Fix clippy warnings

Author: michaelmior

src/db.rs

@@ -1,7 +1,7 @@
 use crate::jstable;
 use crate::log::{LogEntry, Logger, Operation};
 use crate::storage::MemTable;
-use serde_json::{json, Value};
+use serde_json::Value;
 use std::fs;
 use uuid::Uuid;
 

src/log.rs

@@ -37,7 +37,6 @@ impl Logger {
         let path = path.as_ref().to_path_buf();
         let file = OpenOptions::new()
             .create(true)
-            .write(true)
             .append(true)
             .open(&path)?;
         Ok(Logger {
@@ -64,7 +63,6 @@ impl Logger {
         fs::rename(&self.path, new_path)?;
         self.file = OpenOptions::new()
             .create(true)
-            .write(true)
             .append(true)
             .open(&self.path)?;
         Ok(())

src/schema.rs

@@ -74,7 +74,7 @@ pub fn infer_schema(doc: &Value) -> Schema {
         }
         Value::String(_) => Schema::new(SchemaType::String),
         Value::Array(arr) => {
-            let mut items_schema = if let Some(first) = arr.get(0) {
+            let mut items_schema = if let Some(first) = arr.first() {
                 infer_schema(first)
             } else {
                 // Empty array, we can't infer the type.

src/storage.rs

@@ -8,6 +8,12 @@ pub struct MemTable {
     schema: Schema,
 }
 
+impl Default for MemTable {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl MemTable {
     pub fn new() -> Self {
         MemTable {
@@ -24,6 +30,10 @@ impl MemTable {
         self.documents.len()
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.documents.is_empty()
+    }
+
     pub fn flush(&self, path: &str) -> std::io::Result<()> {
         let timestamp = std::time::SystemTime::now()
             .duration_since(std::time::UNIX_EPOCH)