test: improve test coverage

Author: brianheineman

file_type/src/format/file_format.rs

@@ -105,11 +105,36 @@ mod tests {
     use super::*;
     use crate::format::{ByteSequence, PositionType};
 
+    #[test]
     fn test_format_id() {
         let source_type = SourceType::Custom;
         assert_eq!(source_type.format_id(1), "custom/1");
     }
 
+    #[test]
+    fn test_priority() {
+        assert_eq!(SourceType::Custom.priority(), 1);
+        assert_eq!(SourceType::Default.priority(), 0);
+        assert_eq!(SourceType::Httpd.priority(), 5);
+        assert_eq!(SourceType::Linguist.priority(), 4);
+        assert_eq!(SourceType::Pronom.priority(), 2);
+        assert_eq!(SourceType::Wikidata.priority(), 3);
+    }
+
+    #[test]
+    fn test_partial_cmp() {
+        assert_eq!(SourceType::Custom.partial_cmp(&SourceType::Custom), Some(Ordering::Equal));
+        assert_eq!(SourceType::Custom.partial_cmp(&SourceType::Default), Some(Ordering::Greater));
+        assert_eq!(SourceType::Default.partial_cmp(&SourceType::Custom), Some(Ordering::Less));
+    }
+
+    #[test]
+    fn test_cmp() {
+        assert_eq!(SourceType::Custom.cmp(&SourceType::Custom), Ordering::Equal);
+        assert_eq!(SourceType::Custom.cmp(&SourceType::Default), Ordering::Greater);
+        assert_eq!(SourceType::Default.cmp(&SourceType::Custom), Ordering::Less);
+    }
+
     #[test]
     fn test_to_source() {
         let file_format = FileFormat {