From ca753e7e59b45a6397d8a296ac9e55fe3af954b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carl=20G=C3=BCtzkow?=
 <70779496+CJGutz@users.noreply.github.com>
Date: Sat, 31 Aug 2024 21:11:32 +0200
Subject: [PATCH] rework matching of rotues with wildcards. With zip longest
 method

---
 unchained/src/lib.rs         |  1 +
 unchained/src/router.rs      | 79 ++++++++++++++++++++++++++++--------
 unchained/src/zip_longest.rs | 46 +++++++++++++++++++++
 3 files changed, 110 insertions(+), 16 deletions(-)
 create mode 100644 unchained/src/zip_longest.rs

diff --git a/unchained/src/lib.rs b/unchained/src/lib.rs
index c8353f6..4144ea9 100644
--- a/unchained/src/lib.rs
+++ b/unchained/src/lib.rs
@@ -3,3 +3,4 @@ pub mod router;
 pub mod server;
 pub mod templates;
 pub mod workers;
+pub mod zip_longest;
diff --git a/unchained/src/router.rs b/unchained/src/router.rs
index 0f7963f..4cdcc35 100644
--- a/unchained/src/router.rs
+++ b/unchained/src/router.rs
@@ -1,5 +1,7 @@
 use std::{collections::HashMap, fmt::Display, path::PathBuf};
 
+use crate::zip_longest::ZipLongest;
+
 #[derive(Clone, Debug)]
 pub struct Request {
     pub verb: String,
@@ -122,7 +124,6 @@ fn compare_route_w_path_and_get_path_params(
 ) -> (bool, HashMap<String, String>) {
     let route_parts = route
         .trim_start_matches('/')
-        .trim_end_matches('*')
         .trim_end_matches('/')
         .split('/')
         .filter(|s| !s.is_empty())
@@ -135,24 +136,30 @@ fn compare_route_w_path_and_get_path_params(
     let mut params = HashMap::new();
     let mut match_route = true;
     let last_is_star = route.ends_with('*');
-    for (count, req_part) in req_parts.clone().enumerate() {
-        let route_part = route_parts.get(count);
-        if route_part.is_none() {
-            match_route = last_is_star;
-            break;
-        }
-        let route_part = *route_part.unwrap();
 
-        if let Some(route_part) = route_part.strip_prefix(':') {
-            params.insert(route_part.to_string(), req_part.to_string());
-        } else if route_part != req_part {
-            match_route = false;
-            break;
+    for (route_part, req_part) in route_parts.iter().zip_longest(req_parts) {
+        match (route_part, req_part) {
+            (None, None) => break,
+            (None, Some(_)) => {
+                match_route = last_is_star;
+                break;
+            }
+            (Some(part), None) => {
+                match_route = *part == "*";
+                break;
+            }
+            (Some(route_part), Some(req_part)) => {
+                if let Some(route_no_prefix) = route_part.strip_prefix(':') {
+                    params.insert(route_no_prefix.to_string(), req_part.to_string());
+                } else if *route_part != req_part {
+                    match_route = *route_part == "*";
+                    if !match_route {
+                        break;
+                    }
+                }
+            }
         }
     }
-    if route_parts.len() > req_parts.count() {
-        match_route = false;
-    }
     (match_route, params)
 }
 
@@ -248,4 +255,44 @@ mod tests {
             assert!(matches);
         }
     }
+
+    #[test]
+    fn test_matching_wildcard_routes() {
+        let route_paths = vec![
+            ("/*", ""),
+            ("*", ""),
+            ("*/", ""),
+            ("/*/", "/*/"),
+            ("path/*", "/path/more-path"),
+            ("path/*/", "/path/more-path"),
+            ("path/*/*/correct-path", "/path/more/other/correct-path"),
+            ("path/*/fixed-path", "/path/more/fixed-path"),
+            ("path/*/fixed-path/*/", "/path/more/fixed-path/anything/"),
+        ];
+        for (route, path) in route_paths {
+            let (matches, _) = compare_route_w_path_and_get_path_params(route, path);
+            assert!(matches);
+        }
+    }
+
+    #[test]
+    fn test_non_matching_wildcard_routes() {
+        let route_paths = vec![
+            ("path/*/fixed-path", "/wrong-root/more-path/fixed-path"),
+            ("path/*/fixed-path", "/path/more-path/wrong-end"),
+            ("path/*/", "wrong-path"),
+            (
+                "path/*/*/correct-path",
+                "/path/more-path/other-path/wrong-path",
+            ),
+            ("path/", "/*"),
+            ("path/", "path/*"),
+            ("path/more", "path/*"),
+            ("/experience/", "/experience/*"),
+        ];
+        for (route, path) in route_paths {
+            let (matches, _) = compare_route_w_path_and_get_path_params(route, path);
+            assert!(!matches);
+        }
+    }
 }
diff --git a/unchained/src/zip_longest.rs b/unchained/src/zip_longest.rs
new file mode 100644
index 0000000..67a9c3f
--- /dev/null
+++ b/unchained/src/zip_longest.rs
@@ -0,0 +1,46 @@
+//! Tools to handle zipping two iterators
+//! and continuing until both are exhausted.
+//! Inspired by [itertools::zip_longest](https://doc.servo.org/itertools/zip_longest/index.html)
+
+/// Struct where the next element is an option tuple
+/// with two optional elements.
+pub struct ZipLongestIter<T, U> {
+    a: T,
+    b: U,
+}
+
+impl<T, U> Iterator for ZipLongestIter<T, U>
+where
+    T: Iterator,
+    U: Iterator,
+{
+    type Item = (Option<T::Item>, Option<U::Item>);
+
+    /// Returns the next element in the iterator.
+    /// Returns Some as long as one element is available.
+    /// If both iterators are exhausted, returns None.
+    fn next(&mut self) -> Option<Self::Item> {
+        match (self.a.next(), self.b.next()) {
+            (None, None) => None,
+            (a, b) => Some((a, b)),
+        }
+    }
+}
+
+pub trait ZipLongest {
+    fn zip_longest<U>(self, other: U) -> ZipLongestIter<Self, U>
+    where
+        Self: Sized,
+        U: IntoIterator;
+}
+impl<T> ZipLongest for T
+where
+    T: Iterator,
+{
+    fn zip_longest<U>(self, other: U) -> ZipLongestIter<Self, U>
+    where
+        U: IntoIterator,
+    {
+        ZipLongestIter { a: self, b: other }
+    }
+}