refactor: rename VERCEL_SKEW_PROTECTION_ENABLED to NEXT_SKEW_PROTECTION_ENABLED

Updated environment variable name to use NEXT_ prefix instead of VERCEL_
for better Netlify branding consistency while maintaining the same functionality.

Changes:
- src/index.ts: Updated env var check and warning message
- src/build/functions/edge.ts: Updated env var checks in two locations
- tests/integration/skew-protection.test.ts: Updated test env setup
- CLAUDE.md: Updated documentation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: biilmann

CLAUDE.md

@@ -70,7 +70,7 @@ The `PluginContext` class (`src/build/plugin-context.ts`) centralizes build conf
 
 ### Skew Protection
 
-When `VERCEL_SKEW_PROTECTION_ENABLED=1` is set, the plugin automatically:
+When `NEXT_SKEW_PROTECTION_ENABLED=1` is set, the plugin automatically:
 
 1. **Sets deployment ID**: Maps `NETLIFY_DEPLOY_ID` to `VERCEL_DEPLOYMENT_ID` for Next.js compatibility
 2. **Creates edge function**: Generates a skew protection edge function at `___netlify-skew-protection`
@@ -105,7 +105,7 @@ Extensive test fixtures cover scenarios like:
 - `NETLIFY_NEXT_PLUGIN_SKIP` - Skip plugin execution entirely
 - `NEXT_PRIVATE_STANDALONE` - Enabled automatically for builds
 - `IS_LOCAL` - Indicates local development vs deployment
-- `VERCEL_SKEW_PROTECTION_ENABLED` - Enable Next.js skew protection (set to '1')
+- `NEXT_SKEW_PROTECTION_ENABLED` - Enable Next.js skew protection (set to '1')
 - `VERCEL_DEPLOYMENT_ID` - Set automatically from `NETLIFY_DEPLOY_ID` when skew protection is enabled
 
 ## Build Tools

src/build/functions/edge.ts

@@ -214,7 +214,7 @@ export const createEdgeHandlers = async (ctx: PluginContext) => {
   const edgeHandlerPromises = nextDefinitions.map((def) => createEdgeHandler(ctx, def))
 
   // Create skew protection handler if enabled
-  if (process.env.VERCEL_SKEW_PROTECTION_ENABLED === '1') {
+  if (process.env.NEXT_SKEW_PROTECTION_ENABLED === '1') {
     edgeHandlerPromises.push(createSkewProtectionHandler(ctx))
   }
 
@@ -223,7 +223,7 @@ export const createEdgeHandlers = async (ctx: PluginContext) => {
   const netlifyDefinitions = nextDefinitions.flatMap((def) => buildHandlerDefinition(ctx, def))
 
   // Add skew protection handler to manifest if enabled
-  if (process.env.VERCEL_SKEW_PROTECTION_ENABLED === '1') {
+  if (process.env.NEXT_SKEW_PROTECTION_ENABLED === '1') {
     const skewProtectionDefinition: ManifestFunction = {
       function: SKEW_PROTECTION_HANDLER_NAME,
       name: 'Next.js Skew Protection Handler',

src/index.ts

@@ -54,14 +54,14 @@ export const onPreBuild = async (options: NetlifyPluginOptions) => {
     process.env.NEXT_PRIVATE_STANDALONE = 'true'
 
     // Set up skew protection if enabled
-    if (process.env.VERCEL_SKEW_PROTECTION_ENABLED === '1') {
+    if (process.env.NEXT_SKEW_PROTECTION_ENABLED === '1') {
       // Use Netlify's deploy ID as the deployment ID for Next.js
       const deployId = process.env.NETLIFY_DEPLOY_ID
       if (deployId) {
         process.env.VERCEL_DEPLOYMENT_ID = deployId
         console.log('[Skew Protection] Enabled with deployment ID:', deployId)
       } else {
-        console.warn('[Skew Protection] VERCEL_SKEW_PROTECTION_ENABLED is set but NETLIFY_DEPLOY_ID is not available')
+        console.warn('[Skew Protection] NEXT_SKEW_PROTECTION_ENABLED is set but NETLIFY_DEPLOY_ID is not available')
       }
     }
 

tests/integration/skew-protection.test.ts

@@ -9,7 +9,7 @@ describe('skew protection', () => {
     ctx = new FixtureTestContext({
       name: 'skew-protection',
       env: {
-        VERCEL_SKEW_PROTECTION_ENABLED: '1',
+        NEXT_SKEW_PROTECTION_ENABLED: '1',
         NETLIFY_DEPLOY_ID: 'test-deploy-123',
       },
     })