From 982dc853befe8ccf54163a0b145e563da06f5dc1 Mon Sep 17 00:00:00 2001
From: Sean Perkins <sean@ionic.io>
Date: Tue, 5 Apr 2022 12:12:13 -0400
Subject: [PATCH] fix(datetime): warn when parsing an invalid date value
 (#25049)

---
 core/src/components/datetime/datetime.tsx | 24 ++++++++++++++---------
 core/src/utils/logging/index.ts           |  9 +++++++++
 2 files changed, 24 insertions(+), 9 deletions(-)
 create mode 100644 core/src/utils/logging/index.ts

diff --git a/core/src/components/datetime/datetime.tsx b/core/src/components/datetime/datetime.tsx
index b4c38cb95e..396725828f 100644
--- a/core/src/components/datetime/datetime.tsx
+++ b/core/src/components/datetime/datetime.tsx
@@ -1,5 +1,6 @@
 import type { ComponentInterface, EventEmitter } from '@stencil/core';
 import { Component, Element, Event, Host, Method, Prop, State, Watch, h, writeTask } from '@stencil/core';
+import { printIonWarning } from '@utils/logging';
 import { caretDownSharp, caretUpSharp, chevronBack, chevronDown, chevronForward } from 'ionicons/icons';
 
 import { getIonMode } from '../../global/ionic-global';
@@ -298,15 +299,20 @@ export class Datetime implements ComponentInterface {
        * This allows us to update the current value's date/time display without
        * refocusing or shifting the user's display (leaves the user in place).
        */
-      const { month, day, year, hour, minute } = parseDate(this.value);
-      this.activePartsClone = {
-        ...this.activeParts,
-        month,
-        day,
-        year,
-        hour,
-        minute,
-      };
+      const valueDateParts = parseDate(this.value);
+      if (valueDateParts) {
+        const { month, day, year, hour, minute } = valueDateParts;
+        this.activePartsClone = {
+          ...this.activeParts,
+          month,
+          day,
+          year,
+          hour,
+          minute,
+        };
+      } else {
+        printIonWarning(`Unable to parse date string: ${this.value}. Please provide a valid ISO 8601 datetime string.`);
+      }
     }
 
     this.emitStyle();
diff --git a/core/src/utils/logging/index.ts b/core/src/utils/logging/index.ts
new file mode 100644
index 0000000000..ebfe9e2e5f
--- /dev/null
+++ b/core/src/utils/logging/index.ts
@@ -0,0 +1,9 @@
+/**
+ * Logs a warning to the console with an Ionic prefix
+ * to indicate the library that is warning the developer.
+ *
+ * @param message - The string message to be logged to the console.
+ */
+export const printIonWarning = (message: string) => {
+  return console.warn(`[Ionic Warning]: ${message}`);
+};