Support for updating kakoune plugins with kak-plug (#852)

src/steps/kakoune.rs

@@ -0,0 +1,31 @@
+use crate::error::TopgradeError;
+use crate::terminal::print_separator;
+use crate::utils::require;
+use anyhow::Result;
+
+use crate::execution_context::ExecutionContext;
+use crate::executor::ExecutorOutput;
+
+const UPGRADE_KAK: &str = include_str!("upgrade.kak");
+
+pub fn upgrade_kak_plug(ctx: &ExecutionContext) -> Result<()> {
+    let kak = require("kak")?;
+
+    print_separator("Kakoune");
+
+    let mut command = ctx.run_type().execute(&kak);
+    command.args(&["-ui", "dummy", "-e", UPGRADE_KAK]);
+
+    let output = command.output()?;
+
+    if let ExecutorOutput::Wet(output) = output {
+        let status = output.status;
+        if !status.success() {
+            return Err(TopgradeError::ProcessFailed(status).into());
+        } else {
+            println!("Plugins upgraded")
+        }
+    }
+
+    Ok(())
+}