Fix NumberInput empty values (#57142)

* Fix NumberInput empty values

* tests

* tests

public/app/core/components/OptionsUI/NumberInput.test.tsx

@@ -0,0 +1,110 @@
+import { render, screen, fireEvent } from '@testing-library/react';
+import React from 'react';
+
+import { NumberInput } from './NumberInput';
+
+const setup = (min?: number, max?: number) => {
+  const onChange = jest.fn();
+  render(<NumberInput value={15} onChange={onChange} max={max} min={min} />);
+  return {
+    input: screen.getByTestId('input-wrapper').firstChild?.firstChild as HTMLInputElement,
+    onChange,
+  };
+};
+
+describe('NumberInput', () => {
+  it('updated input correctly', () => {
+    const data = setup();
+
+    const tests = [
+      {
+        value: '-10',
+        expected: -10,
+        onChangeCalledWith: -10,
+      },
+      {
+        value: '',
+        expected: null,
+        onChangeCalledWith: undefined,
+      },
+      {
+        value: '100',
+        expected: 100,
+        onChangeCalledWith: 100,
+      },
+      {
+        value: '1asd',
+        expected: null,
+        onChangeCalledWith: undefined,
+      },
+      {
+        value: -100,
+        expected: -100,
+        onChangeCalledWith: -100,
+      },
+      {
+        value: 20,
+        expected: 20,
+        onChangeCalledWith: 20,
+      },
+      {
+        value: 0,
+        expected: 0,
+        onChangeCalledWith: 0,
+      },
+      {
+        value: '0',
+        expected: 0,
+        onChangeCalledWith: 0,
+      },
+    ];
+
+    tests.forEach((test, i) => {
+      fireEvent.blur(data.input, { target: { value: test.value } });
+      expect(data.onChange).toBeCalledWith(test.onChangeCalledWith);
+      expect(data.onChange).toBeCalledTimes(i + 1);
+      expect(data.input).toHaveValue(test.expected);
+    });
+  });
+
+  it('corrects input as per min and max', async () => {
+    const data = setup(-10, 10);
+    let input = data.input;
+
+    const tests = [
+      {
+        value: '-10',
+        expected: -10,
+        onChangeCalledWith: -10,
+      },
+      {
+        value: '-100',
+        expected: -10,
+        onChangeCalledWith: -10,
+      },
+      {
+        value: '10',
+        expected: 10,
+        onChangeCalledWith: 10,
+      },
+      {
+        value: '100',
+        expected: 10,
+        onChangeCalledWith: 10,
+      },
+      {
+        value: '5',
+        expected: 5,
+        onChangeCalledWith: 5,
+      },
+    ];
+
+    tests.forEach((test, i) => {
+      input = screen.getByTestId('input-wrapper').firstChild?.firstChild as HTMLInputElement;
+      fireEvent.blur(input, { target: { value: test.value } });
+      expect(data.onChange).toBeCalledWith(test.onChangeCalledWith);
+      expect(data.onChange).toBeCalledTimes(i + 1);
+      expect(screen.getByTestId('input-wrapper').firstChild?.firstChild).toHaveValue(test.expected);
+    });
+  });
+});

public/app/core/components/OptionsUI/NumberInput.tsx

@@ -50,10 +50,9 @@ export class NumberInput extends PureComponent<Props, State> {
     let newValue = '';
     const min = this.props.min;
     const max = this.props.max;
-    const currentValue = txt && +txt;
+    let currentValue = txt !== '' ? Number(txt) : undefined;
 
-    if (currentValue) {
-      if (!Number.isNaN(currentValue)) {
+    if (currentValue && !Number.isNaN(currentValue)) {
       if (min != null && currentValue < min) {
         newValue = min.toString();
         corrected = true;
@@ -61,23 +60,22 @@ export class NumberInput extends PureComponent<Props, State> {
         newValue = max.toString();
         corrected = true;
       } else {
-          newValue = txt;
-        }
+        newValue = txt ?? '';
       }
 
       this.setState({
-        text: newValue || '',
+        text: newValue,
         inputCorrected: corrected,
       });
+    }
 
     if (corrected) {
       this.updateValueDebounced();
     }
 
-      if (!isNaN(currentValue) && currentValue !== this.props.value) {
+    if (!Number.isNaN(currentValue) && currentValue !== this.props.value) {
       this.props.onChange(currentValue);
     }
-    }
   };
 
   updateValueDebounced = debounce(this.updateValue, 500); // 1/2 second delay