diff --git a/dozer-cli/Cargo.toml b/dozer-cli/Cargo.toml
index ead43df48e..4f35b24589 100644
--- a/dozer-cli/Cargo.toml
+++ b/dozer-cli/Cargo.toml
@@ -68,3 +68,5 @@ snowflake = ["dozer-ingestion/snowflake"]
 mongodb = ["dozer-ingestion/mongodb"]
 onnx = ["dozer-sql/onnx"]
 tokio-console = ["dozer-tracing/tokio-console"]
+javascript = ["dozer-ingestion/javascript", "dozer-sql/javascript"]
+datafusion = ["dozer-ingestion/datafusion"]
diff --git a/dozer-ingestion/tests/test_suite/mod.rs b/dozer-ingestion/tests/test_suite/mod.rs
index 309fe6642a..58ee1af7e5 100644
--- a/dozer-ingestion/tests/test_suite/mod.rs
+++ b/dozer-ingestion/tests/test_suite/mod.rs
@@ -51,6 +51,6 @@ pub use basic::{
 #[cfg(feature = "mongodb")]
 pub use connectors::MongodbConnectorTest;
 
-pub use connectors::PostgresConnectorTest;
 #[cfg(feature = "datafusion")]
-pub use LocalStorageObjectStoreConnectorTest;
+pub use connectors::LocalStorageObjectStoreConnectorTest;
+pub use connectors::PostgresConnectorTest;
diff --git a/dozer-sql/Cargo.toml b/dozer-sql/Cargo.toml
index 6a86af5523..00d9aa1183 100644
--- a/dozer-sql/Cargo.toml
+++ b/dozer-sql/Cargo.toml
@@ -27,3 +27,4 @@ proptest = "1.3.1"
 [features]
 python = ["dozer-sql-expression/python"]
 onnx = ["dozer-sql-expression/onnx"]
+javascript = ["dozer-sql-expression/javascript"]
diff --git a/dozer-sql/expression/src/builder.rs b/dozer-sql/expression/src/builder.rs
index 1d78330931..19a6d25028 100644
--- a/dozer-sql/expression/src/builder.rs
+++ b/dozer-sql/expression/src/builder.rs
@@ -547,7 +547,7 @@ impl ExpressionBuilder {
                 }
 
                 UdfType::JavaScript(config) => {
-                    #[cfg(feature = "javasscript")]
+                    #[cfg(feature = "javascript")]
                     {
                         self.parse_javascript_udf(
                             function_name.clone(),
@@ -562,7 +562,7 @@ impl ExpressionBuilder {
                     #[cfg(not(feature = "javascript"))]
                     {
                         let _ = config;
-                        Err(Error::OnnxNotEnabled)
+                        Err(Error::JavaScriptNotEnabled)
                     }
                 }
             };
diff --git a/dozer-sql/expression/src/error.rs b/dozer-sql/expression/src/error.rs
index 1fd7a9bef1..2b923ff8bf 100644
--- a/dozer-sql/expression/src/error.rs
+++ b/dozer-sql/expression/src/error.rs
@@ -103,7 +103,7 @@ pub enum Error {
     #[error("Javascript is not enabled")]
     JavaScriptNotEnabled,
 
-    #[cfg(feature = "javasscript")]
+    #[cfg(feature = "javascript")]
     #[error("JavaScript UDF error: {0}")]
     JavaScript(#[from] crate::javascript::Error),
 
diff --git a/dozer-sql/expression/src/scalar/string.rs b/dozer-sql/expression/src/scalar/string.rs
index b8680105f6..28589eabca 100644
--- a/dozer-sql/expression/src/scalar/string.rs
+++ b/dozer-sql/expression/src/scalar/string.rs
@@ -407,42 +407,54 @@ pub(crate) fn evaluate_substr(
     let arg_value = arg_field.to_string();
 
     let position_field = position.evaluate(record, schema)?;
-    let position_result = position_field.to_uint();
-    if position_result.is_none() {
-        return Err(Error::InvalidFunctionArgument {
+    let position_value = position_field
+        .to_int()
+        .ok_or_else(|| Error::InvalidFunctionArgument {
             function_name: "SUBSTR".to_string(),
             argument_index: 1,
             argument: position_field,
-        });
-    }
-    let position_value = position_result.unwrap();
+        })?;
+    // 0 is treated as 1
+    let position_value_normalized = if position_value == 0 {
+        1
+    } else {
+        position_value
+    };
 
     let length_value = match length {
         Some(length_expr) => {
             let length_field = length_expr.evaluate(record, schema)?;
-            let length_result = length_field.to_i128();
-            if length_result.is_none() {
-                return Err(Error::InvalidFunctionArgument {
+            let length = length_field
+                .to_int()
+                .ok_or_else(|| Error::InvalidFunctionArgument {
                     function_name: "SUBSTR".to_string(),
                     argument_index: 2,
                     argument: length_field,
-                });
+                })?;
+            if length < 1 {
+                return Ok(Field::Null);
             }
-            length_result.unwrap()
+            length as usize
         }
-        None => arg_value.len() as i128,
+        None => arg_value.len(),
     };
 
-    let mut iter = arg_value.char_indices();
-    let (start, _) = iter
-        .nth(position_value as usize)
-        .unwrap_or((arg_value.len(), ' '));
-    let (end, _) = iter
-        .nth(length_value as usize)
-        .unwrap_or((arg_value.len(), ' '));
-    let result = &arg_value[start..end];
+    let start = if position_value_normalized >= 1 {
+        arg_value
+            .char_indices()
+            .nth(position_value_normalized as usize - 1)
+            .map_or(arg_value.len(), |(i, _)| i)
+    } else {
+        arg_value
+            .char_indices()
+            .nth_back((-position_value_normalized) as usize - 1)
+            .map_or(0, |(i, _)| i)
+    };
 
-    Ok(Field::String(result.to_owned()))
+    let remainder = &arg_value[start..];
+    Ok(Field::String(
+        remainder.chars().take(length_value).collect(),
+    ))
 }
 
 pub fn validate_replace(args: &[Expression], schema: &Schema) -> Result<ExpressionType, Error> {
diff --git a/json_schemas/connections.json b/json_schemas/connections.json
index c929085d1a..c860d813bd 100644
--- a/json_schemas/connections.json
+++ b/json_schemas/connections.json
@@ -7,12 +7,12 @@
       "description": "Configuration for a Postgres connection",
       "examples": [
         {
-          "database": "postgres",
-          "host": "localhost",
+          "user": "postgres",
           "password": "postgres",
+          "host": "localhost",
           "port": 5432,
-          "schema": "public",
-          "user": "postgres"
+          "database": "postgres",
+          "schema": "public"
         }
       ],
       "type": "object",
@@ -97,11 +97,11 @@
         {
           "provider": {
             "Log": {
+              "wss_url": "",
               "filter": {
                 "from_block": 0,
                 "to_block": null
-              },
-              "wss_url": ""
+              }
             }
           }
         }
@@ -266,12 +266,12 @@
       "title": "GrpcConfig",
       "examples": [
         {
-          "adapter": "arrow",
           "host": "localhost",
           "port": 50051,
           "schemas": {
             "Path": "schema.json"
-          }
+          },
+          "adapter": "arrow"
         }
       ],
       "type": "object",
@@ -342,15 +342,15 @@
       "title": "SnowflakeConfig",
       "examples": [
         {
-          "database": "database",
-          "driver": "SnowflakeDSIIDriver",
-          "password": "password",
-          "port": "443",
-          "role": "role",
-          "schema": "schema",
           "server": "<account_name>.<region_id>.snowflakecomputing.com",
+          "port": "443",
           "user": "bob",
-          "warehouse": "warehouse"
+          "password": "password",
+          "database": "database",
+          "schema": "schema",
+          "warehouse": "warehouse",
+          "driver": "SnowflakeDSIIDriver",
+          "role": "role"
         }
       ],
       "type": "object",
@@ -439,16 +439,16 @@
         {
           "details": {
             "access_key_id": "",
-            "bucket_name": "",
+            "secret_access_key": "",
             "region": "",
-            "secret_access_key": ""
+            "bucket_name": ""
           },
           "tables": [
             {
               "config": {
                 "CSV": {
-                  "extension": ".csv",
-                  "path": "path/to/file"
+                  "path": "path/to/file",
+                  "extension": ".csv"
                 }
               },
               "name": "table_name"
@@ -598,8 +598,8 @@
             {
               "config": {
                 "CSV": {
-                  "extension": ".csv",
-                  "path": "path/to/table"
+                  "path": "path/to/table",
+                  "extension": ".csv"
                 }
               },
               "name": "table_name"
@@ -732,8 +732,8 @@
         {
           "tables": [
             {
-              "name": "",
-              "path": ""
+              "path": "",
+              "name": ""
             }
           ]
         }
@@ -797,8 +797,8 @@
       "title": "MySQLConfig",
       "examples": [
         {
-          "server_id": 1,
-          "url": "mysql://root:1234@localhost:3306/db_name"
+          "url": "mysql://root:1234@localhost:3306/db_name",
+          "server_id": 1
         }
       ],
       "type": "object",
diff --git a/json_schemas/dozer.json b/json_schemas/dozer.json
index 884daad8ac..82c69b1431 100644
--- a/json_schemas/dozer.json
+++ b/json_schemas/dozer.json
@@ -129,9 +129,9 @@
         },
         "replication": {
           "default": {
-            "datacenter": "esp",
             "server_address": "0.0.0.0",
-            "server_port": 5929
+            "server_port": 5929,
+            "datacenter": "esp"
           },
           "allOf": [
             {
@@ -829,8 +829,8 @@
         {
           "tables": [
             {
-              "name": "",
-              "path": ""
+              "path": "",
+              "name": ""
             }
           ]
         }
@@ -968,11 +968,11 @@
         {
           "provider": {
             "Log": {
+              "wss_url": "",
               "filter": {
                 "from_block": 0,
                 "to_block": null
-              },
-              "wss_url": ""
+              }
             }
           }
         }
@@ -1217,12 +1217,12 @@
     "GrpcConfig": {
       "examples": [
         {
-          "adapter": "arrow",
           "host": "localhost",
           "port": 50051,
           "schemas": {
             "Path": "schema.json"
-          }
+          },
+          "adapter": "arrow"
         }
       ],
       "type": "object",
@@ -1355,8 +1355,8 @@
             {
               "config": {
                 "CSV": {
-                  "extension": ".csv",
-                  "path": "path/to/table"
+                  "path": "path/to/table",
+                  "extension": ".csv"
                 }
               },
               "name": "table_name"
@@ -1400,8 +1400,8 @@
     "MySQLConfig": {
       "examples": [
         {
-          "server_id": 1,
-          "url": "mysql://root:1234@localhost:3306/db_name"
+          "url": "mysql://root:1234@localhost:3306/db_name",
+          "server_id": 1
         }
       ],
       "type": "object",
@@ -1597,12 +1597,12 @@
       "description": "Configuration for a Postgres connection",
       "examples": [
         {
-          "database": "postgres",
-          "host": "localhost",
+          "user": "postgres",
           "password": "postgres",
+          "host": "localhost",
           "port": 5432,
-          "schema": "public",
-          "user": "postgres"
+          "database": "postgres",
+          "schema": "public"
         }
       ],
       "type": "object",
@@ -1768,16 +1768,16 @@
         {
           "details": {
             "access_key_id": "",
-            "bucket_name": "",
+            "secret_access_key": "",
             "region": "",
-            "secret_access_key": ""
+            "bucket_name": ""
           },
           "tables": [
             {
               "config": {
                 "CSV": {
-                  "extension": ".csv",
-                  "path": "path/to/file"
+                  "path": "path/to/file",
+                  "extension": ".csv"
                 }
               },
               "name": "table_name"
@@ -1873,15 +1873,15 @@
     "SnowflakeConfig": {
       "examples": [
         {
-          "database": "database",
-          "driver": "SnowflakeDSIIDriver",
-          "password": "password",
-          "port": "443",
-          "role": "role",
-          "schema": "schema",
           "server": "<account_name>.<region_id>.snowflakecomputing.com",
+          "port": "443",
           "user": "bob",
-          "warehouse": "warehouse"
+          "password": "password",
+          "database": "database",
+          "schema": "schema",
+          "warehouse": "warehouse",
+          "driver": "SnowflakeDSIIDriver",
+          "role": "role"
         }
       ],
       "type": "object",
@@ -2140,20 +2140,20 @@
     "WebhookConfig": {
       "examples": [
         {
+          "host": "localhost",
+          "port": 50059,
           "endpoints": [
             {
               "path": "/ingest",
-              "schema": {
-                "Inline": "\n        {\n            \"users\": {\n              \"schema\": {\n                \"fields\": [\n                  {\n                    \"name\": \"id\",\n                    \"typ\": \"Int\",\n                    \"nullable\": false\n                  },\n                  {\n                    \"name\": \"name\",\n                    \"typ\": \"String\",\n                    \"nullable\": true\n                  },\n                  {\n                    \"name\": \"json\",\n                    \"typ\": \"Json\",\n                    \"nullable\": true\n                  }\n                ]\n              }\n            }\n          }\n        "
-              },
               "verbs": [
                 "POST",
                 "DELETE"
-              ]
+              ],
+              "schema": {
+                "Inline": "\n        {\n            \"users\": {\n              \"schema\": {\n                \"fields\": [\n                  {\n                    \"name\": \"id\",\n                    \"typ\": \"Int\",\n                    \"nullable\": false\n                  },\n                  {\n                    \"name\": \"name\",\n                    \"typ\": \"String\",\n                    \"nullable\": true\n                  },\n                  {\n                    \"name\": \"json\",\n                    \"typ\": \"Json\",\n                    \"nullable\": true\n                  }\n                ]\n              }\n            }\n          }\n        "
+              }
             }
-          ],
-          "host": "localhost",
-          "port": 50059
+          ]
         }
       ],
       "type": "object",
@@ -2215,13 +2215,13 @@
       "examples": [
         {
           "path": "/ingest",
-          "schema": {
-            "Inline": "\n        {\n            \"users\": {\n              \"schema\": {\n                \"fields\": [\n                  {\n                    \"name\": \"id\",\n                    \"typ\": \"Int\",\n                    \"nullable\": false\n                  },\n                  {\n                    \"name\": \"name\",\n                    \"typ\": \"String\",\n                    \"nullable\": true\n                  },\n                  {\n                    \"name\": \"json\",\n                    \"typ\": \"Json\",\n                    \"nullable\": true\n                  }\n                ]\n              }\n            }\n          }\n        "
-          },
           "verbs": [
             "POST",
             "DELETE"
-          ]
+          ],
+          "schema": {
+            "Inline": "\n        {\n            \"users\": {\n              \"schema\": {\n                \"fields\": [\n                  {\n                    \"name\": \"id\",\n                    \"typ\": \"Int\",\n                    \"nullable\": false\n                  },\n                  {\n                    \"name\": \"name\",\n                    \"typ\": \"String\",\n                    \"nullable\": true\n                  },\n                  {\n                    \"name\": \"json\",\n                    \"typ\": \"Json\",\n                    \"nullable\": true\n                  }\n                ]\n              }\n            }\n          }\n        "
+          }
         }
       ],
       "type": "object",