From ace227bfa81b8135937c8d89e8741baf230075c1 Mon Sep 17 00:00:00 2001
From: Paul Delafosse <paul.delafosse@protonmail.com>
Date: Tue, 21 Nov 2023 08:35:03 +0100
Subject: [PATCH] Fix/function score (#260)

* fix: function score with no query serialisation

closes #257

* fix: fix field value factor serialization format
---
 .../queries/compound/function_score_query.rs  | 43 ++++++++++++++++++-
 .../queries/params/function_score_query.rs    |  5 ++-
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/src/search/queries/compound/function_score_query.rs b/src/search/queries/compound/function_score_query.rs
index 7008f6c..956f215 100644
--- a/src/search/queries/compound/function_score_query.rs
+++ b/src/search/queries/compound/function_score_query.rs
@@ -134,7 +134,7 @@ impl FunctionScoreQuery {
 
 impl ShouldSkip for FunctionScoreQuery {
     fn should_skip(&self) -> bool {
-        self.query.should_skip() || self.functions.should_skip()
+        self.functions.should_skip()
     }
 }
 
@@ -292,4 +292,45 @@ mod tests {
                     .filter(Query::term("type", "street")),
             );
     }
+
+    #[test]
+    fn should_not_skip_serializing_function_score_with_empty_query_gh_257() {
+        assert_serialize(
+            Query::bool().should(
+                Query::function_score()
+                    .function(
+                        Function::field_value_factor("weight")
+                            .factor(10.0)
+                            .missing(0.0)
+                            .modifier(FieldValueFactorModifier::Log1P)
+                            .weight(0.3),
+                    )
+                    .score_mode(FunctionScoreMode::Max)
+                    .boost_mode(FunctionBoostMode::Replace),
+            ),
+            json!( {
+                     "bool": {
+                       "should": [
+                         {
+                           "function_score": {
+                             "boost_mode": "replace",
+                             "functions": [
+                               {
+                                 "field_value_factor": {
+                                   "factor": 10.0,
+                                   "field": "weight",
+                                   "missing": 0.0,
+                                   "modifier": "log1p"
+                                 },
+                                 "weight": 0.3
+                               }
+                             ],
+                             "score_mode": "max"
+                           }
+                         }
+                       ]
+                    }
+            }),
+        )
+    }
 }
diff --git a/src/search/queries/params/function_score_query.rs b/src/search/queries/params/function_score_query.rs
index 14b75ad..63e849b 100644
--- a/src/search/queries/params/function_score_query.rs
+++ b/src/search/queries/params/function_score_query.rs
@@ -385,7 +385,7 @@ impl FieldValueFactor {
 ///
 /// Defaults to [none](FieldValueFactorModifier::None)
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize)]
-#[serde(rename_all = "snake_case")]
+#[serde(rename_all = "lowercase")]
 pub enum FieldValueFactorModifier {
     /// Do not apply any multiplier to the field value
     None,
@@ -475,6 +475,7 @@ pub struct Decay<T: Origin> {
 
     weight: Option<f32>,
 }
+
 #[derive(Debug, Clone, PartialEq)]
 struct DecayFieldInner<T: Origin> {
     field: String,
@@ -689,6 +690,6 @@ mod tests {
                     }
                 }
             }),
-        )
+        );
     }
 }