Reduce precision of oklab() arguments in test snapshots (#15210)

After the changes in #15201, our Windows CI started to fail. The problem
is that lightningcss now needs to convert `oklch` colors into the
`oklab` space to inline some `color-mix()` functions.

The problem, though, is that this calculation seems to have rounding
differences between macOS, Linux, and Windows. Since we still want to
_define the default color space in `oklch`_ and _use lightningcss as a
post-processor in our unit tests so we have a better coverage of the
output_, this PR attempts to fix the issue by adding a custom vitest
serializer. It will find usages of the `oklab()` function with arguments
that have lots of decimal places (at least 6 decimal places). What it
then does is simply cut off any excess decimal places to truncate the
output to 5 places. E.g.:

```diff
- oklab(62.7955% .224863 .125846 / .75);
+ oklab(62.7955% .22486 .12584 / .75);
```

## Test Plan

I updated the CI workflow file to make all three builds run in CI and
observed that they are now all green again.

<img width="609" alt="Screenshot 2024-11-27 at 14 54 52"
src="https://github.com/user-attachments/assets/73fe6da5-30e3-4fd4-83ea-115b1f1602a6">

packages/tailwindcss/src/__snapshots__/utilities.test.ts.snap

@@ -63,7 +63,7 @@ exports[`border-* 1`] = `
 }
 
 .border-\\[\\#0088cc\\]\\/50 {
-  border-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-\\[color\\:var\\(--my-color\\)\\] {
@@ -196,7 +196,7 @@ exports[`border-b-* 1`] = `
 }
 
 .border-b-\\[\\#0088cc\\]\\/50 {
-  border-bottom-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-bottom-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-b-\\[color\\:var\\(--my-color\\)\\] {
@@ -329,7 +329,7 @@ exports[`border-e-* 1`] = `
 }
 
 .border-e-\\[\\#0088cc\\]\\/50 {
-  border-inline-end-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-inline-end-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-e-\\[color\\:var\\(--my-color\\)\\] {
@@ -462,7 +462,7 @@ exports[`border-l-* 1`] = `
 }
 
 .border-l-\\[\\#0088cc\\]\\/50 {
-  border-left-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-left-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-l-\\[color\\:var\\(--my-color\\)\\] {
@@ -595,7 +595,7 @@ exports[`border-r-* 1`] = `
 }
 
 .border-r-\\[\\#0088cc\\]\\/50 {
-  border-right-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-right-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-r-\\[color\\:var\\(--my-color\\)\\] {
@@ -728,7 +728,7 @@ exports[`border-s-* 1`] = `
 }
 
 .border-s-\\[\\#0088cc\\]\\/50 {
-  border-inline-start-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-inline-start-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-s-\\[color\\:var\\(--my-color\\)\\] {
@@ -861,7 +861,7 @@ exports[`border-t-* 1`] = `
 }
 
 .border-t-\\[\\#0088cc\\]\\/50 {
-  border-top-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-top-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-t-\\[color\\:var\\(--my-color\\)\\] {
@@ -994,7 +994,7 @@ exports[`border-x-* 1`] = `
 }
 
 .border-x-\\[\\#0088cc\\]\\/50 {
-  border-inline-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-inline-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-x-\\[color\\:var\\(--my-color\\)\\] {
@@ -1127,7 +1127,7 @@ exports[`border-y-* 1`] = `
 }
 
 .border-y-\\[\\#0088cc\\]\\/50 {
-  border-block-color: oklab(59.9824% -.0672516 -.124144 / .5);
+  border-block-color: oklab(59.9824% -.06725 -.12414 / .5);
 }
 
 .border-y-\\[color\\:var\\(--my-color\\)\\] {

packages/tailwindcss/src/compat/plugin-api.test.ts

@@ -3462,7 +3462,7 @@ describe('matchUtilities()', () => {
         }
 
         .scrollbar-\\[\\#08c\\]\\/50 {
-          scrollbar-color: oklab(59.9824% -.0672516 -.124144 / .5);
+          scrollbar-color: oklab(59.9824% -.06725 -.12414 / .5);
         }
 
         .scrollbar-\\[2px\\] {

packages/tailwindcss/src/css-functions.test.ts

@@ -152,7 +152,7 @@ describe('theme function', () => {
           }
 
           .red {
-            color: oklab(62.7955% .224863 .125846 / .75);
+            color: oklab(62.7955% .22486 .12584 / .75);
           }"
         `)
       })
@@ -173,7 +173,7 @@ describe('theme function', () => {
           }
 
           .red {
-            color: oklab(62.7955% .224863 .125846 / .75);
+            color: oklab(62.7955% .22486 .12584 / .75);
           }"
         `)
       })
@@ -194,7 +194,7 @@ describe('theme function', () => {
           }
 
           .red {
-            color: oklab(62.7955% .224863 .125846 / .75);
+            color: oklab(62.7955% .22486 .12584 / .75);
           }"
         `)
       })
@@ -455,7 +455,7 @@ describe('theme function', () => {
           }
 
           .red {
-            color: oklab(62.7955% .224863 .125846 / .25);
+            color: oklab(62.7955% .22486 .12584 / .25);
           }"
         `)
       })
@@ -533,11 +533,11 @@ describe('theme function', () => {
         ).toMatchInlineSnapshot(`
           ":root {
             --color-red-500: red;
-            --color-foo: oklab(62.7955% .224863 .125846 / .5);
+            --color-foo: oklab(62.7955% .22486 .12584 / .5);
           }
 
           .red {
-            color: oklab(62.7955% .224863 .125846 / .25);
+            color: oklab(62.7955% .22486 .12584 / .25);
           }"
         `)
       })
@@ -581,7 +581,7 @@ describe('theme function', () => {
           }
 
           .red {
-            color: oklab(62.7955% .224863 .125846 / .5);
+            color: oklab(62.7955% .22486 .12584 / .5);
           }"
         `)
       })
@@ -873,13 +873,7 @@ describe('in plugins', () => {
           --color-red: oklch(62% 0.25 30);
           --color-orange: oklch(79% 0.17 70);
           --color-blue: oklch(45% 0.31 264);
-
-          /*
-            Using oklab because Lightning converts the color to oklab when using
-            color-mix() and the results are off by 0.00000001 between macOS and
-            Linux.
-          */
-          --color-pink: oklab(87% 0.07 0);
+          --color-pink: oklch(87% 0.07 7);
         }
         @layer utilities {
           @tailwind utilities;
@@ -915,8 +909,8 @@ describe('in plugins', () => {
         .my-base-rule {
           color: oklch(62% .25 30);
           background-color: oklch(45% .31 264);
-          border-color: oklab(87% .07 0 / .1);
-          outline-color: oklab(79% .0581434 .159748 / .15);
+          border-color: oklab(87% .06947 .00853 / .1);
+          outline-color: oklab(79% .05814 .15974 / .15);
         }
       }
 

packages/tailwindcss/src/index.test.ts

@@ -182,7 +182,7 @@ describe('arbitrary properties', () => {
   it('should generate arbitrary properties with modifiers', async () => {
     expect(await run(['[color:red]/50'])).toMatchInlineSnapshot(`
       ".\\[color\\:red\\]\\/50 {
-        color: oklab(62.7955% .224863 .125846 / .5);
+        color: oklab(62.7955% .22486 .12584 / .5);
       }"
     `)
   })

packages/tailwindcss/src/test-utils/custom-serializer.ts

@@ -0,0 +1,22 @@
+import type { SnapshotSerializer } from 'vitest'
+
+// We're reducing the precision of parameters to the `oklab()` function from
+// our snapshots as we've observed lightningcss generating different decimal
+// places in the last position when run on different operating systems.
+const HIGH_PRECISION_OKLAB = /oklab\(\d{1,2}\.?\d{0,4}% -?\.(\d{6,8}) -?\.(\d{6,8}) \/ \.\d{1,2}\)/g
+
+export default {
+  test(val) {
+    return typeof val === 'string' && val.match(HIGH_PRECISION_OKLAB) !== null
+  },
+  serialize(val, config, indentation, depth, refs, printer) {
+    if (typeof val !== 'string') {
+      throw new Error('This was already tested in the test() callback')
+    }
+
+    let replaced = val.replaceAll(HIGH_PRECISION_OKLAB, (match, first, second) => {
+      return match.replaceAll(first, first.slice(0, 5)).replaceAll(second, second.slice(0, 5))
+    })
+    return printer(replaced, config, indentation, depth, refs)
+  },
+} satisfies SnapshotSerializer

packages/tailwindcss/src/utilities.test.ts

@@ -8373,7 +8373,7 @@ test('accent', async () => {
     }
 
     .accent-\\[\\#0088cc\\]\\/50, .accent-\\[\\#0088cc\\]\\/\\[0\\.5\\], .accent-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      accent-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      accent-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .accent-current {
@@ -8488,7 +8488,7 @@ test('caret', async () => {
     }
 
     .caret-\\[\\#0088cc\\]\\/50, .caret-\\[\\#0088cc\\]\\/\\[0\\.5\\], .caret-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      caret-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      caret-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .caret-current {
@@ -8601,7 +8601,7 @@ test('divide-color', async () => {
     }
 
     :where(.divide-\\[\\#0088cc\\]\\/50 > :not(:last-child)), :where(.divide-\\[\\#0088cc\\]\\/\\[0\\.5\\] > :not(:last-child)), :where(.divide-\\[\\#0088cc\\]\\/\\[50\\%\\] > :not(:last-child)) {
-      border-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      border-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     :where(.divide-current > :not(:last-child)) {
@@ -10499,7 +10499,7 @@ test('bg', async () => {
     }
 
     .bg-\\[\\#0088cc\\]\\/50, .bg-\\[\\#0088cc\\]\\/\\[0\\.5\\], .bg-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      background-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      background-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .bg-\\[color\\:var\\(--some-var\\)\\] {
@@ -11113,7 +11113,7 @@ test('from', async () => {
     }
 
     .from-\\[\\#0088cc\\]\\/50, .from-\\[\\#0088cc\\]\\/\\[0\\.5\\], .from-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-gradient-from: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-gradient-from: oklab(59.9824% -.06725 -.12414 / .5);
       --tw-gradient-stops: var(--tw-gradient-via-stops, var(--tw-gradient-position, ) var(--tw-gradient-from) var(--tw-gradient-from-position), var(--tw-gradient-to) var(--tw-gradient-to-position));
     }
 
@@ -11349,7 +11349,7 @@ test('via', async () => {
     }
 
     .via-\\[\\#0088cc\\]\\/50, .via-\\[\\#0088cc\\]\\/\\[0\\.5\\], .via-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-gradient-via: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-gradient-via: oklab(59.9824% -.06725 -.12414 / .5);
       --tw-gradient-via-stops: var(--tw-gradient-position, ) var(--tw-gradient-from) var(--tw-gradient-from-position), var(--tw-gradient-via) var(--tw-gradient-via-position), var(--tw-gradient-to) var(--tw-gradient-to-position);
       --tw-gradient-stops: var(--tw-gradient-via-stops);
     }
@@ -11593,7 +11593,7 @@ test('to', async () => {
     }
 
     .to-\\[\\#0088cc\\]\\/50, .to-\\[\\#0088cc\\]\\/\\[0\\.5\\], .to-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-gradient-to: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-gradient-to: oklab(59.9824% -.06725 -.12414 / .5);
       --tw-gradient-stops: var(--tw-gradient-via-stops, var(--tw-gradient-position, ) var(--tw-gradient-from) var(--tw-gradient-from-position), var(--tw-gradient-to) var(--tw-gradient-to-position));
     }
 
@@ -12157,7 +12157,7 @@ test('fill', async () => {
     }
 
     .fill-\\[\\#0088cc\\]\\/50, .fill-\\[\\#0088cc\\]\\/\\[0\\.5\\], .fill-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      fill: oklab(59.9824% -.0672516 -.124144 / .5);
+      fill: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .fill-current {
@@ -12278,7 +12278,7 @@ test('stroke', async () => {
     }
 
     .stroke-\\[\\#0088cc\\]\\/50, .stroke-\\[\\#0088cc\\]\\/\\[0\\.5\\], .stroke-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      stroke: oklab(59.9824% -.0672516 -.124144 / .5);
+      stroke: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .stroke-\\[color\\:var\\(--my-color\\)\\] {
@@ -13276,7 +13276,7 @@ test('placeholder', async () => {
     }
 
     .placeholder-\\[\\#0088cc\\]\\/50::placeholder, .placeholder-\\[\\#0088cc\\]\\/\\[0\\.5\\]::placeholder, .placeholder-\\[\\#0088cc\\]\\/\\[50\\%\\]::placeholder {
-      color: oklab(59.9824% -.0672516 -.124144 / .5);
+      color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .placeholder-current::placeholder {
@@ -13401,7 +13401,7 @@ test('decoration', async () => {
     }
 
     .decoration-\\[\\#0088cc\\]\\/50, .decoration-\\[\\#0088cc\\]\\/\\[0\\.5\\], .decoration-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      text-decoration-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      text-decoration-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .decoration-\\[color\\:var\\(--my-color\\)\\] {
@@ -15180,7 +15180,7 @@ test('outline', async () => {
     }
 
     .outline-\\[\\#0088cc\\]\\/50, .outline-\\[\\#0088cc\\]\\/\\[0\\.5\\], .outline-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      outline-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      outline-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .outline-\\[black\\] {
@@ -15612,7 +15612,7 @@ test('text', async () => {
     }
 
     .text-\\[\\#0088cc\\]\\/50, .text-\\[\\#0088cc\\]\\/\\[0\\.5\\], .text-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      color: oklab(59.9824% -.0672516 -.124144 / .5);
+      color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .text-\\[color\\:var\\(--my-color\\)\\] {
@@ -15781,7 +15781,7 @@ test('shadow', async () => {
     }
 
     .shadow-\\[\\#0088cc\\]\\/50, .shadow-\\[\\#0088cc\\]\\/\\[0\\.5\\], .shadow-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-shadow-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-shadow-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .shadow-\\[color\\:var\\(--value\\)\\] {
@@ -16024,7 +16024,7 @@ test('inset-shadow', async () => {
     }
 
     .inset-shadow-\\[\\#0088cc\\]\\/50, .inset-shadow-\\[\\#0088cc\\]\\/\\[0\\.5\\], .inset-shadow-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-inset-shadow-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-inset-shadow-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .inset-shadow-\\[color\\:var\\(--value\\)\\] {
@@ -16273,7 +16273,7 @@ test('ring', async () => {
     }
 
     .ring-\\[\\#0088cc\\]\\/50, .ring-\\[\\#0088cc\\]\\/\\[0\\.5\\], .ring-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-ring-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-ring-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .ring-\\[color\\:var\\(--my-color\\)\\] {
@@ -16548,7 +16548,7 @@ test('inset-ring', async () => {
     }
 
     .inset-ring-\\[\\#0088cc\\]\\/50, .inset-ring-\\[\\#0088cc\\]\\/\\[0\\.5\\], .inset-ring-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-inset-ring-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-inset-ring-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .inset-ring-\\[color\\:var\\(--my-color\\)\\] {
@@ -16811,7 +16811,7 @@ test('ring-offset', async () => {
     }
 
     .ring-offset-\\[\\#0088cc\\]\\/50, .ring-offset-\\[\\#0088cc\\]\\/\\[0\\.5\\], .ring-offset-\\[\\#0088cc\\]\\/\\[50\\%\\] {
-      --tw-ring-offset-color: oklab(59.9824% -.0672516 -.124144 / .5);
+      --tw-ring-offset-color: oklab(59.9824% -.06725 -.12414 / .5);
     }
 
     .ring-offset-\\[color\\:var\\(--my-color\\)\\] {

packages/tailwindcss/vitest.config.ts

@@ -1,7 +1,12 @@
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
 import { defineConfig } from 'vitest/config'
 
+const __dirname = fileURLToPath(new URL('.', import.meta.url))
+
 export default defineConfig({
   test: {
+    snapshotSerializers: [path.resolve(__dirname, 'src/test-utils/custom-serializer.ts')],
     exclude: ['**/*.spec.?(c|m)[jt]s?(x)', 'integrations/**/*'],
   },
 })