From 399eec5c0101780f74b9794957865c3fe8b3d519 Mon Sep 17 00:00:00 2001
From: Kerollmops <clement@meilisearch.com>
Date: Wed, 15 Jun 2022 14:35:19 +0200
Subject: [PATCH] Fix the indexation tests

---
 benchmarks/benches/indexing.rs               | 110 ++++++----
 cli/src/main.rs                              |   7 +-
 http-ui/src/main.rs                          |   6 +-
 milli/src/index.rs                           |  25 ++-
 milli/src/search/distinct/mod.rs             |   5 +-
 milli/src/search/facet/filter.rs             |   5 +-
 milli/src/update/clear_documents.rs          |   5 +-
 milli/src/update/delete_documents.rs         |  18 +-
 milli/src/update/index_documents/mod.rs      | 205 +++++++++++--------
 milli/src/update/index_documents/validate.rs |   1 +
 milli/src/update/settings.rs                 |  70 ++++---
 milli/tests/search/facet_distribution.rs     |   6 +-
 milli/tests/search/mod.rs                    |   6 +-
 milli/tests/search/query_criteria.rs         |   6 +-
 milli/tests/search/typo_tolerance.rs         |   7 +-
 15 files changed, 288 insertions(+), 194 deletions(-)

diff --git a/benchmarks/benches/indexing.rs b/benchmarks/benches/indexing.rs
index 3ae0a1a84..1b501b21a 100644
--- a/benchmarks/benches/indexing.rs
+++ b/benchmarks/benches/indexing.rs
@@ -132,12 +132,13 @@ fn indexing_songs_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -223,11 +224,12 @@ fn deleting_songs_in_batches_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -279,11 +281,12 @@ fn indexing_songs_in_three_batches_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS_1_2, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -294,19 +297,21 @@ fn indexing_songs_in_three_batches_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS_3_4, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS_4_4, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -339,13 +344,14 @@ fn indexing_songs_without_faceted_numbers(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS, "csv");
 
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -377,12 +383,13 @@ fn indexing_songs_without_faceted_fields(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::SMOL_SONGS, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -415,12 +422,13 @@ fn indexing_wiki(c: &mut Criterion) {
                 let indexing_config =
                     IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::SMOL_WIKI_ARTICLES, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -507,11 +515,12 @@ fn deleting_wiki_in_batches_default(c: &mut Criterion) {
                 let mut wtxn = index.write_txn().unwrap();
                 let indexing_config =
                     IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::SMOL_WIKI_ARTICLES, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -564,12 +573,13 @@ fn indexing_wiki_in_three_batches(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config =
                     IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents =
                     utils::documents_from(datasets_paths::SMOL_WIKI_ARTICLES_1_2, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -581,24 +591,26 @@ fn indexing_wiki_in_three_batches(c: &mut Criterion) {
                 let indexing_config =
                     IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents =
                     utils::documents_from(datasets_paths::SMOL_WIKI_ARTICLES_3_4, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 let indexing_config =
                     IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents =
                     utils::documents_from(datasets_paths::SMOL_WIKI_ARTICLES_4_4, "csv");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -631,12 +643,13 @@ fn indexing_movies_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::MOVIES, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -720,11 +733,12 @@ fn deleting_movies_in_batches_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::MOVIES, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -775,12 +789,13 @@ fn indexing_movies_in_three_batches(c: &mut Criterion) {
                 // as we don't care about the time it takes.
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::MOVIES_1_2, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -791,21 +806,23 @@ fn indexing_movies_in_three_batches(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::MOVIES_3_4, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::MOVIES_4_4, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -861,12 +878,13 @@ fn indexing_nested_movies_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::NESTED_MOVIES, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -922,11 +940,12 @@ fn deleting_nested_movies_in_batches_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::NESTED_MOVIES, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -984,12 +1003,13 @@ fn indexing_nested_movies_without_faceted_fields(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::NESTED_MOVIES, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
@@ -1021,12 +1041,13 @@ fn indexing_geo(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let indexing_config = IndexDocumentsConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
 
                 let documents = utils::documents_from(datasets_paths::SMOL_ALL_COUNTRIES, "jsonl");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
 
                 wtxn.commit().unwrap();
@@ -1113,11 +1134,12 @@ fn deleting_geo_in_batches_default(c: &mut Criterion) {
                 let config = IndexerConfig::default();
                 let mut wtxn = index.write_txn().unwrap();
                 let indexing_config = IndexDocumentsConfig::default();
-                let mut builder =
+                let builder =
                     IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ())
                         .unwrap();
                 let documents = utils::documents_from(datasets_paths::SMOL_ALL_COUNTRIES, "json");
-                builder.add_documents(documents).unwrap();
+                let (builder, user_error) = builder.add_documents(documents).unwrap();
+                user_error.unwrap();
                 builder.execute().unwrap();
                 wtxn.commit().unwrap();
 
diff --git a/cli/src/main.rs b/cli/src/main.rs
index db4ca91ab..0d197af17 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -255,7 +255,7 @@ impl Performer for DocumentAddition {
             let bar = progesses.add(bar);
             bars.push(bar);
         }
-        let mut addition = milli::update::IndexDocuments::new(
+        let addition = milli::update::IndexDocuments::new(
             &mut txn,
             &index,
             &config,
@@ -263,7 +263,10 @@ impl Performer for DocumentAddition {
             |step| indexing_callback(step, &bars),
         )
         .unwrap();
-        addition.add_documents(reader)?;
+        let (addition, user_error) = addition.add_documents(reader)?;
+        if let Err(error) = user_error {
+            return Err(error.into());
+        }
 
         std::thread::spawn(move || {
             progesses.join().unwrap();
diff --git a/http-ui/src/main.rs b/http-ui/src/main.rs
index 8167076c6..117aa31e8 100644
--- a/http-ui/src/main.rs
+++ b/http-ui/src/main.rs
@@ -374,7 +374,7 @@ async fn main() -> anyhow::Result<()> {
                         });
                     };
 
-                    let mut builder = milli::update::IndexDocuments::new(
+                    let builder = milli::update::IndexDocuments::new(
                         &mut wtxn,
                         &index_cloned,
                         GLOBAL_CONFIG.get().unwrap(),
@@ -397,8 +397,8 @@ async fn main() -> anyhow::Result<()> {
 
                     let documents = DocumentsBatchReader::from_reader(Cursor::new(documents))?;
 
-                    builder.add_documents(documents)?;
-
+                    let (builder, user_error) = builder.add_documents(documents)?;
+                    let _count = user_error?;
                     let result = builder.execute();
 
                     match result {
diff --git a/milli/src/index.rs b/milli/src/index.rs
index 9637b4103..272877912 100644
--- a/milli/src/index.rs
+++ b/milli/src/index.rs
@@ -1212,10 +1212,11 @@ pub(crate) mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1234,7 +1235,7 @@ pub(crate) mod tests {
         // we add all the documents a second time. we are supposed to get the same
         // field_distribution in the end
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
         let content = documents!([
@@ -1242,7 +1243,8 @@ pub(crate) mod tests {
             { "id": 2, "name": "bob", "age": 20 },
             { "id": 2, "name": "bob", "age": 20 },
         ]);
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1265,10 +1267,11 @@ pub(crate) mod tests {
         ]);
 
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1333,10 +1336,11 @@ pub(crate) mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1390,10 +1394,11 @@ pub(crate) mod tests {
         ]);
 
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
diff --git a/milli/src/search/distinct/mod.rs b/milli/src/search/distinct/mod.rs
index 670fa01ac..1a9c56cf3 100644
--- a/milli/src/search/distinct/mod.rs
+++ b/milli/src/search/distinct/mod.rs
@@ -97,14 +97,15 @@ mod test {
             update_method: IndexDocumentsMethod::ReplaceDocuments,
             ..Default::default()
         };
-        let mut addition =
+        let addition =
             IndexDocuments::new(&mut txn, &index, &config, indexing_config, |_| ()).unwrap();
 
         let reader =
             crate::documents::DocumentsBatchReader::from_reader(Cursor::new(JSON.as_slice()))
                 .unwrap();
 
-        addition.add_documents(reader).unwrap();
+        let (addition, user_error) = addition.add_documents(reader).unwrap();
+        user_error.unwrap();
         addition.execute().unwrap();
 
         let fields_map = index.fields_ids_map(&txn).unwrap();
diff --git a/milli/src/search/facet/filter.rs b/milli/src/search/facet/filter.rs
index d89413f62..41e2f0657 100644
--- a/milli/src/search/facet/filter.rs
+++ b/milli/src/search/facet/filter.rs
@@ -648,10 +648,11 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
diff --git a/milli/src/update/clear_documents.rs b/milli/src/update/clear_documents.rs
index d1939df7b..3fe57eeae 100644
--- a/milli/src/update/clear_documents.rs
+++ b/milli/src/update/clear_documents.rs
@@ -100,9 +100,10 @@ mod tests {
         ]);
         let indexing_config = IndexDocumentsConfig::default();
         let config = IndexerConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // Clear all documents from the database.
diff --git a/milli/src/update/delete_documents.rs b/milli/src/update/delete_documents.rs
index 3b519c101..49e7de8ae 100644
--- a/milli/src/update/delete_documents.rs
+++ b/milli/src/update/delete_documents.rs
@@ -657,13 +657,13 @@ mod tests {
     fn insert_documents<'t, R: std::io::Read + std::io::Seek>(
         wtxn: &mut RwTxn<'t, '_>,
         index: &'t Index,
-        documents: crate::documents::DocumentBatchReader<R>,
+        documents: crate::documents::DocumentsBatchReader<R>,
     ) {
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
-            IndexDocuments::new(wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(documents).unwrap();
+        let builder = IndexDocuments::new(wtxn, &index, &config, indexing_config, |_| ()).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
     }
 
@@ -701,9 +701,10 @@ mod tests {
         ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // delete those documents, ids are synchronous therefore 0, 1, and 2.
@@ -736,9 +737,10 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // Delete not all of the documents but some of them.
diff --git a/milli/src/update/index_documents/mod.rs b/milli/src/update/index_documents/mod.rs
index 2fb7cbcd9..ae42483f0 100644
--- a/milli/src/update/index_documents/mod.rs
+++ b/milli/src/update/index_documents/mod.rs
@@ -141,7 +141,12 @@ where
         // We check for user errors in this validator and if there is one, we can return
         // the `IndexDocument` struct as it is valid to send more documents into it.
         // However, if there is an internal error we throw it away!
-        let reader = match validate_documents_batch(self.wtxn, self.index, reader)? {
+        let reader = match validate_documents_batch(
+            self.wtxn,
+            self.index,
+            self.config.autogenerate_docids,
+            reader,
+        )? {
             Ok(reader) => reader,
             Err(user_error) => return Ok((self, Err(user_error))),
         };
@@ -626,10 +631,11 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -642,10 +648,11 @@ mod tests {
         // Second we send 1 document with id 1, to erase the previous ones.
         let mut wtxn = index.write_txn().unwrap();
         let content = documents!([ { "id": 1, "name": "updated kevin" } ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -662,9 +669,11 @@ mod tests {
             { "id": 2, "name": "updated kevina" },
             { "id": 3, "name": "updated benoit" }
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
+        builder.execute().unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is **always** 3 documents.
@@ -694,10 +703,11 @@ mod tests {
             update_method: IndexDocumentsMethod::UpdateDocuments,
             ..Default::default()
         };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -722,9 +732,10 @@ mod tests {
         // Second we send 1 document with id 1, to force it to be merged with the previous one.
         let mut wtxn = index.write_txn().unwrap();
         let content = documents!([ { "id": 1, "age": 25 } ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -765,7 +776,7 @@ mod tests {
         ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
         assert!(builder.add_documents(content).is_err());
         wtxn.commit().unwrap();
@@ -794,10 +805,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -814,9 +826,10 @@ mod tests {
         // Second we send 1 document with the generated uuid, to erase the previous ones.
         let mut wtxn = index.write_txn().unwrap();
         let content = documents!([ { "name": "updated kevin", "id": kevin_uuid } ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -856,9 +869,10 @@ mod tests {
         ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -873,9 +887,10 @@ mod tests {
         let content = documents!([ { "name": "new kevin" } ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -898,9 +913,10 @@ mod tests {
         let content = documents!([]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -924,7 +940,7 @@ mod tests {
         let content = documents!([ { "id": "brume bleue", "name": "kevin" } ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
         assert!(builder.add_documents(content).is_err());
@@ -934,9 +950,10 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         // There is a space in the document id.
         let content = documents!([ { "id": 32, "name": "kevin" } ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -963,9 +980,10 @@ mod tests {
         ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1009,9 +1027,10 @@ mod tests {
             update_method: IndexDocumentsMethod::ReplaceDocuments,
             ..Default::default()
         };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1020,7 +1039,7 @@ mod tests {
             update_method: IndexDocumentsMethod::UpdateDocuments,
             ..Default::default()
         };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
         let documents = documents!([
           {
@@ -1030,7 +1049,8 @@ mod tests {
           }
         ]);
 
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
     }
@@ -1057,9 +1077,10 @@ mod tests {
             update_method: IndexDocumentsMethod::ReplaceDocuments,
             ..Default::default()
         };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1099,10 +1120,11 @@ mod tests {
           { "id": 2, "_geo": { "lng": "42" }, "_geo.lat": "31" },
           { "id": 3, "_geo.lat": 31, "_geo.lng": "42" },
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1138,10 +1160,11 @@ mod tests {
         let documents = documents!([
           { "id": 0, "_geo": { "lng": 42 } }
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         let error = builder.execute().unwrap_err();
         assert_eq!(
             &error.to_string(),
@@ -1151,10 +1174,11 @@ mod tests {
         let documents = documents!([
           { "id": 0, "_geo": { "lat": 42 } }
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         let error = builder.execute().unwrap_err();
         assert_eq!(
             &error.to_string(),
@@ -1164,10 +1188,11 @@ mod tests {
         let documents = documents!([
           { "id": 0, "_geo": { "lat": "lol", "lng": 42 } }
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         let error = builder.execute().unwrap_err();
         assert_eq!(
             &error.to_string(),
@@ -1177,10 +1202,11 @@ mod tests {
         let documents = documents!([
           { "id": 0, "_geo": { "lat": [12, 13], "lng": 42 } }
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         let error = builder.execute().unwrap_err();
         assert_eq!(
             &error.to_string(),
@@ -1190,10 +1216,11 @@ mod tests {
         let documents = documents!([
           { "id": 0, "_geo": { "lat": 12, "lng": "hello" } }
         ]);
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(documents).unwrap();
+        let (builder, user_error) = builder.add_documents(documents).unwrap();
+        user_error.unwrap();
         let error = builder.execute().unwrap_err();
         assert_eq!(
             &error.to_string(),
@@ -1217,10 +1244,11 @@ mod tests {
         ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         assert_eq!(index.primary_key(&wtxn).unwrap(), Some("objectId"));
@@ -1237,10 +1265,11 @@ mod tests {
             { "objectId": 30,  "title": "Hamlet", "_geo": { "lat": 12, "lng": 89 } }
         ]);
 
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         let external_documents_ids = index.external_documents_ids(&wtxn).unwrap();
         assert!(external_documents_ids.get("30").is_some());
@@ -1249,10 +1278,11 @@ mod tests {
             { "objectId": 30,  "title": "Hamlet", "_geo": { "lat": 12, "lng": 89 } }
         ]);
 
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1281,10 +1311,11 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1315,10 +1346,11 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1373,10 +1405,11 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1426,10 +1459,11 @@ mod tests {
 
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1558,10 +1592,11 @@ mod tests {
         ]);
 
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1628,10 +1663,11 @@ mod tests {
         // index the documents
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1720,10 +1756,11 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1737,10 +1774,11 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1759,10 +1797,11 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1787,10 +1826,11 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1832,10 +1872,11 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
     }
@@ -1870,10 +1911,11 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // Create one long document
@@ -1884,10 +1926,11 @@ mod tests {
         // Index this one long document
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         wtxn.commit().unwrap();
@@ -1901,7 +1944,7 @@ mod tests {
         let index = Index::new(options, tmp).unwrap();
         let mut wtxn = index.write_txn().unwrap();
         let indexer_config = IndexerConfig::default();
-        let mut builder = IndexDocuments::new(
+        let builder = IndexDocuments::new(
             &mut wtxn,
             &index,
             &indexer_config,
@@ -1930,8 +1973,10 @@ mod tests {
             "branch_id_number": 0
         }]};
 
-        builder.add_documents(doc1).unwrap();
-        builder.add_documents(doc2).unwrap();
+        let (builder, user_error) = builder.add_documents(doc1).unwrap();
+        user_error.unwrap();
+        let (builder, user_error) = builder.add_documents(doc2).unwrap();
+        user_error.unwrap();
 
         builder.execute().unwrap();
 
diff --git a/milli/src/update/index_documents/validate.rs b/milli/src/update/index_documents/validate.rs
index b4c0cb68f..0ed1f1cc0 100644
--- a/milli/src/update/index_documents/validate.rs
+++ b/milli/src/update/index_documents/validate.rs
@@ -15,6 +15,7 @@ use crate::{Index, Result};
 pub fn validate_documents_batch<R: Read + Seek>(
     rtxn: &heed::RoTxn,
     index: &Index,
+    autogenerate_docids: bool,
     reader: DocumentsBatchReader<R>,
 ) -> Result<StdResult<DocumentsBatchReader<R>, UserError>> {
     let mut cursor = reader.into_cursor();
diff --git a/milli/src/update/settings.rs b/milli/src/update/settings.rs
index ccf29eb49..5f39579b7 100644
--- a/milli/src/update/settings.rs
+++ b/milli/src/update/settings.rs
@@ -735,10 +735,11 @@ mod tests {
         ]);
         let config = IndexerConfig::default();
         let indexing_config = IndexDocumentsConfig::default();
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -798,10 +799,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -850,10 +852,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -880,10 +883,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // In the same transaction we change the displayed fields to be only the age.
@@ -934,10 +938,11 @@ mod tests {
         ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -974,10 +979,11 @@ mod tests {
 
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1016,10 +1022,11 @@ mod tests {
         ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1067,10 +1074,11 @@ mod tests {
         ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1110,10 +1118,11 @@ mod tests {
         ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1142,10 +1151,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1172,10 +1182,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // In the same transaction we provide some stop_words
@@ -1251,10 +1262,11 @@ mod tests {
         let config = IndexerConfig::default();
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
 
         // In the same transaction provide some synonyms
@@ -1389,10 +1401,11 @@ mod tests {
         ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
@@ -1452,10 +1465,11 @@ mod tests {
         ]);
         let indexing_config =
             IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-        let mut builder =
+        let builder =
             IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
                 .unwrap();
-        builder.add_documents(content).unwrap();
+        let (builder, user_error) = builder.add_documents(content).unwrap();
+        user_error.unwrap();
         builder.execute().unwrap();
         wtxn.commit().unwrap();
 
diff --git a/milli/tests/search/facet_distribution.rs b/milli/tests/search/facet_distribution.rs
index 8890285e7..83d692d7f 100644
--- a/milli/tests/search/facet_distribution.rs
+++ b/milli/tests/search/facet_distribution.rs
@@ -29,8 +29,7 @@ fn test_facet_distribution_with_no_facet_values() {
     let config = IndexerConfig { max_memory: Some(10 * 1024 * 1024), ..Default::default() };
     let indexing_config = IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
 
-    let mut builder =
-        IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
+    let builder = IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
     let mut documents_builder = DocumentsBatchBuilder::new(Vec::new());
     let reader = Cursor::new(
         r#"{
@@ -55,7 +54,8 @@ fn test_facet_distribution_with_no_facet_values() {
 
     // index documents
     let content = DocumentsBatchReader::from_reader(Cursor::new(vector)).unwrap();
-    builder.add_documents(content).unwrap();
+    let (builder, user_error) = builder.add_documents(content).unwrap();
+    user_error.unwrap();
     builder.execute().unwrap();
 
     wtxn.commit().unwrap();
diff --git a/milli/tests/search/mod.rs b/milli/tests/search/mod.rs
index 0b6ce80cc..3b8960fcc 100644
--- a/milli/tests/search/mod.rs
+++ b/milli/tests/search/mod.rs
@@ -61,8 +61,7 @@ pub fn setup_search_index_with_criteria(criteria: &[Criterion]) -> Index {
     let config = IndexerConfig { max_memory: Some(10 * 1024 * 1024), ..Default::default() };
     let indexing_config = IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
 
-    let mut builder =
-        IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
+    let builder = IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
     let mut documents_builder = DocumentsBatchBuilder::new(Vec::new());
     let reader = Cursor::new(CONTENT.as_bytes());
 
@@ -75,7 +74,8 @@ pub fn setup_search_index_with_criteria(criteria: &[Criterion]) -> Index {
 
     // index documents
     let content = DocumentsBatchReader::from_reader(Cursor::new(vector)).unwrap();
-    builder.add_documents(content).unwrap();
+    let (builder, user_error) = builder.add_documents(content).unwrap();
+    user_error.unwrap();
     builder.execute().unwrap();
 
     wtxn.commit().unwrap();
diff --git a/milli/tests/search/query_criteria.rs b/milli/tests/search/query_criteria.rs
index 89a6a6eec..a96366f5e 100644
--- a/milli/tests/search/query_criteria.rs
+++ b/milli/tests/search/query_criteria.rs
@@ -390,8 +390,7 @@ fn criteria_ascdesc() {
     // index documents
     let config = IndexerConfig { max_memory: Some(10 * 1024 * 1024), ..Default::default() };
     let indexing_config = IndexDocumentsConfig { autogenerate_docids: true, ..Default::default() };
-    let mut builder =
-        IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
+    let builder = IndexDocuments::new(&mut wtxn, &index, &config, indexing_config, |_| ()).unwrap();
 
     let mut batch_builder = DocumentsBatchBuilder::new(Vec::new());
 
@@ -422,7 +421,8 @@ fn criteria_ascdesc() {
     let vector = batch_builder.into_inner().unwrap();
 
     let reader = DocumentsBatchReader::from_reader(Cursor::new(vector)).unwrap();
-    builder.add_documents(reader).unwrap();
+    let (builder, user_error) = builder.add_documents(reader).unwrap();
+    user_error.unwrap();
     builder.execute().unwrap();
 
     wtxn.commit().unwrap();
diff --git a/milli/tests/search/typo_tolerance.rs b/milli/tests/search/typo_tolerance.rs
index 63bf22579..7c4cf8971 100644
--- a/milli/tests/search/typo_tolerance.rs
+++ b/milli/tests/search/typo_tolerance.rs
@@ -127,11 +127,10 @@ fn test_typo_disabled_on_word() {
     let mut txn = index.write_txn().unwrap();
     let config = IndexerConfig::default();
     let indexing_config = IndexDocumentsConfig::default();
-    let mut builder =
-        IndexDocuments::new(&mut txn, &index, &config, indexing_config, |_| ()).unwrap();
-
-    builder.add_documents(documents).unwrap();
+    let builder = IndexDocuments::new(&mut txn, &index, &config, indexing_config, |_| ()).unwrap();
 
+    let (builder, user_error) = builder.add_documents(documents).unwrap();
+    user_error.unwrap();
     builder.execute().unwrap();
     txn.commit().unwrap();