add support for css @property

.changeset/angry-rules-tease.md

@@ -0,0 +1,5 @@
+---
+"@vanilla-extract/babel-plugin-debug-ids": minor
+---
+
+Add support for `createVar` calls that declare `@property` rules

.changeset/modern-cobras-sort.md

@@ -0,0 +1,30 @@
+---
+"@vanilla-extract/css": minor
+---
+
+`keyframes`: Add support for a `vars` property to steps within `keyframes` declarations
+
+Example usage:
+
+```ts
+import { createVar, keyframes } from '@vanilla-extract/css';
+
+const angle = createVar({
+  syntax: '<angle>',
+  inherits: false,
+  initialValue: '0deg'
+});
+
+export const angleKeyframes = keyframes({
+  '0%': {
+    vars: {
+      [angle]: '0deg'
+    }
+  },
+  '100%': {
+    vars: {
+      [angle]: '360deg'
+    }
+  }
+});
+```

.changeset/poor-mirrors-care.md

@@ -0,0 +1,29 @@
+---
+"@vanilla-extract/css": minor
+---
+
+`createVar`: Add support for defining [`@property`] rules
+
+Example usage:
+
+```ts
+import { createVar } from '@vanilla-extract/css';
+
+export const myVar = createVar({
+  syntax: '<number>',
+  inherits: false,
+  initialValue: '0.5',
+});
+```
+
+This will generate the following CSS:
+
+```css
+@property --myVar__jteyb14 {
+  syntax: "<number>";
+  inherits: false;
+  initial-value: 0.5;
+}
+```
+
+[`@property`]: https://developer.mozilla.org/en-US/docs/Web/CSS/@property

examples/next/components/HelloWorld.css.ts

@@ -1,11 +1,34 @@
-import { style } from '@vanilla-extract/css';
+import { style, createVar, keyframes, fallbackVar } from '@vanilla-extract/css';
+
+const color = createVar();
+const angle = createVar({
+  syntax: '<angle>',
+  inherits: false,
+  initialValue: '0deg',
+});
+
+const angleKeyframes = keyframes({
+  '100%': {
+    vars: {
+      [angle]: '360deg',
+    },
+  },
+});
 
 export const root = style({
   background: 'pink',
   color: 'blue',
   padding: '16px',
-  transition: 'opacity .1s ease', // Testing autoprefixer
+  transition: `opacity .1s ease, color .1s ease`, // Testing autoprefixer
+  backgroundImage: `linear-gradient(${angle}, rgba(153, 70, 198, 0.35) 0%, rgba(28, 56, 240, 0.46) 100%)`,
+  animation: `${angleKeyframes} 7s infinite ease-in-out both`,
   ':hover': {
     opacity: 0.8,
+    color: color,
+  },
+
+  vars: {
+    [color]: '#fef',
+    [angle]: fallbackVar(angle, '138deg'),
   },
 });

fixtures/themed/src/styles.css.ts

@@ -64,12 +64,16 @@ globalStyle(`body ${iDunno}:after`, {
   content: "'I am content'",
 });
 
-const blankVar1 = createVar();
+const blankVar1 = createVar({
+  syntax: '<number>',
+  inherits: false,
+  initialValue: '0.5',
+});
 const blankVar2 = createVar();
 
 export const opacity = styleVariants(
   {
-    '1/2': fallbackVar(blankVar1, '0.5'),
+    '1/2': blankVar1,
     '1/4': fallbackVar(blankVar1, blankVar2, '0.25'),
   },
   (value) => ({

packages/babel-plugin-debug-ids/src/index.test.ts

@@ -217,6 +217,22 @@ describe('babel plugin', () => {
     `);
   });
 
+  it('should handle typed createVar assigned to const', () => {
+    const source = `
+      import { createVar } from '@vanilla-extract/css';
+
+      const myVar = createVar({ syntax: '*', inherits: true });
+    `;
+
+    expect(transform(source)).toMatchInlineSnapshot(`
+      import { createVar } from '@vanilla-extract/css';
+      const myVar = createVar({
+        syntax: '*',
+        inherits: true
+      }, "myVar");
+    `);
+  });
+
   it('should handle createContainer assigned to const', () => {
     const source = `
       import { createContainer } from '@vanilla-extract/css';

packages/babel-plugin-debug-ids/src/index.ts

@@ -31,7 +31,11 @@ const debuggableFunctionConfig = {
     maxParams: 2,
   },
   createVar: {
-    maxParams: 1,
+    maxParams: 2,
+    hasDebugId: ({ arguments: args }) => {
+      const previousArg = args[args.length - 1];
+      return t.isStringLiteral(previousArg) || t.isTemplateLiteral(previousArg);
+    },
   },
   recipe: {
     maxParams: 2,

packages/css/src/transformCss.test.ts

@@ -6,6 +6,14 @@ import { style } from './style';
 setFileScope('test');
 
 const testVar = createVar();
+const testPropertyVar = createVar(
+  {
+    syntax: '<angle>',
+    inherits: false,
+    initialValue: '0deg',
+  },
+  'test-property',
+);
 const style1 = style({});
 const style2 = style({});
 
@@ -1845,6 +1853,46 @@ describe('transformCss', () => {
     `);
   });
 
+  it('should handle animations with vars', () => {
+    expect(
+      transformCss({
+        composedClassLists: [],
+        localClassNames: ['testClass'],
+        cssObjs: [
+          {
+            type: 'keyframes',
+            name: 'myAnimation',
+            rule: {
+              from: {
+                vars: {
+                  '--my-var': 'red',
+                  [testVar]: 'green',
+                },
+              },
+              to: {
+                vars: {
+                  '--my-var': 'orange',
+                  [testVar]: 'blue',
+                },
+              },
+            },
+          },
+        ],
+      }).join('\n'),
+    ).toMatchInlineSnapshot(`
+      @keyframes myAnimation {
+        from {
+          --my-var: red;
+          --skkcyc0: green;
+        }
+        to {
+          --my-var: orange;
+          --skkcyc0: blue;
+        }
+      }
+    `);
+  });
+
   it('should handle font face', () => {
     expect(
       transformCss({
@@ -2022,7 +2070,7 @@ describe('transformCss', () => {
     `);
   });
 
-  it('should handle css vars', () => {
+  it('should handle simple css properties', () => {
     expect(
       transformCss({
         composedClassLists: [],
@@ -2076,6 +2124,60 @@ describe('transformCss', () => {
     `);
   });
 
+  it('should handle complicated css properties', () => {
+    expect(
+      transformCss({
+        composedClassLists: [],
+        localClassNames: ['testClass'],
+        cssObjs: [
+          {
+            type: 'local',
+            selector: 'testClass',
+            rule: {
+              display: 'block',
+              vars: {
+                '--my-var': 'red',
+                [testPropertyVar]: '10deg',
+              },
+              selectors: {
+                '&:nth-child(3)': {
+                  vars: {
+                    '--my-var': 'orange',
+                    [testPropertyVar]: '20deg',
+                  },
+                },
+              },
+              '@media': {
+                'screen and (min-width: 700px)': {
+                  vars: {
+                    '--my-var': 'yellow',
+                    [testPropertyVar]: '50deg',
+                  },
+                },
+              },
+            },
+          },
+        ],
+      }).join('\n'),
+    ).toMatchInlineSnapshot(`
+      .testClass {
+        --my-var: red;
+        --test-property__skkcyc1: 10deg;
+        display: block;
+      }
+      .testClass:nth-child(3) {
+        --my-var: orange;
+        --test-property__skkcyc1: 20deg;
+      }
+      @media screen and (min-width: 700px) {
+        .testClass {
+          --my-var: yellow;
+          --test-property__skkcyc1: 50deg;
+        }
+      }
+    `);
+  });
+
   it('should cast property values to pixels when relevant', () => {
     expect(
       transformCss({
@@ -2288,13 +2390,13 @@ describe('transformCss', () => {
         ],
       }).join('\n'),
     ).toMatchInlineSnapshot(`
-      .skkcyc2 .skkcyc1:before, .skkcyc2 .skkcyc1:after {
+      .skkcyc3 .skkcyc2:before, .skkcyc3 .skkcyc2:after {
         background: black;
       }
-      ._1g1ptzo1._1g1ptzo10 .skkcyc1 {
+      ._1g1ptzo1._1g1ptzo10 .skkcyc2 {
         background: blue;
       }
-      ._1g1ptzo10._1g1ptzo1 .skkcyc1 {
+      ._1g1ptzo10._1g1ptzo1 .skkcyc2 {
         background: blue;
       }
     `);

packages/css/src/transformCss.ts

@@ -13,6 +13,7 @@ import type {
   CSSSelectorBlock,
   Composition,
   WithQueries,
+  CSSPropertyBlock,
 } from './types';
 import { markCompositionUsed } from './adapter';
 import { forEach, omit, mapKeys } from './utils';
@@ -119,6 +120,7 @@ class Stylesheet {
   localClassNamesSearch: AhoCorasick;
   composedClassLists: Array<{ identifier: string; regex: RegExp }>;
   layers: Map<string, Array<string>>;
+  propertyRules: Array<CSSPropertyBlock>;
 
   constructor(
     localClassNames: Array<string>,
@@ -128,6 +130,7 @@ class Stylesheet {
     this.conditionalRulesets = [new ConditionalRuleset()];
     this.fontFaceRules = [];
     this.keyframesRules = [];
+    this.propertyRules = [];
     this.localClassNamesMap = new Map(
       localClassNames.map((localClassName) => [localClassName, localClassName]),
     );
@@ -150,10 +153,17 @@ class Stylesheet {
 
       return;
     }
+
+    if (root.type === 'property') {
+      this.propertyRules.push(root);
+
+      return;
+    }
+
     if (root.type === 'keyframes') {
       root.rule = Object.fromEntries(
         Object.entries(root.rule).map(([keyframe, rule]) => {
-          return [keyframe, this.transformProperties(rule)];
+          return [keyframe, this.transformVars(this.transformProperties(rule))];
         }),
       );
       this.keyframesRules.push(root);
@@ -582,6 +592,11 @@ class Stylesheet {
       css.push(renderCss({ '@font-face': fontFaceRule }));
     }
 
+    // Render property rules
+    for (const property of this.propertyRules) {
+      css.push(renderCss({ [`@property ${property.name}`]: property.rule }));
+    }
+
     // Render keyframes
     for (const keyframe of this.keyframesRules) {
       css.push(renderCss({ [`@keyframes ${keyframe.name}`]: keyframe.rule }));