From 047f83d0a2da3225fe370dd59a534d5650e2b9ea Mon Sep 17 00:00:00 2001
From: Josep M Sobrepere <josepot@gmail.com>
Date: Wed, 26 Aug 2020 19:30:07 +0200
Subject: [PATCH] chore(utils): collector abstraction to reduce bundle size

---
 packages/utils/src/collect.ts        | 35 ++---------------------
 packages/utils/src/collectValues.ts  | 42 ++++------------------------
 packages/utils/src/internal-utils.ts | 41 +++++++++++++++++++++++++--
 3 files changed, 48 insertions(+), 70 deletions(-)

diff --git a/packages/utils/src/collect.ts b/packages/utils/src/collect.ts
index 17f4e8a..cc07209 100644
--- a/packages/utils/src/collect.ts
+++ b/packages/utils/src/collect.ts
@@ -1,26 +1,17 @@
 import { GroupedObservable, Observable } from "rxjs"
 import {
-  takeUntil,
-  takeLast,
   startWith,
   endWith,
   ignoreElements,
-  publish,
-  mergeMap,
   map,
   distinctUntilChanged,
   skipWhile,
 } from "rxjs/operators"
-import { shareLatest } from "@react-rxjs/core"
-import { scanWithDefaultValue } from "./internal-utils"
+import { set, del, collector } from "./internal-utils"
 
 const defaultFilter = (source$: Observable<any>) =>
   source$.pipe(ignoreElements(), startWith(true), endWith(false))
 
-const set = "s" as const
-const del = "d" as const
-const complete = "c" as const
-
 /**
  * A pipeable operator that collects all the GroupedObservables emitted by
  * the source and emits a Map with the active inner observables
@@ -42,27 +33,7 @@ export const collect = <K, V>(
     : defaultFilter
 
   return (source$: Observable<GroupedObservable<K, V>>) =>
-    source$.pipe(
-      publish((multicasted$) =>
-        multicasted$.pipe(
-          mergeMap((o) => map((x) => ({ t: x ? set : del, o }))(enhancer(o))),
-          takeUntil(takeLast(1)(multicasted$)),
-        ),
-      ),
-      endWith({ t: complete }),
-      scanWithDefaultValue(
-        (acc, val) => {
-          if (val.t === set) {
-            acc.set(val.o.key, val.o)
-          } else if (val.t === del) {
-            acc.delete(val.o.key)
-          } else {
-            acc.clear()
-          }
-          return acc
-        },
-        () => new Map<K, GroupedObservable<K, V>>(),
-      ),
-      shareLatest(),
+    collector(source$, (o) =>
+      map((x) => ({ t: x ? set : del, k: o.key, v: o }))(enhancer(o)),
     )
 }
diff --git a/packages/utils/src/collectValues.ts b/packages/utils/src/collectValues.ts
index 60da2f1..1156394 100644
--- a/packages/utils/src/collectValues.ts
+++ b/packages/utils/src/collectValues.ts
@@ -1,14 +1,6 @@
 import { Observable, GroupedObservable } from "rxjs"
-import {
-  map,
-  mergeMap,
-  endWith,
-  publish,
-  takeLast,
-  takeUntil,
-} from "rxjs/operators"
-import { shareLatest } from "@react-rxjs/core"
-import { scanWithDefaultValue } from "./internal-utils"
+import { map, endWith } from "rxjs/operators"
+import { set, del, collector } from "./internal-utils"
 
 /**
  * A pipeable operator that collects all the GroupedObservables emitted by
@@ -17,31 +9,9 @@ import { scanWithDefaultValue } from "./internal-utils"
 export const collectValues = <K, V>() => (
   source$: Observable<GroupedObservable<K, V>>,
 ): Observable<Map<K, V>> =>
-  source$.pipe(
-    publish((multicasted$) =>
-      multicasted$.pipe(
-        mergeMap((inner$) =>
-          inner$.pipe(
-            map((v) => ({ t: "s" as const, k: inner$.key, v })),
-            endWith({ t: "d" as const, k: inner$.key }),
-          ),
-        ),
-        takeUntil(multicasted$.pipe(takeLast(1))),
-      ),
+  collector(source$, (inner$) =>
+    inner$.pipe(
+      map((v) => ({ t: set, k: inner$.key, v })),
+      endWith({ t: del, k: inner$.key }),
     ),
-    endWith({ t: "c" as const }),
-    scanWithDefaultValue(
-      (acc, val) => {
-        if (val.t === "s") {
-          acc.set(val.k, val.v)
-        } else if (val.t === "d") {
-          acc.delete(val.k)
-        } else {
-          acc.clear()
-        }
-        return acc
-      },
-      () => new Map<K, V>(),
-    ),
-    shareLatest(),
   )
diff --git a/packages/utils/src/internal-utils.ts b/packages/utils/src/internal-utils.ts
index a4a98ad..bed7003 100644
--- a/packages/utils/src/internal-utils.ts
+++ b/packages/utils/src/internal-utils.ts
@@ -1,5 +1,13 @@
-import { Observable, defer } from "rxjs"
-import { scan } from "rxjs/operators"
+import { Observable, defer, GroupedObservable } from "rxjs"
+import { shareLatest } from "@react-rxjs/core"
+import {
+  scan,
+  publish,
+  endWith,
+  takeLast,
+  takeUntil,
+  mergeMap,
+} from "rxjs/operators"
 
 export const defaultStart = <T>(value: T) => (source$: Observable<T>) =>
   new Observable<T>((observer) => {
@@ -28,3 +36,32 @@ export const scanWithDefaultValue = <I, O>(
     const seed = getSeed()
     return source.pipe(scan(accumulator, seed), defaultStart(seed))
   })
+
+export const set = "s" as const
+export const del = "d" as const
+export const complete = "c" as const
+
+export const collector = <K, V, VV>(
+  source: Observable<GroupedObservable<K, V>>,
+  enhancer: (
+    source: GroupedObservable<K, V>,
+  ) => Observable<{ t: "d"; k: K } | { t: "s"; k: K; v: VV }>,
+): Observable<Map<K, VV>> =>
+  source.pipe(
+    publish((x) => x.pipe(mergeMap(enhancer), takeUntil(takeLast(1)(x)))),
+    endWith({ t: complete }),
+    scanWithDefaultValue(
+      (acc, val) => {
+        if (val.t === set) {
+          acc.set(val.k, val.v)
+        } else if (val.t === del) {
+          acc.delete(val.k)
+        } else {
+          acc.clear()
+        }
+        return acc
+      },
+      () => new Map<K, VV>(),
+    ),
+    shareLatest(),
+  )