Add conic gradients to View backgroundImage

packages/react-native/Libraries/Components/View/__tests__/View-conicGradient-itest.js

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+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @fantom_flags enableNativeCSSParsing:*
+ * @fantom_flags enableCppPropsIteratorSetter:*
+ * @format
+ */
+
+import '@react-native/fantom/src/setUpDefaultReactNativeEnvironment';
+
+import type {ColorValue} from '../../../StyleSheet/StyleSheet';
+import type {
+  BackgroundImageValue,
+  RadialGradientPosition,
+} from '../../../StyleSheet/StyleSheetTypes';
+
+import * as Fantom from '@react-native/fantom';
+import * as React from 'react';
+import {View} from 'react-native';
+
+type BackgroundImage = string | ReadonlyArray<BackgroundImageValue>;
+
+function mountedBackgroundImage(backgroundImage: BackgroundImage): ?string {
+  const root = Fantom.createRoot();
+  Fantom.runTask(() => {
+    root.render(<View collapsable={false} style={{backgroundImage}} />);
+  });
+  return root.getRenderedOutput({props: ['backgroundImage']}).toJSONObject()
+    .props.backgroundImage;
+}
+
+const colors: ReadonlyArray<{
+  color: ColorValue,
+  positions?: ReadonlyArray<string>,
+}> = [{color: 'red'}, {color: 'blue'}];
+const serializedColors = 'rgba(255, 0, 0, 1), rgba(0, 0, 255, 1)';
+
+describe('conic gradient native props', () => {
+  // Assert the complete native value: matching only the right/bottom suffix
+  // would miss stale top/left defaults, which take precedence on iOS.
+  const positions: Array<{
+    css: string,
+    object: RadialGradientPosition,
+    expected: string,
+  }> = [
+    {css: 'center', object: {left: '50%', top: '50%'}, expected: '50% 50%'},
+    {
+      css: 'top center',
+      object: {left: '50%', top: '0%'},
+      expected: '50% 0%',
+    },
+    {
+      css: 'bottom center',
+      object: {left: '50%', top: '100%'},
+      expected: '50% 100%',
+    },
+    {
+      css: 'center left',
+      object: {left: '0%', top: '50%'},
+      expected: '0% 50%',
+    },
+    {
+      css: 'center right',
+      object: {left: '100%', top: '50%'},
+      expected: '100% 50%',
+    },
+    {css: '25% 75%', object: {left: '25%', top: '75%'}, expected: '25% 75%'},
+    {
+      css: 'left 10px top 20px',
+      object: {left: 10, top: 20},
+      expected: '10px 20px',
+    },
+    {
+      css: 'right 10px top 20px',
+      object: {right: 10, top: 20},
+      expected: '20px 10px',
+    },
+    {
+      css: 'left 10px bottom 20px',
+      object: {left: 10, bottom: 20},
+      expected: '10px 20px',
+    },
+    {
+      css: 'right 10px bottom 20px',
+      object: {right: 10, bottom: 20},
+      expected: '10px 20px',
+    },
+    {
+      css: 'bottom 20px right 10px',
+      object: {bottom: 20, right: 10},
+      expected: '10px 20px',
+    },
+    {
+      css: 'right 0px bottom 0px',
+      object: {right: 0, bottom: 0},
+      expected: '0px 0px',
+    },
+    {
+      css: 'right 10% bottom 20%',
+      object: {right: '10%', bottom: '20%'},
+      expected: '10% 20%',
+    },
+    {
+      css: 'right -10px bottom -20px',
+      object: {right: -10, bottom: -20},
+      expected: '-10px -20px',
+    },
+    {
+      css: 'right 110% bottom 120%',
+      object: {right: '110%', bottom: '120%'},
+      expected: '110% 120%',
+    },
+    {
+      css: 'right 0.5px bottom 1.25px',
+      object: {right: 0.5, bottom: 1.25},
+      expected: '0.5px 1.25px',
+    },
+  ];
+
+  for (const {css, object, expected} of positions) {
+    it(`preserves string position ${css}`, () => {
+      expect(
+        mountedBackgroundImage(
+          `conic-gradient(from 0deg at ${css}, red, blue)`,
+        ),
+      ).toBe(
+        `[conic-gradient(from 0deg at ${expected} , ${serializedColors})]`,
+      );
+    });
+    it(`preserves object position ${JSON.stringify(object)}`, () => {
+      expect(
+        mountedBackgroundImage([
+          {type: 'conic-gradient', position: object, colorStops: colors},
+        ]),
+      ).toBe(
+        `[conic-gradient(from 0deg at ${expected} , ${serializedColors})]`,
+      );
+    });
+  }
+
+  for (const {position, expected} of [
+    {position: {right: 10}, expected: '50% 10px'},
+    {position: {bottom: 20}, expected: '50% 20px'},
+    {position: {left: 10}, expected: '10px 50%'},
+    {position: {top: 20}, expected: '50% 20px'},
+  ]) {
+    it(`centers only the unspecified axis for ${JSON.stringify(position)}`, () => {
+      expect(
+        // $FlowFixMe[incompatible-type] - exercise partial positions from untyped callers.
+        mountedBackgroundImage([
+          {type: 'conic-gradient', position, colorStops: colors},
+        ]),
+      ).toBe(
+        `[conic-gradient(from 0deg at ${expected} , ${serializedColors})]`,
+      );
+    });
+  }
+
+  for (const [angle, expected] of [
+    ['0', '0'],
+    ['90deg', '90'],
+    ['100grad', '90'],
+    ['0.25turn', '90'],
+    ['-90deg', '-90'],
+    ['720deg', '720'],
+  ]) {
+    for (const syntax of ['string', 'object']) {
+      it(`preserves ${angle} in ${syntax} syntax`, () => {
+        const input: BackgroundImage =
+          syntax === 'string'
+            ? `conic-gradient(from ${angle}, red, blue)`
+            : [{type: 'conic-gradient', from: angle, colorStops: colors}];
+        expect(mountedBackgroundImage(input)).toBe(
+          `[conic-gradient(from ${expected}deg at 50% 50% , ${serializedColors})]`,
+        );
+      });
+    }
+  }
+
+  it('expands two-position hard stops without losing their order', () => {
+    expect(
+      mountedBackgroundImage(
+        'conic-gradient(red 0deg 90deg, blue 90deg 1turn)',
+      ),
+    ).toBe(
+      '[conic-gradient(from 0deg at 50% 50% , rgba(255, 0, 0, 1) 0%, rgba(255, 0, 0, 1) 25%, rgba(0, 0, 255, 1) 25%, rgba(0, 0, 255, 1) 100%)]',
+    );
+  });
+
+  it('accepts a single two-position hard stop', () => {
+    expect(mountedBackgroundImage('conic-gradient(red 0deg 360deg)')).toBe(
+      '[conic-gradient(from 0deg at 50% 50% , rgba(255, 0, 0, 1) 0%, rgba(255, 0, 0, 1) 100%)]',
+    );
+  });
+
+  for (const invalid of [
+    'conic-gradient()',
+    'conic-gradient(red)',
+    'conic-gradient(from 10px, red, blue)',
+    'conic-gradient(from 1, red, blue)',
+    'conic-gradient(from 50%, red, blue)',
+    'conic-gradient(from, red, blue)',
+    'conic-gradient(at, red, blue)',
+    'conic-gradient(at right left, red, blue)',
+    'conic-gradient(at left right, red, blue)',
+    'conic-gradient(at right 10px left 20px, red, blue)',
+    'conic-gradient(at 20px left, red, blue)',
+    'conic-gradient(at 20px right, red, blue)',
+    'conic-gradient(at top 20px, red, blue)',
+    'conic-gradient(at bottom 20px, red, blue)',
+    'conic-gradient(red 10px, blue)',
+    'conic-gradient(red 20, blue)',
+    'conic-gradient(20%, red, blue)',
+    'conic-gradient(red, blue, 20%)',
+    'conic-gradient(red, 20%, 30%, blue)',
+    'conic-gradient(red,, blue)',
+    'conic-gradient(, red, blue)',
+    'conic-gradient(red, blue,)',
+    'conic-gradient(red, not-a-color)',
+    'conic-gradient(from 90deg red, blue)',
+    'conic-gradient(at center red, blue)',
+  ]) {
+    it(`rejects ${invalid}`, () => {
+      expect(mountedBackgroundImage(invalid)).toBeUndefined();
+    });
+  }
+
+  for (const colorStops of [
+    [{color: 'red', positions: ['0deg', '45deg', '90deg']}, {color: 'blue'}],
+    [{positions: ['20%']}, {color: 'red'}, {color: 'blue'}],
+    [{color: 'red'}, {color: 'blue'}, {positions: ['20%']}],
+    [
+      {color: 'red'},
+      {positions: ['20%']},
+      {positions: ['30%']},
+      {color: 'blue'},
+    ],
+    [{color: 'red'}, {positions: ['20%', '30%']}, {color: 'blue'}],
+    [
+      {color: 'red'},
+      {color: 'not-a-color', positions: ['25%']},
+      {color: 'blue'},
+    ],
+  ]) {
+    it(`rejects malformed object stops through native props: ${JSON.stringify(colorStops)}`, () => {
+      const input = [{type: 'conic-gradient', colorStops}];
+      // $FlowFixMe[incompatible-type] - exercise malformed stops from untyped callers.
+      expect(mountedBackgroundImage(input)).toBeUndefined();
+    });
+  }
+
+  for (const color of [undefined, null]) {
+    it(`preserves a valid object hint with color ${String(color)}`, () => {
+      const input: BackgroundImage = [
+        {
+          type: 'conic-gradient',
+          colorStops: [
+            {color: 'red'},
+            {color, positions: ['90deg']},
+            {color: 'blue'},
+          ],
+        },
+      ];
+      expect(mountedBackgroundImage(input)).toBe(
+        '[conic-gradient(from 0deg at 50% 50% , rgba(255, 0, 0, 1), rgba(0, 0, 0, 0) 25%, rgba(0, 0, 255, 1))]',
+      );
+    });
+  }
+
+  it('preserves layer order when conic, linear, and radial gradients are mixed', () => {
+    expect(
+      mountedBackgroundImage(
+        'conic-gradient(red, blue), linear-gradient(red, blue), radial-gradient(red, blue)',
+      ),
+    ).toBe(
+      `[conic-gradient(from 0deg at 50% 50% , ${serializedColors}), linear-gradient(180deg, ${serializedColors}), radial-gradient(ellipse farthest-corner at 50% 50% , ${serializedColors})]`,
+    );
+  });
+
+  const updates: Array<{
+    name: string,
+    before: BackgroundImage,
+    after: BackgroundImage | void,
+    expected: ?string,
+  }> = [
+    {
+      name: 'replaces left/top with right/bottom',
+      before: 'conic-gradient(at left 30px top 40px, red, blue)',
+      after: [
+        {
+          type: 'conic-gradient',
+          position: {right: 10, bottom: 20},
+          colorStops: colors,
+        },
+      ],
+      expected: `[conic-gradient(from 0deg at 10px 20px , ${serializedColors})]`,
+    },
+    {
+      name: 'resets edge offsets to the default center',
+      before: 'conic-gradient(at right 10px bottom 20px, red, blue)',
+      after: 'conic-gradient(red, blue)',
+      expected: `[conic-gradient(from 0deg at 50% 50% , ${serializedColors})]`,
+    },
+    {
+      name: 'removes a gradient with an empty list',
+      before: 'conic-gradient(red, blue)',
+      after: [],
+      expected: undefined,
+    },
+    {
+      name: 'removes a gradient with undefined',
+      before: 'conic-gradient(red, blue)',
+      after: undefined,
+      expected: undefined,
+    },
+    {
+      name: 'clears a gradient after an invalid replacement',
+      before: 'conic-gradient(red, blue)',
+      after: 'conic-gradient(red 10px, blue)',
+      expected: undefined,
+    },
+    {
+      name: 'replaces a conic gradient with a linear gradient',
+      before: 'conic-gradient(red, blue)',
+      after: 'linear-gradient(red, blue)',
+      expected: `[linear-gradient(180deg, ${serializedColors})]`,
+    },
+    {
+      name: 'recovers after invalid input',
+      before: 'conic-gradient(red 10px, blue)',
+      after: 'conic-gradient(red, blue)',
+      expected: `[conic-gradient(from 0deg at 50% 50% , ${serializedColors})]`,
+    },
+  ];
+  for (const {name, before, after, expected} of updates) {
+    it(name, () => {
+      const root = Fantom.createRoot();
+      Fantom.runTask(() => {
+        root.render(
+          <View collapsable={false} style={{backgroundImage: before}} />,
+        );
+      });
+      Fantom.runTask(() => {
+        root.render(
+          <View collapsable={false} style={{backgroundImage: after}} />,
+        );
+      });
+      expect(
+        root.getRenderedOutput({props: ['backgroundImage']}).toJSONObject()
+          .props.backgroundImage,
+      ).toBe(expected);
+    });
+  }
+});