From 6bf98c66af0724cf520655217b36f46917a7242e Mon Sep 17 00:00:00 2001
From: Agnes Lin <agneslin.lin@ibm.com>
Date: Wed, 28 Aug 2019 17:13:18 -0400
Subject: [PATCH] feat(repository): add has-many-inclusion-resolver function
 and tests for flatten method

---
 .../has-many/has-many-repository.factory.ts   |  2 +-
 .../has-many/has-many.inclusion-resolver.ts   |  2 +-
 .../src/relations/relation.helpers.ts         | 35 +++++++++----------
 3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/packages/repository/src/relations/has-many/has-many-repository.factory.ts b/packages/repository/src/relations/has-many/has-many-repository.factory.ts
index 65e505826c1a..e95972b8cec1 100644
--- a/packages/repository/src/relations/has-many/has-many-repository.factory.ts
+++ b/packages/repository/src/relations/has-many/has-many-repository.factory.ts
@@ -29,7 +29,7 @@ export interface HasManyRepositoryFactory<
   /**
    * Use `resolver` property to obtain an InclusionResolver for this relation.
    */
-  inclusionResolver: InclusionResolver;
+  inclusionResolver: InclusionResolver<Entity, Target>;
 }
 
 /**
diff --git a/packages/repository/src/relations/has-many/has-many.inclusion-resolver.ts b/packages/repository/src/relations/has-many/has-many.inclusion-resolver.ts
index cf75daeade27..4339064daa84 100644
--- a/packages/repository/src/relations/has-many/has-many.inclusion-resolver.ts
+++ b/packages/repository/src/relations/has-many/has-many.inclusion-resolver.ts
@@ -24,7 +24,7 @@ export function createHasManyInclusionResolver<
   getTargetRepo: Getter<
     EntityCrudRepository<Target, TargetID, TargetRelations>
   >,
-): InclusionResolver {
+): InclusionResolver<Entity, Target> {
   const relationMeta = resolveHasManyMetadata(meta);
 
 return async function fetchHasManyModels(
diff --git a/packages/repository/src/relations/relation.helpers.ts b/packages/repository/src/relations/relation.helpers.ts
index 77c6169d7a6f..dc62260d1d92 100644
--- a/packages/repository/src/relations/relation.helpers.ts
+++ b/packages/repository/src/relations/relation.helpers.ts
@@ -133,7 +133,8 @@ function isInclusionAllowed<T extends Entity, Relations extends object = {}>(
   return allowed;
 }
 
-/** Returns an array of arrays. Each nested array has one or more instance
+/** 
+ * Returns an array of arrays. Each nested array has one or more instance
  * as a result of one to many relations.
  * 
  * @param sourceIds - One value or array of values of the target key
@@ -156,7 +157,8 @@ export function flattenTargetsOfOneToManyRelation<Target extends Entity>(
   return flattenMapByKeys(sourceIds, lookup);
 }
 
-/** Returns an array of instaces, which's indexes map the sourceIds' indexes 
+/** 
+ * Returns an array of instaces, which's indexes map the sourceIds' indexes 
  * 
  * @param sourceIds - One value or array of values (of the target key)
  * @param targetMap - a map that matches sourceIds with instances
@@ -166,24 +168,17 @@ export function flattenMapByKeys<T>(
   targetMap: Map<unknown, T>,
 ): (T | undefined)[] {
   const result: (T | undefined)[] = new Array(sourceIds.length);
-  // should we change the for loop to:
 
-  for (const ix in sourceIds) {
-    const key = sourceIds[ix];
-    const target = targetMap.get(key);
-    result[ix] = target;
-  }
-  // for(const i of sourceIds.keys()){
-  //   const key = sourceIds[i];
-  //   const target = targetMap.get(key);
-  //   result[i] = target;
-  // }
+  sourceIds.forEach((id, index) => {
+    const target = targetMap.get(id);
+    result[index] = target;
+  });
 
   return result;
 }
 
-// TODO(bajtos) add test coverage
-/** Returns a map which maps key values(ids) to instances.
+/** 
+ * Returns a map which maps key values(ids) to instances.
  * 
  * @param list - an array of instances
  * @param keyName - key name of the source
@@ -205,7 +200,9 @@ export function buildLookupMap<Key, InType, OutType = InType>(
   }
   return lookup;
 }
-/** returns value of a key. Aim to resolve ObjectId problem of Mongo
+
+/** 
+ * Returns value of a key. Aim to resolve ObjectId problem of Mongo
  * 
  * @param model - target model
  * @param keyName - target key that gets the value from
@@ -219,7 +216,8 @@ export function getKeyValue<T>(model: T, keyName: string) {
   return rawKey;
 }
 
-/** Returns an array of instance. For HasMany relation usage.
+/** 
+ * Returns an array of instance. For HasMany relation usage.
  * 
  * @param acc 
  * @param it 
@@ -229,7 +227,8 @@ export function reduceAsArray<T>(acc: T[] | undefined, it: T) {
   else acc = [it];
   return acc;
 }
-/** Returns a single of instance. For HasOne and BelongsTo relation usage.
+/** 
+ * Returns a single of instance. For HasOne and BelongsTo relation usage.
  * 
  * @param _acc 
  * @param it