Use String instead of bytes, change error handling

src/hyperfine/export/csv.rs

@@ -6,16 +6,17 @@ use std::io::{Error, ErrorKind, Result};
 pub struct CsvExporter {}
 
 impl Exporter for CsvExporter {
-    fn serialize(&self, results: &Vec<ExportEntry>) -> Result<Vec<u8>> {
+    fn serialize(&self, results: &Vec<ExportEntry>) -> Result<String> {
         let mut writer = WriterBuilder::new().from_writer(vec![]);
         for res in results {
             writer.serialize(res)?;
         }
 
-        if let Ok(inner) = writer.into_inner() {
-            return Ok(inner);
-        }
-        Err(Error::new(ErrorKind::Other, "Error serializing to CSV"))
+        writer
+            .into_inner()
+            .ok()
+            .and_then(|bytes| String::from_utf8(bytes).ok())
+            .ok_or(Error::new(ErrorKind::Other, "Error serializing to CSV"))
     }
 }
 

src/hyperfine/export/json.rs

@@ -2,7 +2,7 @@ use super::{ExportEntry, Exporter};
 
 use std::io::{Error, ErrorKind, Result};
 
-use serde_json::to_vec_pretty;
+use serde_json::to_string_pretty;
 
 #[derive(Serialize, Debug)]
 struct HyperfineSummary<'a> {
@@ -12,13 +12,15 @@ struct HyperfineSummary<'a> {
 pub struct JsonExporter {}
 
 impl Exporter for JsonExporter {
-    fn serialize(&self, results: &Vec<ExportEntry>) -> Result<Vec<u8>> {
-        let serialized = to_vec_pretty(&HyperfineSummary { results });
+    fn serialize(&self, results: &Vec<ExportEntry>) -> Result<String> {
+        let serialized = to_string_pretty(&HyperfineSummary { results });
 
-        match serialized {
-            Ok(file_content) => Ok(file_content),
-            Err(e) => Err(Error::new(ErrorKind::Other, format!("{:?}", e))),
-        }
+        serialized.map_err(|e| {
+            Error::new(
+                ErrorKind::Other,
+                format!("Error while serializing to JSON: {:}", e),
+            )
+        })
     }
 }
 

src/hyperfine/export/mod.rs

@@ -70,7 +70,7 @@ pub enum ExportType {
 /// Interface for different exporters.
 trait Exporter {
     /// Export the given entries in the serialized form.
-    fn serialize(&self, values: &Vec<ExportEntry>) -> Result<Vec<u8>>;
+    fn serialize(&self, results: &Vec<ExportEntry>) -> Result<String>;
 }
 
 /// Handles the management of multiple file exporters.
@@ -107,8 +107,8 @@ impl ExportManager {
 }
 
 /// Write the given content to a file with the specified name
-fn write_to_file(filename: &str, content: Vec<u8>) -> Result<()> {
+fn write_to_file(filename: &str, content: String) -> Result<()> {
     let mut file = File::create(filename)?;
-    file.write_all(&content)?;
+    file.write_all(content.as_bytes())?;
     Ok(())
 }