From c9c56942fd22dcdeb288bd5533c7b3aa8635e26b Mon Sep 17 00:00:00 2001
From: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
Date: Thu, 7 Nov 2024 16:28:54 -0500
Subject: [PATCH 1/3] Ensure spacing utilities with no value (e.g. `px`) don't
 generate CSS

---
 packages/tailwindcss/src/utilities.test.ts | 16 ++++++++++++++++
 packages/tailwindcss/src/utilities.ts      |  6 +++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/packages/tailwindcss/src/utilities.test.ts b/packages/tailwindcss/src/utilities.test.ts
index 5af59338f096..8d0ed9b6a4d9 100644
--- a/packages/tailwindcss/src/utilities.test.ts
+++ b/packages/tailwindcss/src/utilities.test.ts
@@ -16124,6 +16124,22 @@ describe('spacing utilities', () => {
       }"
     `)
   })
+
+  test('spacing utilities must have a value', async () => {
+    let { build } = await compile(css`
+      @theme {
+        --spacing: 4px;
+      }
+      @tailwind utilities;
+    `)
+    let compiled = build(['px'])
+
+    expect(optimizeCss(compiled).trim()).toMatchInlineSnapshot(`
+      ":root {
+        --spacing: 4px;
+      }"
+    `)
+  })
 })
 
 describe('custom utilities', () => {
diff --git a/packages/tailwindcss/src/utilities.ts b/packages/tailwindcss/src/utilities.ts
index f57c4cccec9d..5778ec249436 100644
--- a/packages/tailwindcss/src/utilities.ts
+++ b/packages/tailwindcss/src/utilities.ts
@@ -278,7 +278,10 @@ export function createUtilities(theme: Theme) {
         // `defaultValue` (for candidates like `grow` that have no theme values)
         // or a bare theme value (like `--radius` for `rounded`). No utility
         // will ever support both of these.
-        value = desc.defaultValue ?? theme.resolve(null, desc.themeKeys ?? [])
+        value =
+          desc.defaultValue !== undefined
+            ? desc.defaultValue
+            : theme.resolve(null, desc.themeKeys ?? [])
       } else if (candidate.value.kind === 'arbitrary') {
         if (candidate.modifier) return
         value = candidate.value.value
@@ -394,6 +397,7 @@ export function createUtilities(theme: Theme) {
       themeKeys,
       supportsFractions,
       supportsNegative,
+      defaultValue: null,
       handleBareValue: ({ value }) => {
         let multiplier = theme.resolve(null, ['--spacing'])
         if (!multiplier) return null

From a2dc3d8bd13c522a1b65411be02d49a18689382b Mon Sep 17 00:00:00 2001
From: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
Date: Thu, 7 Nov 2024 20:59:21 -0500
Subject: [PATCH 2/3] Update test

---
 packages/tailwindcss/src/utilities.test.ts | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/packages/tailwindcss/src/utilities.test.ts b/packages/tailwindcss/src/utilities.test.ts
index 8d0ed9b6a4d9..84694d2d4846 100644
--- a/packages/tailwindcss/src/utilities.test.ts
+++ b/packages/tailwindcss/src/utilities.test.ts
@@ -16127,18 +16127,14 @@ describe('spacing utilities', () => {
 
   test('spacing utilities must have a value', async () => {
     let { build } = await compile(css`
-      @theme {
+      @theme reference {
         --spacing: 4px;
       }
       @tailwind utilities;
     `)
     let compiled = build(['px'])
 
-    expect(optimizeCss(compiled).trim()).toMatchInlineSnapshot(`
-      ":root {
-        --spacing: 4px;
-      }"
-    `)
+    expect(optimizeCss(compiled).trim()).toEqual('')
   })
 })
 

From f59ca2c514e79574e4bf32be0c20d4b6d06039a4 Mon Sep 17 00:00:00 2001
From: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
Date: Thu, 7 Nov 2024 21:00:23 -0500
Subject: [PATCH 3/3] Update changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b7a97d63d85e..d7fc139531b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Rebase `url()` inside imported CSS files when using Vite ([#14877](https://github.com/tailwindlabs/tailwindcss/pull/14877))
 - Ensure that CSS transforms from other Vite plugins correctly work in full builds (e.g. `:deep()` in Vue) ([#14871](https://github.com/tailwindlabs/tailwindcss/pull/14871))
 - Don't unset keys like `--inset-shadow-*` when unsetting keys like `--inset-*` ([#14906](https://github.com/tailwindlabs/tailwindcss/pull/14906))
+- Ensure spacing utilities with no value (e.g. `px` or `translate-y`) don't generate CSS ([#14911](https://github.com/tailwindlabs/tailwindcss/pull/14911))
 - _Upgrade (experimental)_: Install `@tailwindcss/postcss` next to `tailwindcss` ([#14830](https://github.com/tailwindlabs/tailwindcss/pull/14830))
 - _Upgrade (experimental)_: Remove whitespace around `,` separator when print arbitrary values ([#14838](https://github.com/tailwindlabs/tailwindcss/pull/14838))
 - _Upgrade (experimental)_: Fix crash during upgrade when content globs escape root of project ([#14896](https://github.com/tailwindlabs/tailwindcss/pull/14896))