Merge branch 'main' into cache-invalidation

.github/workflows/test.yml

@@ -38,7 +38,7 @@ jobs:
 
       - name: Upload coverage reports to Codecov
         if: ${{ matrix.platform == 'ubuntu-latest' && matrix.go-version == '1.22.x' }}
-        uses: codecov/codecov-action@v4.4.1
+        uses: codecov/codecov-action@v4.5.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./coverage.txt

ctx.go

@@ -859,6 +859,10 @@ func (c *DefaultCtx) Links(link ...string) {
 
 // Locals makes it possible to pass any values under keys scoped to the request
 // and therefore available to all following routes that match the request.
+//
+// All the values are removed from ctx after returning from the top
+// RequestHandler. Additionally, Close method is called on each value
+// implementing io.Closer before removing the value from ctx.
 func (c *DefaultCtx) Locals(key any, value ...any) any {
 	if len(value) == 0 {
 		return c.fasthttp.UserValue(key)
@@ -868,7 +872,12 @@ func (c *DefaultCtx) Locals(key any, value ...any) any {
 }
 
 // Locals function utilizing Go's generics feature.
-// This function allows for manipulating and retrieving local values within a request context with a more specific data type.
+// This function allows for manipulating and retrieving local values within a
+// request context with a more specific data type.
+//
+// All the values are removed from ctx after returning from the top
+// RequestHandler. Additionally, Close method is called on each value
+// implementing io.Closer before removing the value from ctx.
 func Locals[V any](c Ctx, key any, value ...V) V {
 	var v V
 	var ok bool

docs/api/ctx.md

@@ -945,10 +945,10 @@ app.Get("/", func(c fiber.Ctx) error {
 
 ## Locals
 
-A method that stores variables scoped to the request and, therefore, are available only to the routes that match the request.
+A method that stores variables scoped to the request and, therefore, are available only to the routes that match the request. The stored variables are removed after the request is handled. If any of the stored data implements the `io.Closer` interface, its `Close` method will be called before it's removed.
 
 :::tip
-This is useful if you want to pass some **specific** data to the next middleware.
+This is useful if you want to pass some **specific** data to the next middleware. Remember to perform type assertions when retrieving the data to ensure it is of the expected type. You can also use a non-exported type as a key to avoid collisions.
 :::
 
 ```go title="Signature"
@@ -957,26 +957,26 @@ func (c Ctx) Locals(key any, value ...any) any
 
 ```go title="Example"
 
-// key is an unexported type for keys defined in this package.
+// keyType is an unexported type for keys defined in this package.
 // This prevents collisions with keys defined in other packages.
-type key int
+type keyType int
 
 // userKey is the key for user.User values in Contexts. It is
 // unexported; clients use user.NewContext and user.FromContext
 // instead of using this key directly.
-var userKey key
+var userKey keyType
 
 app.Use(func(c fiber.Ctx) error {
-  c.Locals(userKey, "admin")
+  c.Locals(userKey, "admin") // Stores the string "admin" under a non-exported type key
   return c.Next()
 })
 
 app.Get("/admin", func(c fiber.Ctx) error {
-  if c.Locals(userKey) == "admin" {
+  user, ok := c.Locals(userKey).(string) // Retrieves the data stored under the key and performs a type assertion
+  if ok && user == "admin" {
     return c.Status(fiber.StatusOK).SendString("Welcome, admin!")
   }
   return c.SendStatus(fiber.StatusForbidden)
-
 })
 ```
 

docs/intro.md

@@ -21,9 +21,12 @@ go get github.com/gofiber/fiber/v3
 ```
 
 ### Zero Allocation
-Some values returned from **fiber.Ctx** are **not** immutable by default.
+Because fiber is optimized for **high-performance** care is needed when using **fiber.Ctx**:
 
-Because fiber is optimized for **high-performance**, values returned from **fiber.Ctx** are **not** immutable by default and **will** be re-used across requests. As a rule of thumb, you **must** only use context values within the handler, and you **must not** keep any references. As soon as you return from the handler, any values you have obtained from the context will be re-used in future requests and will change below your feet. Here is an example:
+- Some values returned from **fiber.Ctx** are **not** immutable by default, and **will** be re-used across requests.
+- **fiber.Ctx** is **not** thread-safe and **must not** be accessed concurrently by multiple goroutines, the immutable setting **does not** change this.
+
+As a rule of thumb, you **must** only use context values within the handler, and you **must not** keep any references. As soon as you return from the handler, any values you have obtained from the context will be re-used in future requests and will change below your feet. Here is an example:
 
 ```go
 func handler(c fiber.Ctx) error {
@@ -70,7 +73,7 @@ app := fiber.New(fiber.Config{
 })
 ```
 
-For more information, please check [**\#426**](https://github.com/gofiber/fiber/issues/426) and [**\#185**](https://github.com/gofiber/fiber/issues/185).
+For more information, please check [**\#426**](https://github.com/gofiber/fiber/issues/426), [**\#185**](https://github.com/gofiber/fiber/issues/185) and [**\#3012**](https://github.com/gofiber/fiber/issues/3012).
 
 ### Hello, World!