refactor(http): Use query string helper (#2348)

CODE_OF_CONDUCT.md

@@ -3,7 +3,7 @@
 We as members, contributors, and leaders pledge to make participation in our
 community a harassment-free experience for everyone, regardless of age, body
 size, visible or invisible disability, ethnicity, sex characteristics, gender
-identity and expression, level of experience, education, socio-economic status,
+identity and expression, level of experience, education, socioeconomic status,
 nationality, personal appearance, race, caste, color, religion, or sexual
 identity and orientation.
 

twilight-http/src/lib.rs

@@ -14,6 +14,7 @@ pub mod response;
 pub mod routing;
 
 mod json;
+mod query_formatter;
 
 /// Discord API version used by this crate.
 pub const API_VERSION: u8 = 10;

twilight-http/src/query_formatter.rs

@@ -0,0 +1,126 @@
+use std::fmt::{Display, Formatter, Write};
+
+/// A helper struct to write query paramseters to a formatter.
+pub struct QueryStringFormatter<'w1, 'w2> {
+    formatter: &'w1 mut Formatter<'w2>,
+    is_first: bool,
+}
+
+impl<'w1, 'w2> QueryStringFormatter<'w1, 'w2> {
+    pub fn new(formatter: &'w1 mut Formatter<'w2>) -> Self {
+        Self {
+            formatter,
+            is_first: true,
+        }
+    }
+
+    /// Writes a query parameter to the formatter.
+    ///
+    /// # Errors
+    ///
+    /// This returns a [`std::fmt::Error`] if the formatter returns an error.
+    pub fn write_param(&mut self, key: &str, value: &impl Display) -> std::fmt::Result {
+        if self.is_first {
+            self.formatter.write_char('?')?;
+            self.is_first = false;
+        } else {
+            self.formatter.write_char('&')?;
+        }
+
+        self.formatter.write_str(key)?;
+        self.formatter.write_char('=')?;
+        Display::fmt(value, self.formatter)
+    }
+
+    /// Writes a query parameter to the formatter.
+    ///
+    /// # Errors
+    ///
+    /// This returns a [`std::fmt::Error`] if the formatter returns an error.
+    pub fn write_opt_param(&mut self, key: &str, value: Option<&impl Display>) -> std::fmt::Result {
+        if let Some(value) = value {
+            self.write_param(key, value)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+/// Provides a display implementation for serializing iterable objects into
+/// query params.
+#[derive(Debug)]
+pub struct QueryArray<T>(pub T);
+
+impl<T, U> Display for QueryArray<T>
+where
+    T: IntoIterator<Item = U> + Clone,
+    U: Display,
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut iter = self.0.clone().into_iter().peekable();
+
+        while let Some(item) = iter.next() {
+            Display::fmt(&item, f)?;
+            if iter.peek().is_some() {
+                f.write_str(",")?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    struct Test {
+        a: Option<u32>,
+        b: Option<String>,
+    }
+
+    impl Display for Test {
+        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+            let mut writer = QueryStringFormatter::new(f);
+            writer.write_opt_param("a", self.a.as_ref())?;
+            writer.write_opt_param("b", self.b.as_ref())
+        }
+    }
+
+    #[test]
+    fn test_query_string_formatter_filled() {
+        let test = Test {
+            a: Some(1),
+            b: Some("hello".to_string()),
+        };
+
+        assert_eq!(test.to_string(), "?a=1&b=hello");
+    }
+
+    #[test]
+    fn test_query_string_formatter_empty() {
+        let test = Test { a: None, b: None };
+
+        assert_eq!(test.to_string(), "");
+    }
+
+    #[test]
+    fn test_query_string_formatter_single() {
+        let test = Test {
+            a: Some(1),
+            b: None,
+        };
+
+        assert_eq!(test.to_string(), "?a=1");
+    }
+
+    #[test]
+    fn test_query_array() {
+        let query_array = QueryArray([1, 2, 3]);
+        assert_eq!(query_array.to_string(), "1,2,3");
+
+        let params = vec!["a", "b", "c"];
+        let query_array = QueryArray(&params);
+        assert_eq!(query_array.to_string(), "a,b,c");
+    }
+}