Address clippy warnings (#1553)

* Fix 'new_without_default' clippy warnings

* Fix 'from_over_into' clippy warnings

* Push 'allow(module_inception)' down from lib.rs

* Fix 'complex_type' clippy warning with type alias

* Remove unused yet allowed clippy warnings

* Fix 'new_without_default' clippy warnings for tests

Author: sergey-melnychuk

datafusion/src/catalog/catalog.rs

@@ -59,6 +59,12 @@ impl MemoryCatalogList {
     }
 }
 
+impl Default for MemoryCatalogList {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl CatalogList for MemoryCatalogList {
     fn as_any(&self) -> &dyn Any {
         self
@@ -84,6 +90,12 @@ impl CatalogList for MemoryCatalogList {
     }
 }
 
+impl Default for MemoryCatalogProvider {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// Represents a catalog, comprising a number of named schemas.
 pub trait CatalogProvider: Sync + Send {
     /// Returns the catalog provider as [`Any`](std::any::Any)

datafusion/src/catalog/mod.rs

@@ -18,6 +18,7 @@
 //! This module contains interfaces and default implementations
 //! of table namespacing concepts, including catalogs and schemas.
 
+#![allow(clippy::module_inception)]
 pub mod catalog;
 pub mod information_schema;
 pub mod schema;

datafusion/src/catalog/schema.rs

@@ -79,6 +79,12 @@ impl MemorySchemaProvider {
     }
 }
 
+impl Default for MemorySchemaProvider {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl SchemaProvider for MemorySchemaProvider {
     fn as_any(&self) -> &dyn Any {
         self

datafusion/src/datasource/mod.rs

@@ -17,6 +17,7 @@
 
 //! DataFusion data sources
 
+#![allow(clippy::module_inception)]
 pub mod datasource;
 pub mod empty;
 pub mod file_format;

datafusion/src/datasource/object_store/mod.rs

@@ -186,6 +186,12 @@ impl fmt::Debug for ObjectStoreRegistry {
     }
 }
 
+impl Default for ObjectStoreRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl ObjectStoreRegistry {
     /// Create the registry that object stores can registered into.
     /// ['LocalFileSystem'] store is registered in by default to support read local files natively.

datafusion/src/execution/context.rs

@@ -141,6 +141,12 @@ pub struct ExecutionContext {
     pub state: Arc<Mutex<ExecutionContextState>>,
 }
 
+impl Default for ExecutionContext {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl ExecutionContext {
     /// Creates a new execution context using a default configuration.
     pub fn new() -> Self {
@@ -1049,6 +1055,27 @@ pub struct ExecutionProps {
     pub(crate) query_execution_start_time: DateTime<Utc>,
 }
 
+impl Default for ExecutionProps {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl ExecutionProps {
+    /// Creates a new execution props
+    pub fn new() -> Self {
+        ExecutionProps {
+            query_execution_start_time: chrono::Utc::now(),
+        }
+    }
+
+    /// Marks the execution of query started timestamp
+    pub fn start_execution(&mut self) -> &Self {
+        self.query_execution_start_time = chrono::Utc::now();
+        &*self
+    }
+}
+
 /// Execution context for registering data sources and executing queries
 #[derive(Clone)]
 pub struct ExecutionContextState {
@@ -1068,18 +1095,9 @@ pub struct ExecutionContextState {
     pub object_store_registry: Arc<ObjectStoreRegistry>,
 }
 
-impl ExecutionProps {
-    /// Creates a new execution props
-    pub fn new() -> Self {
-        ExecutionProps {
-            query_execution_start_time: chrono::Utc::now(),
-        }
-    }
-
-    /// Marks the execution of query started timestamp
-    pub fn start_execution(&mut self) -> &Self {
-        self.query_execution_start_time = chrono::Utc::now();
-        &*self
+impl Default for ExecutionContextState {
+    fn default() -> Self {
+        Self::new()
     }
 }
 

datafusion/src/execution/options.rs

@@ -46,6 +46,12 @@ pub struct CsvReadOptions<'a> {
     pub file_extension: &'a str,
 }
 
+impl<'a> Default for CsvReadOptions<'a> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<'a> CsvReadOptions<'a> {
     /// Create a CSV read option with default presets
     pub fn new() -> Self {

datafusion/src/lib.rs

@@ -15,15 +15,6 @@
 // specific language governing permissions and limitations
 // under the License.
 #![warn(missing_docs, clippy::needless_borrow)]
-// Clippy lints, some should be disabled incrementally
-#![allow(
-    clippy::float_cmp,
-    clippy::from_over_into,
-    clippy::module_inception,
-    clippy::new_without_default,
-    clippy::type_complexity,
-    clippy::upper_case_acronyms
-)]
 
 //! [DataFusion](https://github.com/apache/arrow-datafusion)
 //! is an extensible query execution framework that uses

datafusion/src/logical_plan/dfschema.rs

@@ -297,11 +297,12 @@ impl DFSchema {
     }
 }
 
-impl Into<Schema> for DFSchema {
-    /// Convert a schema into a DFSchema
-    fn into(self) -> Schema {
+impl From<DFSchema> for Schema {
+    /// Convert DFSchema into a Schema
+    fn from(df_schema: DFSchema) -> Self {
         Schema::new(
-            self.fields
+            df_schema
+                .fields
                 .into_iter()
                 .map(|f| {
                     if f.qualifier().is_some() {
@@ -319,10 +320,10 @@ impl Into<Schema> for DFSchema {
     }
 }
 
-impl Into<Schema> for &DFSchema {
-    /// Convert a schema into a DFSchema
-    fn into(self) -> Schema {
-        Schema::new(self.fields.iter().map(|f| f.field.clone()).collect())
+impl From<&DFSchema> for Schema {
+    /// Convert DFSchema reference into a Schema
+    fn from(df_schema: &DFSchema) -> Self {
+        Schema::new(df_schema.fields.iter().map(|f| f.field.clone()).collect())
     }
 }
 
@@ -340,9 +341,9 @@ impl TryFrom<Schema> for DFSchema {
     }
 }
 
-impl Into<SchemaRef> for DFSchema {
-    fn into(self) -> SchemaRef {
-        SchemaRef::new(self.into())
+impl From<DFSchema> for SchemaRef {
+    fn from(df_schema: DFSchema) -> Self {
+        SchemaRef::new(df_schema.into())
     }
 }
 

datafusion/src/optimizer/common_subexpr_eliminate.rs

@@ -69,6 +69,12 @@ impl OptimizerRule for CommonSubexprEliminate {
     }
 }
 
+impl Default for CommonSubexprEliminate {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl CommonSubexprEliminate {
     #[allow(missing_docs)]
     pub fn new() -> Self {