From c58e4367c7e604c2b647d6793af85a8001b4a8b3 Mon Sep 17 00:00:00 2001
From: Ahmad Reza <hungry.dev39@gmail.com>
Date: Fri, 14 Feb 2020 20:38:39 +0700
Subject: [PATCH 1/4] warn when using wrong implementation of getOptionSelected

---
 .../src/useAutocomplete/useAutocomplete.js          | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
index c8b32008482e56..31d28463a2e9b3 100644
--- a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
+++ b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
@@ -439,6 +439,19 @@ export default function useAutocomplete(props) {
       const item = newValue;
       newValue = Array.isArray(value) ? [...value] : [];
 
+      if (process.env.NODE_ENV !== 'production') {
+        const matches = newValue.filter(val => getOptionSelected(item, val));
+
+        if (matches.length > 1) {
+          console.error(
+            [
+              'Material-UI: the `getOptionSelected` method of useAutocomplete do not handle the arguments correctly.',
+              `The component expects a single value to match a given option but found ${matches}.`,
+            ].join('\n'),
+          );
+        }
+      }
+
       const itemIndex = findIndex(newValue, valueItem => getOptionSelected(item, valueItem));
 
       if (itemIndex === -1) {

From 063b38065e40b207e84808571dd06f15e81c1c17 Mon Sep 17 00:00:00 2001
From: Ahmad Reza <hungry.dev39@gmail.com>
Date: Sun, 16 Feb 2020 11:10:42 +0700
Subject: [PATCH 2/4] replace error message to reflect number of matches

---
 packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
index 31d28463a2e9b3..ff6cc8eeb74a2a 100644
--- a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
+++ b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
@@ -446,7 +446,7 @@ export default function useAutocomplete(props) {
           console.error(
             [
               'Material-UI: the `getOptionSelected` method of useAutocomplete do not handle the arguments correctly.',
-              `The component expects a single value to match a given option but found ${matches}.`,
+              `The component expects a single value to match a given option but found ${matches.length} matches`,
             ].join('\n'),
           );
         }

From 45c4d783bab8e78a2a3af9c06ec20f241e6cd605 Mon Sep 17 00:00:00 2001
From: Ahmad Reza <hungry.dev39@gmail.com>
Date: Sun, 16 Feb 2020 11:15:48 +0700
Subject: [PATCH 3/4] prettier

---
 .../material-ui-lab/src/useAutocomplete/useAutocomplete.js    | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
index ff6cc8eeb74a2a..9957ed76d7b23c 100644
--- a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
+++ b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
@@ -446,7 +446,9 @@ export default function useAutocomplete(props) {
           console.error(
             [
               'Material-UI: the `getOptionSelected` method of useAutocomplete do not handle the arguments correctly.',
-              `The component expects a single value to match a given option but found ${matches.length} matches`,
+              `The component expects a single value to match a given option but found ${
+                matches.length
+              } matches.`,
             ].join('\n'),
           );
         }

From 0bd00e08c06e875e4b702b12b8fe520d5ca014a6 Mon Sep 17 00:00:00 2001
From: Olivier Tassinari <olivier.tassinari@gmail.com>
Date: Thu, 20 Feb 2020 00:53:58 +0100
Subject: [PATCH 4/4] add test case

---
 .../src/Autocomplete/Autocomplete.test.js     | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/packages/material-ui-lab/src/Autocomplete/Autocomplete.test.js b/packages/material-ui-lab/src/Autocomplete/Autocomplete.test.js
index 1f9c5eec4286fa..bd9dc472f94d34 100644
--- a/packages/material-ui-lab/src/Autocomplete/Autocomplete.test.js
+++ b/packages/material-ui-lab/src/Autocomplete/Autocomplete.test.js
@@ -736,6 +736,36 @@ describe('<Autocomplete />', () => {
         'For the input option: "a", `getOptionLabel` returns: undefined',
       );
     });
+
+    it('warn if getOptionSelected match multiple values for a given option', () => {
+      const value = [{ id: '10', text: 'One' }, { id: '20', text: 'Two' }];
+      const options = [
+        { id: '10', text: 'One' },
+        { id: '20', text: 'Two' },
+        { id: '30', text: 'Three' },
+      ];
+
+      render(
+        <Autocomplete
+          {...defaultProps}
+          multiple
+          options={options}
+          value={value}
+          getOptionLabel={option => option.text}
+          getOptionSelected={option => value.find(v => v.id === option.id)}
+          renderInput={params => <TextField {...params} autoFocus />}
+        />,
+      );
+
+      fireEvent.keyDown(document.activeElement, { key: 'ArrowDown' });
+      fireEvent.keyDown(document.activeElement, { key: 'ArrowDown' });
+      fireEvent.keyDown(document.activeElement, { key: 'Enter' });
+
+      expect(consoleErrorMock.callCount()).to.equal(1); // strict mode renders twice
+      expect(consoleErrorMock.args()[0][0]).to.include(
+        'The component expects a single value to match a given option but found 2 matches.',
+      );
+    });
   });
 
   describe('prop: options', () => {