Improve multiply-defined route error message (#127)

* A bunch of general cleanup
* Give a more informative/less incomprehensible error message when a route has been specified more than once.

.github/workflows/test.yml

@@ -16,14 +16,14 @@ jobs:
 
   upstream-check:
     runs-on: ubuntu-latest
-    container: swift:5.8-jammy
+    container: swift:5.9-jammy
     steps:
       - name: Check out self
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: routing-kit
       - name: Check out Vapor
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: vapor/vapor
           path: vapor

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.6
+// swift-tools-version:5.7
 import PackageDescription
 
 let package = Package(

README.md

@@ -6,10 +6,11 @@
     </picture> 
     <br>
     <br>
-<a href="https://docs.vapor.codes/4.0/"><img src="https://img.shields.io/badge/read_the-docs-2196f3.svg" alt="Documentation"></a>
-<a href="https://discord.gg/vapor"><img src="https://img.shields.io/discord/431917998102675485.svg" alt="Team Chat"></a>
-<a href="LICENSE"><img src="https://img.shields.io/badge/license-MIT-brightgreen.svg" alt="MIT License"></a>
+<a href="https://docs.vapor.codes/4.0/"><img src="https://img.shields.io/badge/read_the-docs-2196f3.svg?logo=data%3Aimage%2Fsvg%2Bxml%3Bbase64%2CPHN2ZyB2ZXJzaW9uPSIxLjEiIHZpZXdCb3g9IjAgMCAxNiAxNiIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48cmVjdCB4PSIxLjQiIHk9IjIuMzUiIHdpZHRoPSIxMy4yIiBoZWlnaHQ9IjkuOCIgc3R5bGU9ImZpbGw6ICNkZmRiZjM7IG9wYWNpdHk6IDAuMzMzMzM7Ii8%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%2BPC9zdmc%2BCg%3D%3D&labelColor=gray" alt="Documentation"></a>
+<a href="https://discord.gg/vapor"><img src="https://img.shields.io/discord/431917998102675485?logo=data%3Aimage%2Fsvg%2Bxml%3Bbase64%2CPHN2ZyBmaWxsPSIjOGY4ZmZmIiB2aWV3Qm94PSIwIDAgMjQgMjQiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI%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%2BPC9zdmc%2B&color=%238f8fff" alt="Team Chat"></a>
+<a href="LICENSE"><img src="https://img.shields.io/badge/license-MIT-skyblue?style=flat&logo=data%3Aimage%2Fsvg%2Bxml%3Bbase64%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%3D" alt="MIT License"></a>
 <a href="https://github.com/vapor/routing-kit/actions/workflows/test.yml"><img src="https://github.com/vapor/routing-kit/actions/workflows/test.yml/badge.svg" alt="Continuous Integration"></a>
-<a href="https://swift.org"><img src="https://img.shields.io/badge/swift-5.6-brightgreen.svg" alt="Swift 5.6"></a>
+<a href="https://codecov.io/github/vapor/routing-kit"><img src="https://codecov.io/github/vapor/routing-kit/branch/main/graph/badge.svg?token=yDzzHja8lt"></a>
+<a href="https://swift.org"><img src="https://img.shields.io/badge/swift-5.7%2b-white?style=flat&logo=data%3Aimage%2Fsvg%2Bxml%3Bbase64%2CPHN2ZyB2aWV3Qm94PSIwIDAgMjQgMjQiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI%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%3D%3D&logoColor=%23f07158&labelColor=gray&color=%23f07158" alt="Swift 5.7 - 5.9"></a>
 </p>
 <br>

Sources/RoutingKit/TrieRouter.swift

@@ -49,6 +49,8 @@ public final class TrieRouter<Output>: Router, CustomStringConvertible {
     /// - parameters:
     ///     - route: `Route` to register to this router.
     public func register(_ output: Output, at path: [PathComponent]) {
+        assert(!path.isEmpty, "Cannot register a route with an empty path.")
+
         // start at the root of the trie branch
         var current = self.root
 
@@ -66,7 +68,7 @@ public final class TrieRouter<Output>: Router, CustomStringConvertible {
 
         // if this node already has output, we are overriding a route
         if current.output != nil {
-            self.logger.info("[Routing] Overriding route output at: \(path.string)")
+            self.logger.info("[Routing] Overriding duplicate route for \(path[0]) \(path.dropFirst().string)")
         }
 
         // after iterating over all path components, we can set the output