Add tests for Color::parse

src/theme/color.rs

@@ -155,14 +155,14 @@ impl Color {
     /// * `"#123456"` becomes `Color::Rgb(0x12, 0x34, 0x56)`
     pub fn parse(value: &str) -> Option<Self> {
         Some(match value {
-            "black" => Color::Dark(BaseColor::Black),
-            "red" => Color::Dark(BaseColor::Red),
-            "green" => Color::Dark(BaseColor::Green),
-            "yellow" => Color::Dark(BaseColor::Yellow),
-            "blue" => Color::Dark(BaseColor::Blue),
-            "magenta" => Color::Dark(BaseColor::Magenta),
-            "cyan" => Color::Dark(BaseColor::Cyan),
-            "white" => Color::Dark(BaseColor::White),
+            "dark black" | "black" => Color::Dark(BaseColor::Black),
+            "dark red" | "red" => Color::Dark(BaseColor::Red),
+            "dark green" | "green" => Color::Dark(BaseColor::Green),
+            "dark yellow" | "yellow" => Color::Dark(BaseColor::Yellow),
+            "dark blue" | "blue" => Color::Dark(BaseColor::Blue),
+            "dark magenta" | "magenta" => Color::Dark(BaseColor::Magenta),
+            "dark cyan" | "cyan" => Color::Dark(BaseColor::Cyan),
+            "dark white" | "white" => Color::Dark(BaseColor::White),
             "light black" => Color::Light(BaseColor::Black),
             "light red" => Color::Light(BaseColor::Red),
             "light green" => Color::Light(BaseColor::Green),
@@ -172,73 +172,136 @@ impl Color {
             "light cyan" => Color::Light(BaseColor::Cyan),
             "light white" => Color::Light(BaseColor::White),
             "default" => Color::TerminalDefault,
-            value => return Color::parse_special(value),
+            value => {
+                return parse_special(value).or_else(|| {
+                    log::warn!("Could not parse color `{}`.", value);
+                    None
+                })
+            }
         })
     }
+}
 
-    fn parse_special(value: &str) -> Option<Color> {
-        if value.starts_with('#') {
-            let value = &value[1..];
-            // Compute per-color length, and amplitude
-            let (l, multiplier) = match value.len() {
-                6 => (2, 1),
-                3 => (1, 17),
-                _ => panic!("Cannot parse color: {}", value),
-            };
-            let r = load_hex(&value[0..l]) * multiplier;
-            let g = load_hex(&value[l..2 * l]) * multiplier;
-            let b = load_hex(&value[2 * l..3 * l]) * multiplier;
+fn parse_special(value: &str) -> Option<Color> {
+    if value.starts_with('#') {
+        parse_hex(&value[1..])
+    } else if value.starts_with("0x") {
+        parse_hex(&value[2..])
+    } else if value.len() == 6 {
+        parse_hex(value)
+    } else if value.len() == 3 {
+        // RGB values between 0 and 5 maybe?
+        // Like 050 for green
+        let rgb: Vec<_> =
+            value.chars().map(|c| c as i16 - '0' as i16).collect();
 
-            Some(Color::Rgb(r as u8, g as u8, b as u8))
-        } else if value.len() == 3 {
-            // RGB values between 0 and 5 maybe?
-            // Like 050 for green
-            let rgb: Vec<_> =
-                value.chars().map(|c| c as i16 - '0' as i16).collect();
-
-            assert_eq!(rgb.len(), 3);
-            if rgb.iter().all(|&i| i >= 0 && i < 6) {
-                Some(Color::RgbLowRes(
-                    rgb[0] as u8,
-                    rgb[1] as u8,
-                    rgb[2] as u8,
-                ))
-            } else {
-                None
-            }
+        assert_eq!(rgb.len(), 3);
+        if rgb.iter().all(|&i| i >= 0 && i < 6) {
+            Some(Color::RgbLowRes(rgb[0] as u8, rgb[1] as u8, rgb[2] as u8))
         } else {
             None
         }
+    } else {
+        None
     }
 }
 
+fn parse_hex(value: &str) -> Option<Color> {
+    // Compute per-color length, and amplitude
+    let (l, multiplier) = match value.len() {
+        6 => (2, 1),
+        3 => (1, 17),
+        _ => return None,
+    };
+    let r = load_hex(&value[0..l]) * multiplier;
+    let g = load_hex(&value[l..2 * l]) * multiplier;
+    let b = load_hex(&value[2 * l..3 * l]) * multiplier;
+
+    Some(Color::Rgb(r as u8, g as u8, b as u8))
+}
+
 /// Loads a hexadecimal code
 fn load_hex(s: &str) -> u16 {
-    let mut sum = 0;
-    for c in s.chars() {
-        sum *= 16;
-        sum += match c {
-            n @ '0'..='9' => n as i16 - '0' as i16,
-            n @ 'a'..='f' => n as i16 - 'a' as i16 + 10,
-            n @ 'A'..='F' => n as i16 - 'A' as i16 + 10,
-            _ => 0,
-        };
-    }
-
-    sum as u16
+    s.chars()
+        .rev()
+        .filter_map(|c| {
+            Some(match c {
+                '0'..='9' => c as u16 - '0' as u16,
+                'a'..='f' => c as u16 - 'a' as u16 + 10,
+                'A'..='F' => c as u16 - 'A' as u16 + 10,
+                other => {
+                    log::warn!(
+                        "Invalid character `{}` in hexadecimal value `{}`.",
+                        other,
+                        s
+                    );
+                    return None;
+                }
+            })
+        })
+        .enumerate()
+        .map(|(i, c)| c * 16u16.pow(i as u32))
+        .sum()
 }
 
 #[cfg(test)]
 mod tests {
+    use super::Color;
 
     #[test]
     fn test_256_colors() {
         // Make sure Color::from_256colors never panics
-        use super::Color;
 
-        // TODO: use inclusive range when it gets stable
-        for i in 0..256u16 {
-            Color::from_256colors(i as u8);
+        for i in 0..=255u8 {
+            Color::from_256colors(i);
+        }
+    }
+
+    #[test]
+    fn test_parse() {
+        assert_eq!(Color::parse("#fff"), Some(Color::Rgb(255, 255, 255)));
+
+        assert_eq!(
+            Color::parse("#abcdef"),
+            Some(Color::Rgb(0xab, 0xcd, 0xef))
+        );
+
+        assert_eq!(
+            Color::parse("0xFEDCBA"),
+            Some(Color::Rgb(0xfe, 0xdc, 0xba))
+        );
+    }
+
+    #[test]
+    fn test_low_res() {
+        // Make sure Color::low_res always works with valid ranges.
+        for r in 0..=5 {
+            for g in 0..=5 {
+                for b in 0..=5 {
+                    assert!(
+                        Color::low_res(r, g, b).is_some(),
+                        "Could not create lowres color {}:{}:{}",
+                        r,
+                        g,
+                        b,
+                    );
+                }
+            }
+        }
+
+        for r in 6..=10 {
+            for g in 6..=10 {
+                for b in 6..=10 {
+                    assert_eq!(
+                        Color::low_res(r, g, b),
+                        None,
+                        "Created invalid lowres color {}:{}:{}",
+                        r,
+                        g,
+                        b,
+                    );
+                }
+            }
         }
     }
 }