From b88f4e1b64170041a738c2f4a9dd3cb55c22a017 Mon Sep 17 00:00:00 2001
From: Alice Gaudon <alice@gaudon.pro>
Date: Mon, 7 Sep 2020 14:02:43 +0200
Subject: [PATCH] ModelRelation: deduplicate eagerloaded models

---
 src/db/ModelRelation.ts | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/db/ModelRelation.ts b/src/db/ModelRelation.ts
index 12ab91e..120ad05 100644
--- a/src/db/ModelRelation.ts
+++ b/src/db/ModelRelation.ts
@@ -70,7 +70,9 @@ export default abstract class ModelRelation<S extends Model, O extends Model, R
     protected abstract collectionToOutput(models: O[]): R;
 
     public async eagerLoad(relations: ModelRelation<S, O, R>[], subRelations: string[] = []): Promise<ModelQueryResult<O>> {
-        const ids = relations.map(r => r.getModelID()).filter(id => id !== null && id !== undefined);
+        const ids = relations.map(r => r.getModelID())
+            .filter(id => id !== null && id !== undefined)
+            .reduce((array: O[], val) => val in array ? array : [...array, val], []);
         if (ids.length === 0) return [];
 
         const query = this.makeQuery();
@@ -80,7 +82,8 @@ export default abstract class ModelRelation<S extends Model, O extends Model, R
     }
 
     public async populate(models: ModelQueryResult<O>): Promise<void> {
-        this.cachedModels = models.filter(m => m[this.dbProperties.foreignKey] === this.getModelID());
+        this.cachedModels = models.filter(m => m[this.dbProperties.foreignKey] === this.getModelID())
+            .reduce((array: O[], val) => array.find(v => v.equals(val)) ? array : [...array, val], []);
     }
 
     public async count(): Promise<number> {
@@ -177,7 +180,8 @@ export class ManyThroughModelRelation<S extends Model, O extends Model> extends
     }
 
     public async eagerLoad(relations: ModelRelation<S, O, O[]>[], subRelations: string[] = []): Promise<ModelQueryResult<O>> {
-        const ids = relations.map(r => r.getModelID());
+        const ids = relations.map(r => r.getModelID())
+            .reduce((array: O[], val) => val in array ? array : [...array, val], []);
         if (ids.length === 0) return [];
 
         const query = this.makeQuery();
@@ -191,7 +195,8 @@ export class ManyThroughModelRelation<S extends Model, O extends Model> extends
         const ids = models.pivot!
             .filter(p => p[`pivot.${this.dbProperties.localPivotKey}`] === this.getModelID())
             .map(p => p[`pivot.${this.dbProperties.foreignPivotKey}`]);
-        this.cachedModels = models.filter(m => ids.indexOf(m[this.dbProperties.foreignKey]) >= 0);
+        this.cachedModels = models.filter(m => ids.indexOf(m[this.dbProperties.foreignKey]) >= 0)
+            .reduce((array: O[], val) => array.find(v => v.equals(val)) ? array : [...array, val], []);
     }
 }