test: add test for flank_rate_of_spread

src/fbp/ros/flank_rate_of_spread.rs

@@ -23,3 +23,32 @@
 pub fn flank_rate_of_spread(ros: f64, bros: f64, lb: f64) -> f64 {
     (ros + bros) / lb / 2.
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_util::precision_f64;
+
+    #[derive(Debug, serde::Deserialize)]
+    struct TestRow {
+        ros: f64,
+        bros: f64,
+        lb: f64,
+        fros: f64,
+    }
+
+    #[test]
+    fn test_flank_rate_of_spread() -> Result<(), Box<dyn std::error::Error>> {
+        let fixture = std::fs::File::open("./tests/fixtures/flank_rate_of_spread.csv")?;
+        let mut rdr = csv::Reader::from_reader(fixture);
+
+        for result in rdr.deserialize() {
+            let record: TestRow = result?;
+            let fros = flank_rate_of_spread(record.ros, record.bros, record.lb);
+
+            assert_eq!(precision_f64(fros, 4), record.fros);
+        }
+
+        Ok(())
+    }
+}