From b89942dbffbf554e879d45ff7b79f24dd77eee0e Mon Sep 17 00:00:00 2001
From: Aria Minaei <aria.minaei@gmail.com>
Date: Wed, 7 Jul 2021 11:50:23 +0200
Subject: [PATCH] Minor change to discoveryMechanism's api

---
 .../derivations/prism/discoveryMechanism.ts   | 25 +++++-----
 .../dataverse/src/derivations/prism/prism.ts  | 49 ++++++++++---------
 2 files changed, 38 insertions(+), 36 deletions(-)

diff --git a/packages/dataverse/src/derivations/prism/discoveryMechanism.ts b/packages/dataverse/src/derivations/prism/discoveryMechanism.ts
index 0ba7865..90b6e2a 100644
--- a/packages/dataverse/src/derivations/prism/discoveryMechanism.ts
+++ b/packages/dataverse/src/derivations/prism/discoveryMechanism.ts
@@ -10,12 +10,15 @@ function createMechanism() {
 
   type Collector = (d: IDerivation<$IntentionalAny>) => void
 
-  const collectObservedDependencies = (
-    cb: () => void,
-    collector: Collector,
-  ) => {
+  const pushCollector = (collector: Collector): void => {
     stack.push(collector)
-    cb()
+  }
+
+  const popCollector = (collector: Collector): void => {
+    const existing = stack.peek()
+    if (existing !== collector) {
+      throw new Error(`Popped collector is not on top of the stack`)
+    }
     stack.pop()
   }
 
@@ -46,18 +49,14 @@ function createMechanism() {
     stack.pop()
   }
 
-  const isCollectingDependencies = () => {
-    return stack.peek() !== noopCollector
-  }
-
   return {
     type: 'Dataverse_discoveryMechanism' as 'Dataverse_discoveryMechanism',
-    collectObservedDependencies,
     startIgnoringDependencies,
     stopIgnoringDependencies,
     reportResolutionStart,
     reportResolutionEnd,
-    isCollectingDependencies,
+    pushCollector,
+    popCollector,
   }
 }
 
@@ -85,10 +84,10 @@ function getSharedMechanism(): ReturnType<typeof createMechanism> {
 }
 
 export const {
-  collectObservedDependencies,
   startIgnoringDependencies,
   stopIgnoringDependencies,
   reportResolutionEnd,
   reportResolutionStart,
-  isCollectingDependencies,
+  pushCollector,
+  popCollector,
 } = getSharedMechanism()
diff --git a/packages/dataverse/src/derivations/prism/prism.ts b/packages/dataverse/src/derivations/prism/prism.ts
index 670e2a6..962aab0 100644
--- a/packages/dataverse/src/derivations/prism/prism.ts
+++ b/packages/dataverse/src/derivations/prism/prism.ts
@@ -4,9 +4,10 @@ import Stack from '../../utils/Stack'
 import AbstractDerivation from '../AbstractDerivation'
 import type {IDerivation} from '../IDerivation'
 import {
-  collectObservedDependencies,
   startIgnoringDependencies,
   stopIgnoringDependencies,
+  pushCollector,
+  popCollector,
 } from './discoveryMechanism'
 
 const voidFn = () => {}
@@ -44,28 +45,30 @@ export class PrismDerivation<V> extends AbstractDerivation<V> {
 
     const newDeps: Set<IDerivation<unknown>> = new Set()
     this._cacheOfDendencyValues.clear()
-    collectObservedDependencies(
-      () => {
-        hookScopeStack.push(this._prismScope)
-        try {
-          value = this._fn()
-        } catch (error) {
-          console.error(error)
-        } finally {
-          const topOfTheStack = hookScopeStack.pop()
-          if (topOfTheStack !== this._prismScope) {
-            console.warn(
-              // @todo guide the user to report the bug in an issue
-              `The Prism hook stack has slipped. This is a bug.`,
-            )
-          }
-        }
-      },
-      (observedDep) => {
-        newDeps.add(observedDep)
-        this._addDependency(observedDep)
-      },
-    )
+
+    const collector = (observedDep: IDerivation<unknown>): void => {
+      newDeps.add(observedDep)
+      this._addDependency(observedDep)
+    }
+
+    pushCollector(collector)
+
+    hookScopeStack.push(this._prismScope)
+    try {
+      value = this._fn()
+    } catch (error) {
+      console.error(error)
+    } finally {
+      const topOfTheStack = hookScopeStack.pop()
+      if (topOfTheStack !== this._prismScope) {
+        console.warn(
+          // @todo guide the user to report the bug in an issue
+          `The Prism hook stack has slipped. This is a bug.`,
+        )
+      }
+    }
+
+    popCollector(collector)
 
     this._dependencies.forEach((dep) => {
       if (!newDeps.has(dep)) {