* MS CreateAccessor lets caller choose the "result comparer" for the …

…underlying "computed" call. This enables caching for some situations that weren't easily possible before; for more info, see: mobxjs/mobx#2437 (comment)

Dist/Accessors/@AccessorCallPlan.js

@@ -67,7 +67,7 @@ export class AccessorCallPlan {
     //uselessCachingWarned = false;
     //_lastCall_startTime?: number; // for debugging/profiling purposes only
     Call_OrReturnCache() {
-        var _a;
+        var _a, _b;
         // cache hit, return
         if (this.cachedResult_wrapper != null) {
             return this.cachedResult_wrapper.get();
@@ -87,6 +87,7 @@ export class AccessorCallPlan {
         this.cachedResult_wrapper = computed(() => this.accessorMeta.accessor.apply(this, this.callArgs), {
             name: `computedFn(${this.accessorMeta.accessor.name}#${++this.callPlanIndex})`,
             keepAlive: (_a = this.accessorMeta.options.cache_keepAlive) !== null && _a !== void 0 ? _a : false,
+            equals: (_b = this.accessorMeta.options.cache_comparer) !== null && _b !== void 0 ? _b : undefined,
         });
         // if/when the cached-result-wrapper becomes no-longer-observed, also clean up this call-plan object
         if (!this.accessorMeta.options.cache_keepAlive) {

Dist/Accessors/@AccessorMetadata.d.ts

@@ -1,4 +1,4 @@
-import { IComputedValueOptions } from "mobx";
+import { IComputedValueOptions, IEqualsComparer } from "mobx";
 import { Graphlink } from "../index.js";
 import { UT_StoreShape } from "../UserTypes.js";
 import { BailError } from "../Utils/General/BailManager.js";
@@ -8,6 +8,7 @@ export declare class AccessorOptions<RootState = any, DBShape = any> {
     static default: AccessorOptions<any, any>;
     graph?: Graphlink<RootState, DBShape>;
     cache: boolean;
+    cache_comparer?: IEqualsComparer<any>;
     cache_keepAlive: boolean;
     cache_unwrapArrays: boolean;
 }

Dist/Accessors/Helpers.d.ts

@@ -31,7 +31,7 @@ export declare type AddEffect = (effectFunc: EffectFunc) => void;
 /** Similar to GetAsync, except includes helper for delaying effect-execution (ie. mobx changes) till end, and without certain data-centric behaviors (like disabling db-cache during resolution). */
 export declare function WaitTillResolvedThenExecuteSideEffects({ resolveCondition, effectExecution, timeout, onTimeout, timeoutMessage, }: {
     resolveCondition?: "returns true" | "no bail-error" | "no error" | undefined;
-    effectExecution?: "plain" | "action" | undefined;
+    effectExecution?: "action" | "plain" | undefined;
     timeout?: number | n;
     onTimeout?: "resolve promise" | "reject promise" | "do nothing" | undefined;
     timeoutMessage?: string | undefined;

Source/Accessors/@AccessorCallPlan.ts

@@ -1,5 +1,5 @@
 import {IsPrimitive} from "js-vextensions";
-import {computed, IComputedValue, IComputedValueOptions, onBecomeUnobserved, _isComputingDerivation} from "mobx";
+import {comparer, computed, IComputedValue, IComputedValueOptions, onBecomeUnobserved, _isComputingDerivation} from "mobx";
 import {Graphlink, CatchBail} from "../index.js";
 import {UT_StoreShape} from "../UserTypes.js";
 import {AccessorMetadata, ProfilingInfo} from "./@AccessorMetadata.js";
@@ -122,6 +122,7 @@ export class AccessorCallPlan {
 		this.cachedResult_wrapper = computed(()=>this.accessorMeta.accessor.apply(this, this.callArgs), {
 			name: `computedFn(${this.accessorMeta.accessor.name}#${++this.callPlanIndex})`,
 			keepAlive: this.accessorMeta.options.cache_keepAlive ?? false,
+			equals: this.accessorMeta.options.cache_comparer ?? undefined,
 		});
 		// if/when the cached-result-wrapper becomes no-longer-observed, also clean up this call-plan object
 		if (!this.accessorMeta.options.cache_keepAlive) {

Source/Accessors/@AccessorMetadata.ts

@@ -1,5 +1,5 @@
 import {CE} from "js-vextensions";
-import {IComputedValue, IComputedValueOptions, computed, onBecomeUnobserved, _isComputingDerivation, onBecomeObserved} from "mobx"
+import {IComputedValue, IComputedValueOptions, computed, onBecomeUnobserved, _isComputingDerivation, onBecomeObserved, comparer, IEqualsComparer} from "mobx"
 import {Graphlink} from "../index.js";
 import {UT_StoreShape} from "../UserTypes.js";
 import {BailError} from "../Utils/General/BailManager.js";
@@ -19,6 +19,7 @@ export class AccessorOptions<RootState = any, DBShape = any> {
 	//graph: Graphlink<any, any>;
 
 	cache = true;
+	cache_comparer?: IEqualsComparer<any>;
 	cache_keepAlive = false;
 	cache_unwrapArrays = true;
 	//callArgToDependencyConvertorFunc?: CallArgToDependencyConvertorFunc;

Source/Components/DataCommitScheduler.ts

@@ -48,34 +48,32 @@ export class DataCommitScheduler {
 				// wrapping multiple commit-funcs in a single action is a nice idea, but the time-based throttling system doesn't really work then, since almost all the execution time is in running the reactions
 				// we leave it like this for now though, opting instead to rely on the "dataUpdateBuffering_commitSetMaxFuncCount" option
 				RunInAction("DataCommitScheduler.commit", ()=>{
-
-				const commitStartTime = Date.now();
-				let commitFuncsExecuted = 0;
-				while (commitFuncsLeftToRun.length > 0) {
-					const func = commitFuncsLeftToRun.shift()!;
-					func();
-					//RunInAction("DataCommitScheduler.commit", ()=>func());
-					commitFuncsExecuted++;
-					if (commitFuncsExecuted >= this.graph.options.dataUpdateBuffering_commitSetMaxFuncCount) {
-						break;
-					}
-					if (Date.now() - commitStartTime > this.graph.options.dataUpdateBuffering_commitSetMaxTime) {
-						break;
+					const commitStartTime = Date.now();
+					let commitFuncsExecuted = 0;
+					while (commitFuncsLeftToRun.length > 0) {
+						const func = commitFuncsLeftToRun.shift()!;
+						func();
+						//RunInAction("DataCommitScheduler.commit", ()=>func());
+						commitFuncsExecuted++;
+						if (commitFuncsExecuted >= this.graph.options.dataUpdateBuffering_commitSetMaxFuncCount) {
+							break;
+						}
+						if (Date.now() - commitStartTime > this.graph.options.dataUpdateBuffering_commitSetMaxTime) {
+							break;
+						}
 					}
-				}
 
-				// if we haven't run all the commit-funcs yet, schedule the next subset to run in a moment
-				if (commitFuncsLeftToRun.length > 0) {
-					setTimeout(ProceedWithCommitting, this.graph.options.dataUpdateBuffering_breakDuration);
-				} else {
-					this.scheduledCommit_status = "inactive";
+					// if we haven't run all the commit-funcs yet, schedule the next subset to run in a moment
+					if (commitFuncsLeftToRun.length > 0) {
+						setTimeout(ProceedWithCommitting, this.graph.options.dataUpdateBuffering_breakDuration);
+					} else {
+						this.scheduledCommit_status = "inactive";
 
-					// there were commit-funcs that wanted in on this set, but had to wait; kick off a new set for them
-					if (this.scheduledCommit_commitFuncs.length > 0) {
-						this.ScheduleDataUpdateCommit(()=>{});
+						// there were commit-funcs that wanted in on this set, but had to wait; kick off a new set for them
+						if (this.scheduledCommit_commitFuncs.length > 0) {
+							this.ScheduleDataUpdateCommit(()=>{});
+						}
 					}
-				}
-
 				});
 			};
 			ProceedWithCommitting();