refactor: Prevent reduce calls

src/storage/conversion/ChainedConverter.ts

@@ -188,13 +188,13 @@ export class ChainedConverter extends RepresentationConverter {
    * Will return undefined if there are no matches.
    */
   private findBest(paths: ConversionPath[]): ConversionPath | undefined {
-    // Need to use null instead of undefined so `reduce` doesn't take the first element of the array as `best`
-    return paths.reduce((best: ConversionPath | null, path): ConversionPath | null => {
+    let best: ConversionPath | undefined;
+    for (const path of paths) {
       if (path.weight > 0 && !(best && best.weight >= path.weight)) {
-        return path;
+        best = path;
       }
-      return best;
-    }, null) ?? undefined;
+    }
+    return best;
   }
 
   /**

src/storage/conversion/ConversionUtil.ts

@@ -113,20 +113,20 @@ export function getWeightedPreferences(types: ValuePreferences, preferred: Value
  * Undefined if there is no match.
  */
 export function getBestPreference(types: ValuePreferences, preferred: ValuePreferences): ValuePreference | undefined {
-  // Could also return the first entry of the above function but this is more efficient
-  const result = Object.entries(types).reduce((best, [ value, quality ]): ValuePreference => {
+  // Could also return the first entry of `getWeightedPreferences` but this is more efficient
+  let best: ValuePreference = { value: '', weight: 0 };
+  for (const [ value, quality ] of Object.entries(types)) {
     if (best.weight >= quality) {
-      return best;
+      continue;
     }
     const weight = quality * getTypeWeight(value, preferred);
     if (weight > best.weight) {
-      return { value, weight };
+      best = { value, weight };
     }
-    return best;
-  }, { value: '', weight: 0 });
+  }
 
-  if (result.weight > 0) {
-    return result;
+  if (best.weight > 0) {
+    return best;
   }
 }
 

src/storage/keyvalue/WrappedIndexedStorage.ts

@@ -526,7 +526,11 @@ export class WrappedIndexedStorage<T extends IndexTypeCollection<T>> implements
       indexResults.push(rootIds);
     }
 
-    return indexResults.reduce((acc, ids): string[] => acc.filter((id): boolean => ids.includes(id)));
+    let indexedRoots: string[] = indexResults[0];
+    for (const ids of indexResults.slice(1)) {
+      indexedRoots = indexedRoots.filter((id): boolean => ids.includes(id));
+    }
+    return indexedRoots;
   }
 
   /**
@@ -581,9 +585,13 @@ export class WrappedIndexedStorage<T extends IndexTypeCollection<T>> implements
     }
 
     // For all keys that were not handled recursively: make sure that it matches the found objects
-    const remainingKeys = Object.keys(query).filter((key): boolean =>
-      key !== relation?.child.key || typeof query[key] === 'string');
-    return remainingKeys.reduce((acc, key): any[] => acc.filter((obj): boolean => obj[key] === query[key]), objs);
+    const remainingKeys = Object.keys(query).filter(
+      (key): boolean => key !== relation?.child.key || typeof query[key] === 'string',
+    );
+    for (const key of remainingKeys) {
+      objs = objs.filter((obj): boolean => obj[key] === query[key]);
+    }
+    return objs;
   }
 
   // --------------------------------- INDEX HELPERS ---------------------------------

src/storage/size-reporter/FileSizeReporter.ts

@@ -71,17 +71,16 @@ export class FileSizeReporter implements SizeReporter<string> {
     const childFiles = await fsPromises.readdir(fileLocation);
     const rootFilePathLength = trimTrailingSlashes(this.rootFilePath).length;
 
-    return await childFiles.reduce(async(acc: Promise<number>, current): Promise<number> => {
+    let totalSize = stat.size;
+    for (const current of childFiles) {
       const childFileLocation = normalizeFilePath(joinFilePath(fileLocation, current));
-      let result = await acc;
 
       // Exclude internal files
       if (!this.ignoreFolders.some((folder: RegExp): boolean =>
         folder.test(childFileLocation.slice(rootFilePathLength)))) {
-        result += await this.getTotalSize(childFileLocation);
+        totalSize += await this.getTotalSize(childFileLocation);
       }
-
-      return result;
-    }, Promise.resolve(stat.size));
+    }
+    return totalSize;
   }
 }