Expand and test Inserter trait (#525)

Based on #507 by @yutannihilation

Author: mlafeldt

crates/duckdb/src/core/vector.rs

@@ -144,6 +144,12 @@ impl Inserter<&str> for FlatVector {
     }
 }
 
+impl Inserter<&String> for FlatVector {
+    fn insert(&self, index: usize, value: &String) {
+        self.insert(index, value.as_str());
+    }
+}
+
 impl Inserter<&[u8]> for FlatVector {
     fn insert(&self, index: usize, value: &[u8]) {
         let value_size = value.len();
@@ -159,6 +165,12 @@ impl Inserter<&[u8]> for FlatVector {
     }
 }
 
+impl Inserter<&Vec<u8>> for FlatVector {
+    fn insert(&self, index: usize, value: &Vec<u8>) {
+        self.insert(index, value.as_slice());
+    }
+}
+
 /// A list vector.
 pub struct ListVector {
     /// ListVector does not own the vector pointer.
@@ -352,3 +364,35 @@ impl StructVector {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::core::{DataChunkHandle, LogicalTypeId};
+    use std::ffi::CString;
+
+    #[test]
+    fn test_insert_string_values() {
+        let chunk = DataChunkHandle::new(&[LogicalTypeId::Varchar.into()]);
+        let vector = chunk.flat_vector(0);
+        chunk.set_len(3);
+
+        vector.insert(0, "first");
+        vector.insert(1, &String::from("second"));
+        let cstring = CString::new("third").unwrap();
+        vector.insert(2, cstring);
+    }
+
+    #[test]
+    fn test_insert_byte_values() {
+        let chunk = DataChunkHandle::new(&[LogicalTypeId::Blob.into()]);
+        let vector = chunk.flat_vector(0);
+        chunk.set_len(2);
+
+        vector.insert(0, b"hello world".as_slice());
+        vector.insert(
+            1,
+            &vec![0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64],
+        );
+    }
+}