Filter tests (estk#357)

* chore: add filter tests

Cargo.toml

@@ -88,6 +88,7 @@ streaming-stats = "0.2.3"
 humantime = "2.1"
 tempfile = "3.8"
 mock_instant = "0.3"
+serde_test = "1.0.176"
 
 [[example]]
 name = "json_logger"

src/filter/mod.rs

@@ -31,6 +31,7 @@ impl Deserializable for dyn Filter {
     }
 }
 
+#[derive(PartialEq, Debug)]
 /// The response returned by a filter.
 pub enum Response {
     /// Accept the log event.
@@ -78,3 +79,44 @@ impl<'de> de::Deserialize<'de> for FilterConfig {
         })
     }
 }
+
+#[cfg(test)]
+mod test {
+    #[cfg(feature = "config_parsing")]
+    use super::*;
+    #[cfg(feature = "config_parsing")]
+    use serde_test::{assert_de_tokens, assert_de_tokens_error, Token};
+
+    #[test]
+    #[cfg(feature = "config_parsing")]
+    fn test_cfg_deserializer() {
+        let filter = FilterConfig {
+            kind: "threshold".to_owned(),
+            config: Value::Map({
+                let mut map = BTreeMap::new();
+                map.insert(
+                    Value::String("level".to_owned()),
+                    Value::String("error".to_owned()),
+                );
+                map
+            }),
+        };
+
+        let mut cfg = vec![
+            Token::Struct {
+                name: "FilterConfig",
+                len: 2,
+            },
+            Token::Str("kind"),
+            Token::Str("threshold"),
+            Token::Str("level"),
+            Token::Str("error"),
+            Token::StructEnd,
+        ];
+
+        assert_de_tokens(&filter, &cfg);
+
+        cfg[1] = Token::Str("knd");
+        assert_de_tokens_error::<FilterConfig>(&cfg, "missing field `kind`");
+    }
+}

src/filter/threshold.rs

@@ -66,3 +66,98 @@ impl Deserialize for ThresholdFilterDeserializer {
         Ok(Box::new(ThresholdFilter::new(config.level)))
     }
 }
+
+#[cfg(test)]
+mod test {
+    use log::{Level, LevelFilter, Record};
+
+    use super::*;
+
+    #[cfg(feature = "config_parsing")]
+    use crate::config::Deserializers;
+
+    #[cfg(feature = "config_parsing")]
+    use serde_test::{assert_de_tokens, assert_de_tokens_error, Token};
+
+    #[test]
+    #[cfg(feature = "config_parsing")]
+    fn test_cfg_deserialize() {
+        let filter_cfg = ThresholdFilterConfig {
+            level: LevelFilter::Off,
+        };
+
+        let mut cfg = vec![
+            Token::Struct {
+                name: "ThresholdFilterConfig",
+                len: 1,
+            },
+            Token::Str("level"),
+            Token::Enum {
+                name: "LevelFilter",
+            },
+            Token::Str("Off"),
+            Token::Unit,
+            Token::StructEnd,
+        ];
+
+        assert_de_tokens(&filter_cfg, &cfg);
+
+        cfg[1] = Token::Str("leel");
+        assert_de_tokens_error::<ThresholdFilterConfig>(&cfg, "missing field `level`");
+
+        cfg[1] = Token::Str("level");
+        cfg[3] = Token::Str("On");
+        cfg.remove(4); // No Unit on this one as the Option is invalid
+        assert_de_tokens_error::<ThresholdFilterConfig>(
+            &cfg,
+            "unknown variant `On`, expected one of `OFF`, `ERROR`, `WARN`, `INFO`, `DEBUG`, `TRACE`",
+        );
+    }
+
+    #[test]
+    fn test_filter_new_vs_struct() {
+        assert_eq!(
+            ThresholdFilter::new(LevelFilter::Info),
+            ThresholdFilter {
+                level: LevelFilter::Info
+            }
+        );
+    }
+
+    #[test]
+    fn test_threshold_filter() {
+        let thres = ThresholdFilter::new(LevelFilter::Info);
+        let debug_record = Record::builder()
+            .level(Level::Debug)
+            .args(format_args!("the message"))
+            .module_path(Some("path"))
+            .file(Some("file"))
+            .line(Some(132))
+            .build();
+
+        assert_eq!(thres.filter(&debug_record), Response::Reject);
+
+        let error_record = Record::builder()
+            .level(Level::Error)
+            .args(format_args!("the message"))
+            .module_path(Some("path"))
+            .file(Some("file"))
+            .line(Some(132))
+            .build();
+
+        assert_eq!(thres.filter(&error_record), Response::Neutral);
+    }
+
+    #[test]
+    #[cfg(feature = "config_parsing")]
+    fn test_cfg_deserializer() {
+        let filter_cfg = ThresholdFilterConfig {
+            level: LevelFilter::Off,
+        };
+
+        let deserializer = ThresholdFilterDeserializer;
+
+        let res = deserializer.deserialize(filter_cfg, &Deserializers::default());
+        assert!(res.is_ok());
+    }
+}