Always save history, add history command

src/commands/history.rs

@@ -0,0 +1,49 @@
+use crate::cli::History as HistoryFile;
+use crate::commands::PerItemCommand;
+use crate::errors::ShellError;
+use crate::parser::registry::{self};
+use crate::prelude::*;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+pub struct History;
+
+impl PerItemCommand for History {
+    fn name(&self) -> &str {
+        "history"
+    }
+
+    fn signature(&self) -> registry::Signature {
+        Signature::build("history")
+    }
+
+    fn usage(&self) -> &str {
+        "Display command history."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        _input: Tagged<Value>,
+    ) -> Result<OutputStream, ShellError> {
+        let tag = call_info.name_tag.clone();
+
+        let stream = async_stream! {
+            let history_path = HistoryFile::path();
+            let file = File::open(history_path);
+            if let Ok(file) = file {
+                let reader = BufReader::new(file);
+                for line in reader.lines() {
+                    if let Ok(line) = line {
+                        yield ReturnSuccess::value(Value::string(line).tagged(tag.clone()));
+                    }
+                }
+            } else {
+                yield Err(ShellError::labeled_error("Could not open history", "history file could not be opened", tag.clone()));
+            }
+        };
+        Ok(stream.to_output_stream())
+    }
+}