Issue #44: Implement exporting table in csv format

crates/gitql-ast/Cargo.toml

@@ -10,3 +10,4 @@ license = "MIT"
 [dependencies]
 lazy_static = "1.4.0"
 chrono = "0.4.31"
+csv = "1.3.0"

crates/gitql-ast/src/object.rs

@@ -1,3 +1,7 @@
+use std::error::Error;
+
+use csv::Writer;
+
 use crate::value::Value;
 
 /// In memory representation of the list of [`Value`] in one Row
@@ -52,4 +56,21 @@ impl GitQLObject {
     pub fn len(&self) -> usize {
         self.groups.len()
     }
+
+    /// Export the GitQLObject as CSV String
+    pub fn as_csv(&self) -> Result<String, Box<dyn Error>> {
+        let mut writer = Writer::from_writer(vec![]);
+        writer.write_record(self.titles.clone())?;
+        let row_len = self.titles.len();
+        if let Some(group) = self.groups.get(0) {
+            for row in &group.rows {
+                let mut values_row: Vec<String> = Vec::with_capacity(row_len);
+                for value in &row.values {
+                    values_row.push(value.to_string());
+                }
+                writer.write_record(values_row)?;
+            }
+        }
+        Ok(String::from_utf8(writer.into_inner()?)?)
+    }
 }

crates/gitql-cli/src/arguments.rs

@@ -1,10 +1,20 @@
+#[derive(Debug, PartialEq)]
+/// Represent the different type of available formats
+pub enum OutputFormat {
+    /// Render the output as table
+    Render,
+    /// Print the output in csv format
+    CSV,
+}
+
 /// Arguments for GitQL
 #[derive(Debug, PartialEq)]
 pub struct Arguments {
     pub repos: Vec<String>,
     pub analysis: bool,
     pub pagination: bool,
     pub page_size: usize,
+    pub output_format: OutputFormat,
 }
 
 /// Create a new instance of Arguments with the default settings
@@ -15,6 +25,7 @@ impl Arguments {
             analysis: false,
             pagination: false,
             page_size: 10,
+            output_format: OutputFormat::Render,
         }
     }
 }
@@ -111,6 +122,24 @@ pub fn parse_arguments(args: &Vec<String>) -> Command {
                 arguments.page_size = page_size;
                 arg_index += 1;
             }
+            "--output" | "-o" => {
+                arg_index += 1;
+                if arg_index >= args_len {
+                    let message = format!("Argument {} must be followed by output format", arg);
+                    return Command::Error(message);
+                }
+
+                let output_type = &args[arg_index].to_lowercase();
+                if output_type == "csv" {
+                    arguments.output_format = OutputFormat::CSV;
+                } else if output_type == "render" {
+                    arguments.output_format = OutputFormat::Render;
+                } else {
+                    return Command::Error("Invalid output format".to_string());
+                }
+
+                arg_index += 1;
+            }
             _ => return Command::Error(format!("Unknown command {}", arg)),
         }
     }
@@ -150,6 +179,7 @@ pub fn print_help_list() {
     println!("-q,  --query <GQL Query>    GitQL query to run on selected repositories");
     println!("-p,  --pagination           Enable print result with pagination");
     println!("-ps, --pagesize             Set pagination page size [default: 10]");
+    println!("-o,  --output               Set output format [render, csv]");
     println!("-a,  --analysis             Print Query analysis");
     println!("-h,  --help                 Print GitQL help");
     println!("-v,  --version              Print GitQL Current Version");
@@ -227,4 +257,26 @@ mod tests {
         let command = parse_arguments(&arguments);
         assert!(matches!(command, Command::Error { .. }));
     }
+
+    #[test]
+    fn test_arguments_with_valid_output_format() {
+        let arguments = vec![
+            "gitql".to_string(),
+            "--output".to_string(),
+            "csv".to_string(),
+        ];
+        let command = parse_arguments(&arguments);
+        assert!(!matches!(command, Command::Error { .. }));
+    }
+
+    #[test]
+    fn test_arguments_with_invalid_output_format() {
+        let arguments = vec![
+            "gitql".to_string(),
+            "--output".to_string(),
+            "text".to_string(),
+        ];
+        let command = parse_arguments(&arguments);
+        assert!(matches!(command, Command::Error { .. }));
+    }
 }

src/main.rs

@@ -3,6 +3,7 @@ use gitql_ast::environment::Environment;
 use gitql_cli::arguments;
 use gitql_cli::arguments::Arguments;
 use gitql_cli::arguments::Command;
+use gitql_cli::arguments::OutputFormat;
 use gitql_cli::diagnostic_reporter;
 use gitql_cli::diagnostic_reporter::DiagnosticReporter;
 use gitql_cli::render;
@@ -150,12 +151,21 @@ fn execute_gitql_query(
     // Render the result only if they are selected groups not any other statement
     let engine_result = evaluation_result.ok().unwrap();
     if let SelectedGroups(mut groups, hidden_selection) = engine_result {
-        render::render_objects(
-            &mut groups,
-            &hidden_selection,
-            arguments.pagination,
-            arguments.page_size,
-        );
+        match arguments.output_format {
+            OutputFormat::Render => {
+                render::render_objects(
+                    &mut groups,
+                    &hidden_selection,
+                    arguments.pagination,
+                    arguments.page_size,
+                );
+            }
+            OutputFormat::CSV => {
+                if let Ok(csv) = groups.as_csv() {
+                    println!("{}", csv);
+                }
+            }
+        }
     }
 
     let engine_duration = engine_start.elapsed();