feat(utils): define read only link (#9254)

packages/core/utils/src/modules-sdk/define-link.ts

@@ -7,6 +7,7 @@ export const DefineLinkSymbol = Symbol.for("DefineLink")
 export interface DefineLinkExport {
   [DefineLinkSymbol]: boolean
   serviceName: string
+  entity?: string
   entryPoint: string
 }
 
@@ -19,6 +20,17 @@ type InputSource = {
   primaryKey: string
 }
 
+type ReadOnlyInputSource = {
+  linkable:
+    | CombinedSource
+    | InputSource
+    | {
+        serviceName: string
+        entity?: string
+      }
+  field?: string
+}
+
 type InputToJson = {
   toJSON: () => InputSource
 }
@@ -27,10 +39,18 @@ type CombinedSource = Record<any, any> & InputToJson
 
 type InputOptions = {
   linkable: CombinedSource | InputSource
+  field?: string
   isList?: boolean
   deleteCascade?: boolean
 }
 
+type Shortcut = {
+  property: string
+  path: string
+  isList?: boolean
+  forwardArguments?: string | string[]
+}
+
 type ExtraOptions = {
   pk?: {
     [key: string]: string
@@ -40,10 +60,22 @@ type ExtraOptions = {
     idPrefix?: string
     extraColumns?: LinkModulesExtraFields
   }
+  readOnly?: boolean
+}
+
+type ReadOnlyExtraOptions = {
+  readOnly: true
+  isList?: boolean
+  shortcut?: Shortcut | Shortcut[]
 }
 
 type DefineLinkInputSource = InputSource | InputOptions | CombinedSource
 
+type DefineReadOnlyLinkInputSource =
+  | ReadOnlyInputSource
+  | InputOptions
+  | CombinedSource
+
 type ModuleLinkableKeyConfig = {
   module: string
   entity?: string
@@ -53,9 +85,7 @@ type ModuleLinkableKeyConfig = {
   deleteCascade?: boolean
   primaryKey: string
   alias: string
-  shortcuts?: {
-    [key: string]: string | { path: string; isList?: boolean }
-  }
+  shortcut?: Shortcut | Shortcut[]
 }
 
 function isInputOptions(input: any): input is InputOptions {
@@ -70,7 +100,33 @@ function isToJSON(input: any): input is InputToJson {
   return isObject(input) && input?.["toJSON"]
 }
 
-function prepareServiceConfig(input: DefineLinkInputSource) {
+function buildFieldAlias(fieldAliases?: Shortcut | Shortcut[]) {
+  if (!fieldAliases) {
+    return
+  }
+
+  const fieldAlias = {}
+
+  const shortcuts = Array.isArray(fieldAliases) ? fieldAliases : [fieldAliases]
+  for (const sc of shortcuts) {
+    const fwArgs = sc.forwardArguments
+      ? Array.isArray(sc.forwardArguments)
+        ? sc.forwardArguments
+        : [sc.forwardArguments]
+      : []
+    fieldAlias[sc.property] = {
+      path: sc.path,
+      isList: !!sc.isList,
+      forwardArgumentsOnPath: fwArgs,
+    }
+  }
+
+  return fieldAlias
+}
+
+function prepareServiceConfig(
+  input: DefineLinkInputSource | DefineReadOnlyLinkInputSource
+) {
   let serviceConfig = {} as ModuleLinkableKeyConfig
 
   if (isInputSource(input)) {
@@ -78,8 +134,8 @@ function prepareServiceConfig(input: DefineLinkInputSource) {
 
     serviceConfig = {
       key: source.linkable,
-      alias: source.alias ?? camelToSnakeCase(source.field),
-      field: source.field,
+      alias: source.alias ?? camelToSnakeCase(source.field ?? ""),
+      field: input.field ?? source.field,
       primaryKey: source.primaryKey,
       isList: false,
       deleteCascade: false,
@@ -93,8 +149,8 @@ function prepareServiceConfig(input: DefineLinkInputSource) {
 
     serviceConfig = {
       key: source.linkable,
-      alias: source.alias ?? camelToSnakeCase(source.field),
-      field: source.field,
+      alias: source.alias ?? camelToSnakeCase(source.field ?? ""),
+      field: input.field ?? source.field,
       primaryKey: source.primaryKey,
       isList: input.isList ?? false,
       deleteCascade: input.deleteCascade ?? false,
@@ -123,14 +179,27 @@ function prepareServiceConfig(input: DefineLinkInputSource) {
  * @param linkServiceOptions
  */
 export function defineLink(
-  leftService: DefineLinkInputSource,
-  rightService: DefineLinkInputSource,
-  linkServiceOptions?: ExtraOptions
+  leftService: DefineLinkInputSource | DefineReadOnlyLinkInputSource,
+  rightService: DefineLinkInputSource | DefineReadOnlyLinkInputSource,
+  linkServiceOptions?: ExtraOptions | ReadOnlyExtraOptions
 ): DefineLinkExport {
   const serviceAObj = prepareServiceConfig(leftService)
   const serviceBObj = prepareServiceConfig(rightService)
 
-  const output = { [DefineLinkSymbol]: true, serviceName: "", entryPoint: "" }
+  if (linkServiceOptions?.readOnly) {
+    return defineReadOnlyLink(
+      serviceAObj,
+      serviceBObj,
+      linkServiceOptions as ReadOnlyExtraOptions
+    ) as unknown as DefineLinkExport
+  }
+
+  const output = {
+    [DefineLinkSymbol]: true,
+    serviceName: "",
+    entity: "",
+    entryPoint: "",
+  }
 
   const register = function (
     modules: ModuleJoinerConfig[]
@@ -276,6 +345,9 @@ ${serviceBObj.module}: {
     )
 
     output.entryPoint = aliasA + "_" + aliasB
+    output.entity = toPascalCase(
+      ["Link", serviceAObj.module, aliasA, serviceBObj.module, aliasB].join("_")
+    )
 
     const linkDefinition: ModuleJoinerConfig = {
       serviceName: output.serviceName,
@@ -284,15 +356,7 @@ ${serviceBObj.module}: {
         {
           name: [output.entryPoint],
           args: {
-            entity: toPascalCase(
-              [
-                "Link",
-                serviceAObj.module,
-                aliasA,
-                serviceBObj.module,
-                aliasB,
-              ].join("_")
-            ),
+            entity: output.entity,
           },
         },
       ],
@@ -324,15 +388,15 @@ ${serviceBObj.module}: {
       extends: [
         {
           serviceName: serviceAObj.module,
-          fieldAlias: {
-            [serviceBObj.isList ? pluralize(aliasB) : aliasB]: {
-              path: aliasB + "_link." + aliasB,
-              isList: serviceBObj.isList,
-              forwardArgumentsOnPath: [aliasB + "_link." + aliasB],
-            },
-          },
+          fieldAlias: buildFieldAlias({
+            property: serviceBObj.isList ? pluralize(aliasB) : aliasB,
+            path: aliasB + "_link." + aliasB,
+            isList: serviceBObj.isList,
+            forwardArguments: [aliasB + "_link." + aliasB],
+          }),
           relationship: {
             serviceName: output.serviceName,
+            entity: output.entity,
             primaryKey: serviceAObj.key,
             foreignKey: serviceAPrimaryKey,
             alias: aliasB + "_link",
@@ -341,15 +405,15 @@ ${serviceBObj.module}: {
         },
         {
           serviceName: serviceBObj.module,
-          fieldAlias: {
-            [serviceAObj.isList ? pluralize(aliasA) : aliasA]: {
-              path: aliasA + "_link." + aliasA,
-              isList: serviceAObj.isList,
-              forwardArgumentsOnPath: [aliasA + "_link." + aliasA],
-            },
-          },
+          fieldAlias: buildFieldAlias({
+            property: serviceAObj.isList ? pluralize(aliasA) : aliasA,
+            path: aliasA + "_link." + aliasA,
+            isList: serviceAObj.isList,
+            forwardArguments: [aliasA + "_link." + aliasA],
+          }),
           relationship: {
             serviceName: output.serviceName,
+            entity: output.entity,
             primaryKey: serviceBObj.key,
             foreignKey: serviceBPrimaryKey,
             alias: aliasA + "_link",
@@ -375,3 +439,62 @@ ${serviceBObj.module}: {
 
   return output
 }
+
+function defineReadOnlyLink(
+  serviceAObj: ModuleLinkableKeyConfig,
+  serviceBObj: ModuleLinkableKeyConfig,
+  readOnlyLinkOptions?: ReadOnlyExtraOptions
+): void {
+  const register = function (
+    modules: ModuleJoinerConfig[]
+  ): ModuleJoinerConfig {
+    const serviceAInfo = modules.find(
+      (mod) => mod.serviceName === serviceAObj.module
+    )!
+    const serviceBInfo = modules.find(
+      (mod) => mod.serviceName === serviceBObj.module
+    )!
+
+    if (!serviceAInfo) {
+      throw new Error(`Service ${serviceAObj.module} was not found. If this is your module, make sure you set isQueryable to true in medusa-config.js:
+        
+${serviceAObj.module}: {
+  // ...
+  definition: {
+    isQueryable: true
+  }
+}`)
+    }
+    if (!serviceBInfo) {
+      throw new Error(`Service ${serviceBObj.module} was not found. If this is your module, make sure you set isQueryable to true in medusa-config.js:
+        
+${serviceBObj.module}: {
+  // ...
+  definition: {
+    isQueryable: true
+  }
+}`)
+    }
+
+    return {
+      isLink: true,
+      isReadOnlyLink: true,
+      extends: [
+        {
+          serviceName: serviceAObj.module,
+          fieldAlias: buildFieldAlias(readOnlyLinkOptions?.shortcut),
+          relationship: {
+            serviceName: serviceBObj.module,
+            entity: serviceBObj.entity,
+            primaryKey: serviceBObj.primaryKey,
+            foreignKey: serviceAObj.field,
+            alias: serviceBObj.alias,
+            isList: readOnlyLinkOptions?.isList ?? serviceAObj.isList,
+          },
+        },
+      ],
+    }
+  }
+
+  global.MedusaModule.setCustomLink(register)
+}