From 8607ec34bfb487e138eef9f4a99f3c288233380f Mon Sep 17 00:00:00 2001
From: Michel Weststrate <mweststrate@gmail.com>
Date: Mon, 16 Apr 2018 20:23:10 +0200
Subject: [PATCH] Fixed #1480: exception in reaction effects where not handled
 correctly by the error handling system

---
 src/core/reaction.ts       | 20 +++++++++++++-------
 test/base/errorhandling.js | 26 ++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/src/core/reaction.ts b/src/core/reaction.ts
index ef3cebd62..87a44a79f 100644
--- a/src/core/reaction.ts
+++ b/src/core/reaction.ts
@@ -88,13 +88,17 @@ export class Reaction implements IDerivation, IReactionPublic {
             if (shouldCompute(this)) {
                 this._isTrackPending = true
 
-                this.onInvalidate()
-                if (this._isTrackPending && isSpyEnabled()) {
-                    // onInvalidate didn't trigger track right away..
-                    spyReport({
-                        name: this.name,
-                        type: "scheduled-reaction"
-                    })
+                try {
+                    this.onInvalidate()
+                    if (this._isTrackPending && isSpyEnabled()) {
+                        // onInvalidate didn't trigger track right away..
+                        spyReport({
+                            name: this.name,
+                            type: "scheduled-reaction"
+                        })
+                    }
+                } catch (e) {
+                    this.reportExceptionInDerivation(e)
                 }
             }
             endBatch()
@@ -135,6 +139,8 @@ export class Reaction implements IDerivation, IReactionPublic {
             return
         }
 
+        if (globalState.disableErrorBoundaries) throw error
+
         const message = `[mobx] Encountered an uncaught exception that was thrown by a reaction or observer component, in: '${this}`
         console.error(message, error)
         /** If debugging brought you here, please, read the above message :-). Tnx! */
diff --git a/test/base/errorhandling.js b/test/base/errorhandling.js
index e6f4c67fb..39a1d54cb 100644
--- a/test/base/errorhandling.js
+++ b/test/base/errorhandling.js
@@ -708,6 +708,32 @@ test("it should be possible to handle global errors in reactions", () => {
     })
 })
 
+test("it should be possible to handle global errors in reactions - 2 - #1480", () => {
+    utils.supressConsole(() => {
+        const a = mobx.observable.box(1)
+        const errors = []
+        const d2 = mobx.onReactionError(e => errors.push(e))
+
+        const d = mobx.reaction(
+            () => a.get(),
+            a => {
+                if (a >= 2) throw a
+            }
+        )
+
+        a.set(2)
+        a.set(3)
+
+        d2()
+        a.set(4)
+
+        expect(errors).toEqual([2, 3])
+        d()
+
+        checkGlobalState()
+    })
+})
+
 test("global error handling will be skipped when using disableErrorBoundaries - 1", () => {
     mobx.configure({ disableErrorBoundaries: true })
     try {