFieldNode.selectionSet) {
+      remoteJoinConfig.fields = rootFieldNode.selectionSet.selections.map(
+        (field) => (field as FieldNode).name.value
+      )
+      remoteJoinConfig.expands = this.extractEntities(
+        rootFieldNode.selectionSet,
+        rootFieldNode.name.value,
+        rootFieldNode.name.value
+      )
+    }
+
+    return remoteJoinConfig
+  }
+}
+
+export default GraphQLParser

packages/orchestration/src/joiner/index.ts

@@ -0,0 +1 @@
+export * from "./remote-joiner"

packages/orchestration/src/joiner/remote-joiner.ts

@@ -0,0 +1,575 @@
+import {
+  JoinerRelationship,
+  JoinerServiceConfig,
+  RemoteExpandProperty,
+  RemoteJoinerQuery,
+  RemoteNestedExpands,
+} from "@medusajs/types"
+import { isDefined, toPascalCase } from "@medusajs/utils"
+import GraphQLParser from "./graphql-ast"
+
+const BASE_PATH = "_root"
+export class RemoteJoiner {
+  private serviceConfigs: JoinerServiceConfig[]
+  private serviceConfigCache: Map<string, JoinerServiceConfig> = new Map()
+
+  private static filterFields(
+    data: any,
+    fields: string[],
+    expands?: RemoteNestedExpands
+  ): Record<string, unknown> {
+    if (!fields) {
+      return data
+    }
+
+    const filteredData = fields.reduce((acc: any, field: string) => {
+      acc[field] = data?.[field]
+      return acc
+    }, {})
+
+    if (expands) {
+      for (const key in expands) {
+        const expand = expands[key]
+        if (expand) {
+          if (Array.isArray(data[key])) {
+            filteredData[key] = data[key].map((item: any) =>
+              RemoteJoiner.filterFields(item, expand.fields, expand.expands)
+            )
+          } else {
+            filteredData[key] = RemoteJoiner.filterFields(
+              data[key],
+              expand.fields,
+              expand.expands
+            )
+          }
+        }
+      }
+    }
+
+    return filteredData
+  }
+
+  private static getNestedItems(items: any[], property: string): any[] {
+    return items
+      .flatMap((item) => item[property])
+      .filter((item) => item !== undefined)
+  }
+
+  private static createRelatedDataMap(
+    relatedDataArray: any[],
+    joinFields: string[]
+  ): Map<string, any> {
+    return relatedDataArray.reduce((acc, data) => {
+      const joinValues = joinFields.map((field) => data[field])
+      const key = joinValues.length === 1 ? joinValues[0] : joinValues.join(",")
+
+      let isArray = Array.isArray(acc[key])
+      if (isDefined(acc[key]) && !isArray) {
+        acc[key] = [acc[key]]
+        isArray = true
+      }
+
+      if (isArray) {
+        acc[key].push(data)
+      } else {
+        acc[key] = data
+      }
+      return acc
+    }, {})
+  }
+
+  static parseQuery(graphqlQuery: string, variables?: any): RemoteJoinerQuery {
+    const parser = new GraphQLParser(graphqlQuery, variables)
+    return parser.parseQuery()
+  }
+
+  constructor(
+    serviceConfigs: JoinerServiceConfig[],
+    private remoteFetchData: (
+      expand: RemoteExpandProperty,
+      pkField: string,
+      ids?: (unknown | unknown[])[],
+      relationship?: any
+    ) => Promise<{
+      data: unknown[] | { [path: string]: unknown[] }
+      path?: string
+    }>
+  ) {
+    this.serviceConfigs = this.buildReferences(serviceConfigs)
+  }
+
+  private buildReferences(serviceConfigs: JoinerServiceConfig[]) {
+    const expandedRelationships: Map<string, JoinerRelationship[]> = new Map()
+    for (const service of serviceConfigs) {
+      // self-reference
+      const propName = service.serviceName.toLowerCase()
+      if (!service.relationships) {
+        service.relationships = []
+      }
+
+      service.relationships?.push({
+        alias: propName,
+        foreignKey: propName + "_id",
+        primaryKey: "id",
+        serviceName: service.serviceName,
+      })
+
+      this.serviceConfigCache.set(service.serviceName, service)
+
+      if (!service.extends) {
+        continue
+      }
+
+      for (const extend of service.extends) {
+        if (!expandedRelationships.has(extend.serviceName)) {
+          expandedRelationships.set(extend.serviceName, [])
+        }
+
+        expandedRelationships.get(extend.serviceName)!.push(extend.resolve)
+      }
+    }
+
+    for (const [serviceName, relationships] of expandedRelationships) {
+      if (!this.serviceConfigCache.has(serviceName)) {
+        throw new Error(`Service ${serviceName} not found`)
+      }
+
+      const service = this.serviceConfigCache.get(serviceName)
+      service!.relationships?.push(...relationships)
+    }
+
+    return serviceConfigs
+  }
+
+  private findServiceConfig(
+    serviceName: string
+  ): JoinerServiceConfig | undefined {
+    if (!this.serviceConfigCache.has(serviceName)) {
+      const config = this.serviceConfigs.find(
+        (config) => config.serviceName === serviceName
+      )
+      this.serviceConfigCache.set(serviceName, config!)
+    }
+    return this.serviceConfigCache.get(serviceName)
+  }
+
+  private async fetchData(
+    expand: RemoteExpandProperty,
+    pkField: string,
+    ids?: (unknown | unknown[])[],
+    relationship?: any
+  ): Promise<{
+    data: unknown[] | { [path: string]: unknown[] }
+    path?: string
+  }> {
+    let uniqueIds = Array.isArray(ids) ? ids : ids ? [ids] : undefined
+
+    if (uniqueIds) {
+      const isCompositeKey = Array.isArray(uniqueIds[0])
+      if (isCompositeKey) {
+        const seen = new Set()
+        uniqueIds = uniqueIds.filter((idArray) => {
+          const key = JSON.stringify(idArray)
+          const isNew = !seen.has(key)
+          seen.add(key)
+          return isNew
+        })
+      } else {
+        uniqueIds = Array.from(new Set(uniqueIds.flat()))
+      }
+    }
+
+    if (relationship) {
+      pkField = relationship.inverse
+        ? relationship.foreignKey.split(".").pop()!
+        : relationship.primaryKey
+    }
+
+    const response = await this.remoteFetchData(
+      expand,
+      pkField,
+      uniqueIds,
+      relationship
+    )
+    const isObj = isDefined(response.path)
+    const resData = isObj ? response.data[response.path!] : response.data
+
+    const filteredDataArray = resData.map((data: any) =>
+      RemoteJoiner.filterFields(data, expand.fields, expand.expands)
+    )
+
+    if (isObj) {
+      response.data[response.path!] = filteredDataArray
+    } else {
+      response.data = filteredDataArray
+    }
+
+    return response
+  }
+
+  private async handleExpands(
+    items: any[],
+    query: RemoteJoinerQuery,
+    parsedExpands: Map<string, RemoteExpandProperty>
+  ): Promise<void> {
+    if (!parsedExpands) {
+      return
+    }
+
+    const stack: [
+      any[],
+      RemoteJoinerQuery,
+      Map<string, RemoteExpandProperty>,
+      string,
+      Set<string>
+    ][] = [[items, query, parsedExpands, "", new Set()]]
+
+    while (stack.length > 0) {
+      const [
+        currentItems,
+        currentQuery,
+        currentParsedExpands,
+        basePath,
+        resolvedPaths,
+      ] = stack.pop()!
+
+      for (const [expandedPath, expand] of currentParsedExpands.entries()) {
+        const isImmediateChildPath =
+          expandedPath.startsWith(basePath) &&
+          expandedPath.split(".").length === basePath.split(".").length + 1
+
+        if (!isImmediateChildPath || resolvedPaths.has(expandedPath)) {
+          continue
+        }
+
+        resolvedPaths.add(expandedPath)
+
+        const property = expand.property || ""
+        const parentServiceConfig = this.findServiceConfig(currentQuery.service)
+
+        await this.expandProperty(currentItems, parentServiceConfig!, expand)
+
+        const relationship = parentServiceConfig?.relationships?.find(
+          (relation) => relation.alias === property
+        )
+
+        const nestedItems = RemoteJoiner.getNestedItems(currentItems, property)
+
+        if (nestedItems.length > 0) {
+          const nextProp = relationship
+            ? {
+                ...currentQuery,
+                service: relationship.serviceName,
+              }
+            : currentQuery
+
+          stack.push([
+            nestedItems,
+            nextProp,
+            currentParsedExpands,
+            expandedPath,
+            new Set(),
+          ])
+        }
+      }
+    }
+  }
+
+  private async expandProperty(
+    items: any[],
+    parentServiceConfig: JoinerServiceConfig,
+    expand?: RemoteExpandProperty
+  ): Promise<void> {
+    if (!expand) {
+      return
+    }
+
+    const relationship = parentServiceConfig?.relationships?.find(
+      (relation) => relation.alias === expand.property
+    )
+
+    if (relationship) {
+      await this.expandRelationshipProperty(items, expand, relationship)
+    }
+  }
+
+  private async expandRelationshipProperty(
+    items: any[],
+    expand: RemoteExpandProperty,
+    relationship: JoinerRelationship
+  ): Promise<void> {
+    const field = relationship.inverse
+      ? relationship.primaryKey
+      : relationship.foreignKey.split(".").pop()!
+    const fieldsArray = field.split(",")
+
+    const idsToFetch: any[] = []
+
+    items.forEach((item) => {
+      const values = fieldsArray
+        .map((field) => item[field])
+        .filter((value) => value !== undefined)
+
+      if (values.length === fieldsArray.length && !item[relationship.alias]) {
+        if (fieldsArray.length === 1) {
+          if (!idsToFetch.includes(values[0])) {
+            idsToFetch.push(values[0])
+          }
+        } else {
+          // composite key
+          const valuesString = values.join(",")
+
+          if (!idsToFetch.some((id) => id.join(",") === valuesString)) {
+            idsToFetch.push(values)
+          }
+        }
+      }
+    })
+
+    if (idsToFetch.length === 0) {
+      return
+    }
+
+    const relatedDataArray = await this.fetchData(
+      expand,
+      field,
+      idsToFetch,
+      relationship
+    )
+
+    const joinFields = relationship.inverse
+      ? relationship.foreignKey.split(",")
+      : relationship.primaryKey.split(",")
+
+    const relData = relatedDataArray.path
+      ? relatedDataArray.data[relatedDataArray.path!]
+      : relatedDataArray.data
+
+    const relatedDataMap = RemoteJoiner.createRelatedDataMap(
+      relData,
+      joinFields
+    )
+
+    items.forEach((item) => {
+      if (!item[relationship.alias]) {
+        const itemKey = fieldsArray.map((field) => item[field]).join(",")
+
+        if (Array.isArray(item[field])) {
+          item[relationship.alias] = item[field]
+            .map((id) => relatedDataMap[id])
+            .filter((relatedItem) => relatedItem !== undefined)
+        } else {
+          item[relationship.alias] = relatedDataMap[itemKey]
+        }
+      }
+    })
+  }
+
+  private parseExpands(
+    initialService: RemoteExpandProperty,
+    query: RemoteJoinerQuery,
+    serviceConfig: JoinerServiceConfig,
+    expands: RemoteJoinerQuery["expands"]
+  ): Map<string, RemoteExpandProperty> {
+    const parsedExpands = this.parseProperties(
+      initialService,
+      query,
+      serviceConfig,
+      expands
+    )
+
+    const groupedExpands = this.groupExpands(parsedExpands)
+
+    return groupedExpands
+  }
+
+  private parseProperties(
+    initialService: RemoteExpandProperty,
+    query: RemoteJoinerQuery,
+    serviceConfig: JoinerServiceConfig,
+    expands: RemoteJoinerQuery["expands"]
+  ): Map<string, RemoteExpandProperty> {
+    const parsedExpands = new Map<string, any>()
+    parsedExpands.set(BASE_PATH, initialService)
+
+    for (const expand of expands || []) {
+      const properties = expand.property.split(".")
+      let currentServiceConfig = serviceConfig as any
+      const currentPath: string[] = []
+
+      for (const prop of properties) {
+        const fullPath = [BASE_PATH, ...currentPath, prop].join(".")
+        const relationship = currentServiceConfig.relationships.find(
+          (relation) => relation.alias === prop
+        )
+
+        let fields: string[] | undefined =
+          fullPath === BASE_PATH + "." + expand.property
+            ? expand.fields
+            : undefined
+        const args =
+          fullPath === BASE_PATH + "." + expand.property
+            ? expand.args
+            : undefined
+
+        if (relationship) {
+          const parentExpand =
+            parsedExpands.get([BASE_PATH, ...currentPath].join(".")) || query
+
+          if (parentExpand) {
+            if (parentExpand.fields) {
+              const relField = relationship.inverse
+                ? relationship.primaryKey
+                : relationship.foreignKey.split(".").pop()!
+
+              parentExpand.fields = parentExpand.fields
+                .concat(relField.split(","))
+                .filter((field) => field !== relationship.alias)
+
+              parentExpand.fields = [...new Set(parentExpand.fields)]
+            }
+
+            if (fields) {
+              const relField = relationship.inverse
+                ? relationship.foreignKey.split(".").pop()!
+                : relationship.primaryKey
+              fields = fields.concat(relField.split(","))
+
+              fields = [...new Set(fields)]
+            }
+          }
+
+          currentServiceConfig = this.findServiceConfig(
+            relationship.serviceName
+          )
+
+          if (!currentServiceConfig) {
+            throw new Error(
+              `Target service not found: ${relationship.serviceName}`
+            )
+          }
+        }
+
+        if (!parsedExpands.has(fullPath)) {
+          parsedExpands.set(fullPath, {
+            property: prop,
+            serviceConfig: currentServiceConfig,
+            fields,
+            args,
+          })
+        }
+
+        currentPath.push(prop)
+      }
+    }
+
+    return parsedExpands
+  }
+
+  private groupExpands(
+    parsedExpands: Map<string, RemoteExpandProperty>
+  ): Map<string, RemoteExpandProperty> {
+    const sortedParsedExpands = new Map(
+      Array.from(parsedExpands.entries()).sort()
+    )
+
+    const mergedExpands = new Map<string, RemoteExpandProperty>(
+      sortedParsedExpands
+    )
+    const mergedPaths = new Map<string, string>()
+
+    let lastServiceName = ""
+
+    for (const [path, expand] of sortedParsedExpands.entries()) {
+      const currentServiceName = expand.serviceConfig.serviceName
+
+      let parentPath = path.split(".").slice(0, -1).join(".")
+
+      // Check if the parentPath was merged before
+      while (mergedPaths.has(parentPath)) {
+        parentPath = mergedPaths.get(parentPath)!
+      }
+
+      const canMerge = currentServiceName === lastServiceName
+
+      if (mergedExpands.has(parentPath) && canMerge) {
+        const parentExpand = mergedExpands.get(parentPath)!
+
+        if (parentExpand.serviceConfig.serviceName === currentServiceName) {
+          const nestedKeys = path.split(".").slice(parentPath.split(".").length)
+          let targetExpand: any = parentExpand
+
+          for (let key of nestedKeys) {
+            if (!targetExpand.expands) {
+              targetExpand.expands = {}
+            }
+            if (!targetExpand.expands[key]) {
+              targetExpand.expands[key] = {} as any
+            }
+            targetExpand = targetExpand.expands[key]
+          }
+
+          targetExpand.fields = expand.fields
+          targetExpand.args = expand.args
+          mergedPaths.set(path, parentPath)
+        }
+      } else {
+        lastServiceName = currentServiceName
+      }
+    }
+
+    return mergedExpands
+  }
+
+  async query(queryObj: RemoteJoinerQuery): Promise<any> {
+    queryObj.service = toPascalCase(queryObj.service)
+    const serviceConfig = this.findServiceConfig(queryObj.service)
+
+    if (!serviceConfig) {
+      throw new Error(`Service not found: ${queryObj.service}`)
+    }
+
+    let pkName = serviceConfig.primaryKeys[0]
+    const primaryKeyArg = queryObj.args?.find((arg) => {
+      const inc = serviceConfig.primaryKeys.includes(arg.name)
+      if (inc) {
+        pkName = arg.name
+      }
+      return inc
+    })
+    const otherArgs = queryObj.args?.filter(
+      (arg) => !serviceConfig.primaryKeys.includes(arg.name)
+    )
+
+    const parsedExpands = this.parseExpands(
+      {
+        property: "",
+        serviceConfig: serviceConfig,
+        fields: queryObj.fields,
+        args: otherArgs,
+      },
+      queryObj,
+      serviceConfig,
+      queryObj.expands!
+    )
+
+    const root = parsedExpands.get(BASE_PATH)!
+
+    const response = await this.fetchData(
+      root,
+      pkName,
+      primaryKeyArg?.value,
+      undefined
+    )
+
+    const data = response.path ? response.data[response.path!] : response.data
+
+    await this.handleExpands(
+      Array.isArray(data) ? data : [data],
+      queryObj,
+      parsedExpands
+    )
+
+    return response.data
+  }
+}

packages/orchestration/tsconfig.json

@@ -0,0 +1,29 @@
+{
+  "compilerOptions": {
+    "lib": ["es5", "es6", "es2019"],
+    "target": "es5",
+    "outDir": "./dist",
+    "esModuleInterop": true,
+    "declaration": true,
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "emitDecoratorMetadata": true,
+    "experimentalDecorators": true,
+    "sourceMap": true,
+    "noImplicitReturns": true,
+    "strictNullChecks": true,
+    "strictFunctionTypes": true,
+    "noImplicitThis": true,
+    "allowJs": true,
+    "skipLibCheck": true,
+    "downlevelIteration": true
+  },
+  "include": ["src"],
+  "exclude": [
+    "dist",
+    "./src/**/__tests__",
+    "./src/**/__mocks__",
+    "./src/**/__fixtures__",
+    "node_modules"
+  ]
+}

packages/types/src/index.ts

@@ -3,6 +3,7 @@ export * from "./cache"
 export * from "./common"
 export * from "./event-bus"
 export * from "./inventory"
+export * from "./joiner"
 export * from "./modules-sdk"
 export * from "./product"
 export * from "./product-category"

packages/types/src/joiner/index.ts

@@ -0,0 +1,51 @@
+export type JoinerRelationship = {
+  alias: string
+  foreignKey: string
+  primaryKey: string
+  serviceName: string
+  inverse?: boolean // In an inverted relationship the foreign key is on the other service and the primary key is on the current service
+}
+
+export interface JoinerServiceConfig {
+  serviceName: string
+  primaryKeys: string[]
+  relationships?: JoinerRelationship[]
+  extends?: {
+    serviceName: string
+    resolve: JoinerRelationship
+  }[]
+}
+
+export interface JoinerArgument {
+  name: string
+  value?: any
+  field?: string
+}
+
+export interface RemoteJoinerQuery {
+  service: string
+  expands?: Array<{
+    property: string
+    fields: string[]
+    args?: JoinerArgument[]
+    relationships?: JoinerRelationship[]
+  }>
+  fields: string[]
+  args?: JoinerArgument[]
+}
+
+export interface RemoteNestedExpands {
+  [key: string]: {
+    fields: string[]
+    args?: JoinerArgument[]
+    expands?: RemoteNestedExpands
+  }
+}
+
+export interface RemoteExpandProperty {
+  property: string
+  serviceConfig: JoinerServiceConfig
+  fields: string[]
+  args?: JoinerArgument[]
+  expands?: RemoteNestedExpands
+}

packages/utils/package.json

@@ -34,6 +34,6 @@
     "prepare": "cross-env NODE_ENV=production yarn run build",
     "build": "tsc --build",
     "watch": "tsc --build --watch",
-    "test": "jest --passWithNoTests src"
+    "test": "jest"
   }
 }

packages/utils/src/common/index.ts

@@ -2,6 +2,7 @@ export * from "./build-query"
 export * from "./errors"
 export * from "./generate-entity-id"
 export * from "./get-config-file"
+export * from "./handle-postgres-database-error"
 export * from "./is-date"
 export * from "./is-defined"
 export * from "./is-email"
@@ -17,5 +18,6 @@ export * from "./wrap-handler"
 export * from "./to-kebab-case"
 export * from "./to-camel-case"
 export * from "./stringify-circular"
-export * from "./build-query"
+export * from "./to-kebab-case"
-export * from "./handle-postgres-database-error"
+export * from "./to-pascal-case"
+export * from "./wrap-handler"

packages/utils/src/common/to-pascal-case.ts

@@ -0,0 +1,5 @@
+export function toPascalCase(s: string): string {
+  return s.replace(/(^\w|_\w)/g, (match) =>
+    match.replace(/_/g, "").toUpperCase()
+  )
+}

packages/utils/tsconfig.json

@@ -15,13 +15,15 @@
     "strictFunctionTypes": true,
     "noImplicitThis": true,
     "allowJs": true,
-    "skipLibCheck": true
+    "skipLibCheck": true,
+    "downlevelIteration": true
   },
   "include": ["src"],
   "exclude": [
     "dist",
     "./src/**/__tests__",
     "./src/**/__mocks__",
+    "./src/**/__fixtures__",
     "node_modules"
   ]
 }

yarn.lock

@@ -6458,6 +6458,20 @@ __metadata:
   languageName: unknown
   linkType: soft
 
+"@medusajs/orchestration@workspace:packages/orchestration":
+  version: 0.0.0-use.local
+  resolution: "@medusajs/orchestration@workspace:packages/orchestration"
+  dependencies:
+    "@medusajs/types": ^1.8.7
+    "@medusajs/utils": ^1.9.1
+    cross-env: ^5.2.1
+    graphql: ^16.6.0
+    jest: ^25.5.4
+    ts-jest: ^25.5.1
+    typescript: ^4.4.4
+  languageName: unknown
+  linkType: soft
+
 "@medusajs/product@workspace:packages/product":
   version: 0.0.0-use.local
   resolution: "@medusajs/product@workspace:packages/product"
@@ -6504,7 +6518,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@medusajs/types@^1.8.8, @medusajs/types@^1.8.9, @medusajs/types@workspace:^, @medusajs/types@workspace:packages/types":
+"@medusajs/types@^1.8.7, @medusajs/types@^1.8.8, @medusajs/types@^1.8.9, @medusajs/types@workspace:^, @medusajs/types@workspace:packages/types":
   version: 0.0.0-use.local
   resolution: "@medusajs/types@workspace:packages/types"
   dependencies:
@@ -23781,6 +23795,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"graphql@npm:^16.6.0":
+  version: 16.6.0
+  resolution: "graphql@npm:16.6.0"
+  checksum: 3a2c15ff58b69d017618d2b224fa6f3c4a7937e1f711c3a5e0948db536b4931e6e649560b53de7cc26735e027ceea6e2d0a6bb7c29fc4639b290313e3aa71618
+  languageName: node
+  linkType: hard
+
 "growly@npm:^1.3.0":
   version: 1.3.0
   resolution: "growly@npm:1.3.0"