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Walkthrough

Adds SkipUnmatchedRoutes to fiber.Config; implements App.routeExists and integrates an early-404 short-circuit into both default and custom request handlers when enabled; updates docs and adds tests plus two benchmarks.

Changes

SkipUnmatchedRoutes Feature

Sequence Diagram

sequenceDiagram
  participant Client
  participant Handler as defaultRequestHandler/customRequestHandler
  participant Config as app.config.SkipUnmatchedRoutes
  participant RouteChecker as App.routeExists
  participant Middleware as middleware chain
  participant Endpoint as matched endpoint route

  Client->>Handler: incoming HTTP request
  Handler->>Config: read SkipUnmatchedRoutes
  alt SkipUnmatchedRoutes == true
    Handler->>RouteChecker: routeExists(method, path)
    alt routeExists == false
      Handler->>Handler: return 404 StatusNotFound
    else routeExists == true
      Handler->>Middleware: enter middleware chain
      Middleware->>Endpoint: execute matched endpoint
    end
  else SkipUnmatchedRoutes == false
    Handler->>Middleware: enter middleware chain
    Middleware->>Endpoint: scan & execute matched endpoint
  end

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• gofiber/fiber#4233: Prior modifications to request handler selection and invocation paths used by this short-circuit integration.
• gofiber/fiber#3261: Earlier refactor of default/custom request handlers that this change builds upon.
• gofiber/fiber#3817: Related routing behavior changes affecting endpoint detection and 404 outcomes.

Possibly related issues

• 📝 [Proposal]: skip group/prefix middleware when no child route matches #4403: Implements an opt-in config plus route-existence check to short-circuit middleware for unmatched paths, matching this PR's objective.

Suggested labels

⚡️ Performance

Suggested reviewers

• sixcolors
• efectn
• gaby

Poem

🐰 I hopped through routes with whiskers keen,
I checked each path for places unseen.
When none replied, I paused, then fled—
A tiny 404, then off to my bed.
🥕 Hop, code, hop — the router's clean.

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.34%. Comparing base (5fe6c52) to head (666d5ca).
⚠️ Report is 37 commits behind head on main.

@@           Coverage Diff           @@
##             main    #4411   +/-   ##
=======================================
  Coverage   91.33%   91.34%           
=======================================
  Files         132      133    +1     
  Lines       13193    13250   +57     
=======================================
+ Hits        12050    12103   +53     
- Misses        724      727    +3     
- Partials      419      420    +1     

☔ View full report in Codecov by Harness.
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@muzzii255 pls check linter errors

@muzzii255 pls add something in the markdown docs for this feature

@ReneWerner87 done

@gaby pls check

@gaby pls check

When SkipUnmatchedRoutes the router matching logic runs twice for every request. This is not ideal.

@gaby @ReneWerner87 i tried multiple approach like defering the middlewares when SkipUnmatchedRoutes to prevent extra lookup or using the routeExists to match the route and send the route to next() which will run the middlewares, none of them worked really well. the only thing left is to rewrite the tree which i am not supporting as it might create more bugs in the future. since its an optional feature, user will know the cost of using it.

any approach will add an extra lookup on the tree except rewriting the tree, right now i am using a middleware from the PR #4406 on my codebase, it will be easier for me to just use the fiber's internal tree.

@muzzii255 I think in next() we can check. IsMatched() and if false call c.SendString(not found)

@muzzii255 I think in next() we can check. IsMatched() and if false call c.SendString(not found)

let me test it

@muzzii255 I think in next() we can check. IsMatched() and if false call c.SendString(not found)

in next() function this loop executes the middlewares before isMatched() is called, i can try defering the middleware execute by appending the handler to a slice, iterate and execute the middleware after if c.isMatched check

	// Loop over the route stack starting from previous index
	for indexRoute < lenr {
		// Increment route index
		indexRoute++

		// Get *Route
		route := tree[indexRoute]

		if route.mount {
			continue
		}

		// Check if it matches the request path
		if !route.match(detectionPath, path, &c.values) {
			continue
		}

		if c.shouldSkipNonUseRoutes && !route.use {
			continue
		}

		// Pass route reference and param values
		c.route = route
		// Non use handler matched
		if !route.use {
			c.isMatched = true
		}
		// Execute first handler of route
		if len(route.Handlers) > 0 {
			c.indexHandler = 0
			c.indexRoute = indexRoute
			return true, route.Handlers[0](c)
		}

		return true, nil // Stop scanning the stack
	}
	
	// If c.Next() does not match, return 404
	// If no match, scan stack again if other methods match the request
	// Moved from app.handler because middleware may break the route chain
	if c.isMatched {
		return false, ErrNotFound
	}

@muzzii255 I think in next() we can check. IsMatched() and if false call c.SendString(not found)

@gaby Do you mean inside next() do the endpoint scan first (before the main loop runs any middleware), and return ErrNotFound if nothing matches? Because checking IsMatched after the loop is too late — middleware has already executed by then, which defeats the feature.