refactor: rework uri_encode to limit allocation

add add some related tests.

catched from clippy lint `format_collect`
message: use of `format!` to build up a string from an iterator
  --> src/api/common/encoding.rs:12:17
   |
12 |                   let value = format!("{}", c)
   |  _____________________________^
13 | |                     .bytes()
14 | |                     .map(|b| format!("%{:02X}", b))
15 | |                     .collect::<String>();
   | |________________________________________^
   |
help: call `fold` instead
  --> src/api/common/encoding.rs:14:7
   |
14 |                     .map(|b| format!("%{:02X}", b))
   |                      ^^^
help: ... and use the `write!` macro here
  --> src/api/common/encoding.rs:14:15
   |
14 |                     .map(|b| format!("%{:02X}", b))
   |                              ^^^^^^^^^^^^^^^^^^^^^
   = note: this can be written more efficiently by appending to a `String` directly
   = help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.93.0/index.html#format_collect

Cargo.toml

@@ -183,6 +183,7 @@ strip = "debuginfo"
 [workspace.lints.clippy]
 # pedantic lints configuration
 doc_markdown = "warn"
+format_collect = "warn"
 manual_midpoint = "warn"
 semicolon_if_nothing_returned = "warn"
 unnecessary_semicolon = "warn"

src/api/common/encoding.rs

@@ -1,5 +1,7 @@
 //! Module containing various helpers for encoding
 
+use std::fmt::Write as _;
+
 /// Encode &str for use in a URI
 pub fn uri_encode(string: &str, encode_slash: bool) -> String {
 	let mut result = String::with_capacity(string.len() * 2);
@@ -9,14 +11,98 @@ pub fn uri_encode(string: &str, encode_slash: bool) -> String {
 			'/' if encode_slash => result.push_str("%2F"),
 			'/' if !encode_slash => result.push('/'),
 			_ => {
-				result.push_str(
-					&format!("{}", c)
-						.bytes()
-						.map(|b| format!("%{:02X}", b))
-						.collect::<String>(),
-				);
+				let mut buf = [0_u8; 4];
+				let str = c.encode_utf8(&mut buf);
+				for b in str.bytes() {
+					write!(&mut result, "%{:02X}", b).unwrap();
+				}
 			}
 		}
 	}
 	result
 }
+
+#[cfg(test)]
+mod tests {
+	use crate::encoding::uri_encode;
+
+	#[test]
+	fn test_uri_encode() {
+		let url1_encoded = uri_encode(
+			"https://garagehq.deuxfleurs.fr/documentation/reference-manual/features/",
+			true,
+		);
+		assert_eq!(
+			&url1_encoded,
+			"https%3A%2F%2Fgaragehq.deuxfleurs.fr%2Fdocumentation%2Freference-manual%2Ffeatures%2F"
+		);
+
+		let url2_encoded = uri_encode(
+			"https://garagehq.deuxfleurs.fr/blog/2025-06-garage-v2/",
+			true,
+		);
+		assert_eq!(
+			&url2_encoded,
+			"https%3A%2F%2Fgaragehq.deuxfleurs.fr%2Fblog%2F2025-06-garage-v2%2F"
+		);
+
+		let url3_encoded = uri_encode(
+			"https://garagehq.deuxfleurs.fr/blog/2025-06-hé_les_gens/",
+			true,
+		);
+		assert_eq!(
+			&url3_encoded,
+			"https%3A%2F%2Fgaragehq.deuxfleurs.fr%2Fblog%2F2025-06-h%C3%A9_les_gens%2F"
+		);
+
+		let url4_encoded = uri_encode("/home/local user/Documents/personnel/à_blog.md", true);
+		assert_eq!(
+			&url4_encoded,
+			"%2Fhome%2Flocal%20user%2FDocuments%2Fpersonnel%2F%C3%A0_blog.md"
+		);
+	}
+
+	#[test]
+	fn test_uri_encode_without_slash() {
+		let url1_encoded = uri_encode(
+			"https://garagehq.deuxfleurs.fr/documentation/reference-manual/features/",
+			false,
+		);
+		assert_eq!(
+			&url1_encoded,
+			"https%3A//garagehq.deuxfleurs.fr/documentation/reference-manual/features/"
+		);
+
+		let url2_encoded = uri_encode(
+			"https://garagehq.deuxfleurs.fr/blog/2025-06-garage-v2/",
+			false,
+		);
+		assert_eq!(
+			&url2_encoded,
+			"https%3A//garagehq.deuxfleurs.fr/blog/2025-06-garage-v2/"
+		);
+
+		let url3_encoded = uri_encode(
+			"https://garagehq.deuxfleurs.fr/blog/2025-06-hé_les_gens/",
+			false,
+		);
+		assert_eq!(
+			&url3_encoded,
+			"https%3A//garagehq.deuxfleurs.fr/blog/2025-06-h%C3%A9_les_gens/"
+		);
+		let url4_encoded = uri_encode("/home/local user/Documents/personnel/à_blog.md", false);
+		assert_eq!(
+			&url4_encoded,
+			"/home/local%20user/Documents/personnel/%C3%A0_blog.md"
+		);
+	}
+
+	#[test]
+	fn test_uri_encode_most_than_double_size() {
+		let url_encoded = uri_encode("/home/ùàé ç/çaèù/à_êô.md", true);
+		assert_eq!(
+			&url_encoded,
+			"%2Fhome%2F%C3%B9%C3%A0%C3%A9%20%C3%A7%2F%C3%A7a%C3%A8%C3%B9%2F%C3%A0_%C3%AA%C3%B4.md"
+		);
+	}
+}