From 45374ea8651048627c7b13b176e38506aea80a24 Mon Sep 17 00:00:00 2001
From: Pedro Chambino <pchambino@gmail.com>
Date: Fri, 3 May 2019 16:39:14 +0100
Subject: [PATCH 1/4] Add onSetupError

---
 src/index.js | 59 +++++++++++++++++++++++++++++++---------------------
 1 file changed, 35 insertions(+), 24 deletions(-)

diff --git a/src/index.js b/src/index.js
index bcad4ec..8741bf3 100644
--- a/src/index.js
+++ b/src/index.js
@@ -36,7 +36,13 @@ const elmWebComponents = {
   register(
     name,
     ElmComponent,
-    { setupPorts = () => {}, staticFlags = {}, onDetached = () => {}, mapFlags = flags => flags } = {}
+    {
+      setupPorts = () => {},
+      staticFlags = {},
+      onDetached = () => {},
+      mapFlags = flags => flags,
+      onSetupError = () => {}
+    } = {}
   ) {
     if (!this.__elmVersion) {
       if (!hasWarnedAboutMissingElmVersion) {
@@ -56,29 +62,34 @@ const elmWebComponents = {
 
     class ElmElement extends HTMLElement {
       connectedCallback() {
-        let props = Object.assign({}, getProps(this), staticFlags)
-        if (Object.keys(props).length === 0) props = undefined
-
-        const flags = mapFlags(props)
-
-        if (elmVersion === '0.19') {
-          /* a change in Elm 0.19 means that ElmComponent.init now replaces the node you give it
-           * whereas in 0.18 it rendered into it. To avoid Elm therefore destroying our custom element
-           * we create a div that we let Elm render into, and manually clear any pre-rendered contents.
-           */
-          const elmDiv = document.createElement('div')
-
-          this.innerHTML = ''
-          this.appendChild(elmDiv)
-
-          const elmElement = ElmComponent.init({
-            flags,
-            node: elmDiv,
-          })
-          setupPorts(elmElement.ports)
-        } else if (elmVersion === '0.18') {
-          const elmElement = ElmComponent.embed(this, flags)
-          setupPorts(elmElement.ports)
+        try {
+          let props = Object.assign({}, getProps(this), staticFlags)
+          if (Object.keys(props).length === 0) props = undefined
+
+          const flags = mapFlags(props)
+
+          if (elmVersion === '0.19') {
+            /* a change in Elm 0.19 means that ElmComponent.init now replaces the node you give it
+             * whereas in 0.18 it rendered into it. To avoid Elm therefore destroying our custom element
+             * we create a div that we let Elm render into, and manually clear any pre-rendered contents.
+             */
+            const elmDiv = document.createElement('div')
+
+            this.innerHTML = ''
+            this.appendChild(elmDiv)
+
+            const elmElement = ElmComponent.init({
+              flags,
+              node: elmDiv,
+            })
+            setupPorts(elmElement.ports)
+          } else if (elmVersion === '0.18') {
+            const elmElement = ElmComponent.embed(this, flags)
+            setupPorts(elmElement.ports)
+          }
+        } catch (error) {
+          onSetupError(error)
+          throw error
         }
       }
 

From b571aaf4a39a1a5fb46f67a8de3bcfd7d32505f3 Mon Sep 17 00:00:00 2001
From: Pedro Chambino <pchambino@gmail.com>
Date: Tue, 7 May 2019 14:44:18 +0100
Subject: [PATCH 2/4] Use console.error instead of re-throwing the error

---
 src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 8741bf3..05582e9 100644
--- a/src/index.js
+++ b/src/index.js
@@ -88,8 +88,8 @@ const elmWebComponents = {
             setupPorts(elmElement.ports)
           }
         } catch (error) {
+          console.error(error)
           onSetupError(error)
-          throw error
         }
       }
 

From ddb1b54877c5afd057d0e5213868a5c6a4b21b9e Mon Sep 17 00:00:00 2001
From: Pedro Chambino <pchambino@gmail.com>
Date: Tue, 7 May 2019 15:44:44 +0100
Subject: [PATCH 3/4] Pass flags as context to the error

---
 src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 05582e9..0ec8b75 100644
--- a/src/index.js
+++ b/src/index.js
@@ -89,7 +89,7 @@ const elmWebComponents = {
           }
         } catch (error) {
           console.error(error)
-          onSetupError(error)
+          onSetupError(error, flags)
         }
       }
 

From e883584ed734964933340043555ac08fe9aa0bf9 Mon Sep 17 00:00:00 2001
From: Pedro Chambino <pchambino@gmail.com>
Date: Tue, 7 May 2019 16:45:52 +0100
Subject: [PATCH 4/4] Add error context object

---
 src/index.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 0ec8b75..b39f6f0 100644
--- a/src/index.js
+++ b/src/index.js
@@ -62,11 +62,13 @@ const elmWebComponents = {
 
     class ElmElement extends HTMLElement {
       connectedCallback() {
+        const context = {};
         try {
           let props = Object.assign({}, getProps(this), staticFlags)
           if (Object.keys(props).length === 0) props = undefined
 
           const flags = mapFlags(props)
+          context.flags = flags;
 
           if (elmVersion === '0.19') {
             /* a change in Elm 0.19 means that ElmComponent.init now replaces the node you give it
@@ -89,7 +91,7 @@ const elmWebComponents = {
           }
         } catch (error) {
           console.error(error)
-          onSetupError(error, flags)
+          onSetupError(error, context)
         }
       }