add tests

milli/src/index.rs

@@ -478,13 +478,44 @@ impl Index {
 }
 
 #[cfg(test)]
-mod tests {
+pub(crate) mod tests {
+    use std::ops::Deref;
+
     use heed::EnvOpenOptions;
     use maplit::hashmap;
+    use tempfile::TempDir;
 
     use crate::Index;
     use crate::update::{IndexDocuments, UpdateFormat};
 
+    pub(crate) struct TempIndex {
+        inner: Index,
+        _tempdir: TempDir,
+    }
+
+    impl Deref for TempIndex {
+        type Target = Index;
+
+        fn deref(&self) -> &Self::Target {
+            &self.inner
+        }
+    }
+
+    impl TempIndex {
+        /// Creates a temporary index, with a default `4096 * 100` size. This should be enough for
+        /// most tests.
+        pub fn new() -> Self {
+            let mut options = EnvOpenOptions::new();
+            options.map_size(100 * 4096);
+            let _tempdir = TempDir::new_in(".").unwrap();
+            let inner = Index::new(options, _tempdir.path()).unwrap();
+            Self {
+                inner,
+                _tempdir
+            }
+        }
+    }
+
     #[test]
     fn initial_fields_distribution() {
         let path = tempfile::tempdir().unwrap();

milli/src/search/distinct/facet_distinct.rs

@@ -6,7 +6,9 @@ use crate::heed_codec::facet::*;
 use crate::{facet::FacetType, DocumentId, FieldId, Index};
 use super::{Distinct, DocIter};
 
-/// A distinct implementer that is backed by facets. On each iteration, the facet values for the
+/// A distinct implementer that is backed by facets.
+///
+/// On each iteration, the facet values for the
 /// distinct attribute of the first document are retrieved. The document ids for these facet values
 /// are then retrieved and taken out of the the candidate and added to the excluded set. We take
 /// care to keep the document we are currently on, and remove it from the excluded list. The next
@@ -121,7 +123,7 @@ impl<'a> FacetDistinctIter<'a> {
     }
 
     /// Performs the next iteration of the facet distinct. This is a convenience method that is
-    /// called by the Iterator::next implementation that tranposes the result. It makes error
+    /// called by the Iterator::next implementation that transposes the result. It makes error
     /// handling easier.
     fn next_inner(&mut self) -> anyhow::Result<Option<DocumentId>> {
         // The first step is to remove all the excluded documents from our candidates
@@ -201,3 +203,36 @@ impl<'a> Distinct<'_> for FacetDistinct<'a> {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use std::collections::HashMap;
+
+    use super::*;
+    use super::super::test::{generate_index, validate_distinct_candidates};
+    use crate::facet::FacetType;
+
+    macro_rules! test_facet_distinct {
+        ($name:ident, $distinct:literal, $facet_type:expr) => {
+            #[test]
+            fn $name() {
+                use std::iter::FromIterator;
+
+                let facets = HashMap::from_iter(Some(($distinct.to_string(), $facet_type.to_string())));
+                let (index, fid, candidates) = generate_index($distinct, facets);
+                let txn = index.read_txn().unwrap();
+                let mut map_distinct = FacetDistinct::new(fid, &index, &txn, $facet_type);
+                let excluded = RoaringBitmap::new();
+                let mut iter = map_distinct.distinct(candidates.clone(), excluded);
+                let count = validate_distinct_candidates(iter.by_ref(), fid, &index);
+                let excluded = iter.into_excluded();
+                assert_eq!(count as u64 + excluded.len(), candidates.len());
+            }
+        };
+    }
+
+    test_facet_distinct!(test_string, "txt", FacetType::String);
+    test_facet_distinct!(test_strings, "txts", FacetType::String);
+    test_facet_distinct!(test_int, "cat-int", FacetType::Integer);
+    test_facet_distinct!(test_ints, "cat-ints", FacetType::Integer);
+}

milli/src/search/distinct/map_distinct.rs

@@ -6,7 +6,9 @@ use serde_json::Value;
 use super::{Distinct, DocIter};
 use crate::{DocumentId, FieldId, Index};
 
-/// A distinct implementer that is backed by an `HashMap`. Each time a document is seen, the value
+/// A distinct implementer that is backed by an `HashMap`.
+///
+/// Each time a document is seen, the value
 /// for its distinct field is added to the map. If the map already contains an entry for this
 /// value, then the document is filtered out, and is added to the excluded set.
 pub struct MapDistinct<'a> {
@@ -38,7 +40,7 @@ pub struct MapDistinctIter<'a, 'b> {
 
 impl<'a, 'b> MapDistinctIter<'a, 'b> {
     /// Performs the next iteration of the mafacetp distinct. This is a convenience method that is
-    /// called by the Iterator::next implementation that tranposes the result. It makes error
+    /// called by the Iterator::next implementation that transposes the result. It makes error
     /// handling easier.
     fn next_inner(&mut self) -> anyhow::Result<Option<DocumentId>> {
         let map = &mut self.map;
@@ -105,3 +107,32 @@ impl<'a, 'b> Distinct<'b> for MapDistinct<'a> {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use std::collections::HashMap;
+
+    use super::*;
+    use super::super::test::{generate_index, validate_distinct_candidates};
+
+    macro_rules! test_map_distinct {
+        ($name:ident, $distinct:literal) => {
+            #[test]
+            fn $name() {
+                let (index, fid, candidates) = generate_index($distinct, HashMap::new());
+                let txn = index.read_txn().unwrap();
+                let mut map_distinct = MapDistinct::new(fid, &index, &txn);
+                let excluded = RoaringBitmap::new();
+                let mut iter = map_distinct.distinct(candidates.clone(), excluded);
+                let count = validate_distinct_candidates(iter.by_ref(), fid, &index);
+                let excluded = iter.into_excluded();
+                assert_eq!(count as u64 + excluded.len(), candidates.len());
+            }
+        };
+    }
+
+    test_map_distinct!(test_string, "txt");
+    test_map_distinct!(test_strings, "txts");
+    test_map_distinct!(test_int, "cat-int");
+    test_map_distinct!(test_ints, "cat-ints");
+}

milli/src/search/distinct/mod.rs

@@ -4,10 +4,10 @@ mod noop_distinct;
 
 use roaring::RoaringBitmap;
 
+use crate::DocumentId;
 pub use facet_distinct::FacetDistinct;
 pub use map_distinct::MapDistinct;
 pub use noop_distinct::NoopDistinct;
-use crate::DocumentId;
 
 /// A trait implemented by document interators that are returned by calls to `Distinct::distinct`.
 /// It provides a way to get back the ownership to the excluded set.
@@ -25,3 +25,120 @@ pub trait Distinct<'a> {
 
     fn distinct(&'a mut self, candidates: RoaringBitmap, excluded: RoaringBitmap) -> Self::Iter;
 }
+
+#[cfg(test)]
+mod test {
+    use std::collections::{HashMap, HashSet};
+
+    use once_cell::sync::Lazy;
+    use rand::{seq::SliceRandom, Rng};
+    use roaring::RoaringBitmap;
+    use serde_json::{json, Value};
+
+    use crate::index::{Index, tests::TempIndex};
+    use crate::update::{IndexDocumentsMethod, UpdateBuilder, UpdateFormat};
+    use crate::{BEU32, FieldId, DocumentId};
+
+    static JSON: Lazy<Value> = Lazy::new(generate_json);
+
+    fn generate_json() -> Value {
+        let mut rng = rand::thread_rng();
+        let num_docs = rng.gen_range(10..30);
+
+        let mut documents = Vec::new();
+
+        let txts = ["toto", "titi", "tata"];
+        let cats = (1..10).map(|i| i.to_string()).collect::<Vec<_>>();
+        let cat_ints = (1..10).collect::<Vec<_>>();
+
+        for i in 0..num_docs {
+            let txt = txts.choose(&mut rng).unwrap();
+            let mut sample_txts = cats.clone();
+            sample_txts.shuffle(&mut rng);
+
+            let mut sample_ints = cat_ints.clone();
+            sample_ints.shuffle(&mut rng);
+
+            let doc = json!({
+                "id": i,
+                "txt": txt,
+                "cat-int": rng.gen_range(0..3),
+                "txts": sample_txts[..(rng.gen_range(0..3))],
+                "cat-ints": sample_ints[..(rng.gen_range(0..3))],
+            });
+            documents.push(doc);
+        }
+
+        Value::Array(documents)
+    }
+
+    /// Returns a temporary index populated with random test documents, the FieldId for the
+    /// distinct attribute, and the RoaringBitmap with the document ids.
+    pub(crate) fn generate_index(distinct: &str, facets: HashMap<String, String>) -> (TempIndex, FieldId, RoaringBitmap) {
+        let index = TempIndex::new();
+        let mut txn = index.write_txn().unwrap();
+
+        // set distinct and faceted attributes for the index.
+        let builder = UpdateBuilder::new(0);
+        let mut update = builder.settings(&mut txn, &index);
+        update.set_distinct_attribute(distinct.to_string());
+        if !facets.is_empty() {
+            update.set_faceted_fields(facets)
+        }
+        update.execute(|_, _| ()).unwrap();
+
+        // add documents to the index
+        let builder = UpdateBuilder::new(1);
+        let mut addition = builder.index_documents(&mut txn, &index);
+
+        addition.index_documents_method(IndexDocumentsMethod::ReplaceDocuments);
+        addition.update_format(UpdateFormat::Json);
+
+        addition
+            .execute(JSON.to_string().as_bytes(), |_, _| ())
+            .unwrap();
+
+        let fields_map = index.fields_ids_map(&txn).unwrap();
+        let fid = fields_map.id(&distinct).unwrap();
+
+        let map = (0..JSON.as_array().unwrap().len() as u32).collect();
+
+        txn.commit().unwrap();
+
+        (index, fid, map)
+    }
+
+
+    /// Checks that all the candidates are distinct, and returns the candidates number.
+    pub(crate) fn validate_distinct_candidates(
+        candidates: impl Iterator<Item=anyhow::Result<DocumentId>>,
+        distinct: FieldId,
+        index: &Index,
+        ) -> usize {
+        fn test(seen: &mut HashSet<String>, value: &Value) {
+            match value {
+                Value::Null | Value::Object(_) | Value::Bool(_) => (),
+                Value::Number(_) | Value::String(_) => {
+                    let s = value.to_string();
+                    assert!(seen.insert(s));
+                }
+                Value::Array(values) => {values.into_iter().for_each(|value| test(seen, value))}
+            }
+        }
+
+        let mut seen = HashSet::<String>::new();
+
+        let txn = index.read_txn().unwrap();
+        let mut count = 0;
+        for candidate in candidates {
+            count += 1;
+            let candidate = candidate.unwrap();
+            let id = BEU32::new(candidate);
+            let document = index.documents.get(&txn, &id).unwrap().unwrap();
+            let value = document.get(distinct).unwrap();
+            let value = serde_json::from_slice(value).unwrap();
+            test(&mut seen, &value);
+        }
+        count
+    }
+}

milli/src/search/distinct/noop_distinct.rs

@@ -3,8 +3,8 @@ use roaring::{RoaringBitmap, bitmap::IntoIter};
 use crate::DocumentId;
 use super::{DocIter, Distinct};
 
-/// A distinct implementer that does not perform any distinct, and simply returns an iterator to
-/// the candidates.
+/// A distinct implementer that does not perform any distinct,
+/// and simply returns an iterator to the candidates.
 pub struct NoopDistinct;
 
 pub struct NoopDistinctIter {
@@ -36,3 +36,22 @@ impl Distinct<'_> for NoopDistinct {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_noop() {
+        let candidates = (1..10).collect();
+        let excluded = RoaringBitmap::new();
+        let mut iter = NoopDistinct.distinct(candidates, excluded);
+        assert_eq!(
+            iter.by_ref().map(Result::unwrap).collect::<Vec<_>>(),
+            (1..10).collect::<Vec<_>>()
+        );
+
+        let excluded = iter.into_excluded();
+        assert!(excluded.is_empty());
+    }
+}