Add `current` command to retrieve the current Node version (#220)

README.md

@@ -88,6 +88,10 @@ Installs `[VERSION]`. If no version provided, it will install the version specif
 
 Activates `[VERSION]` as the current Node version. If no version provided, it will activate the version specified in the `.nvmrc` or `.node-version` file located in the current working directory.
 
+### `fnm current`
+
+Display currenty activated Node version.
+
 ### `fnm ls`
 
 Lists the installed Node versions.

executable/Current.re

@@ -0,0 +1,11 @@
+open Fnm;
+
+let run = () => {
+  let%lwt currentVersion = Versions.getCurrentVersion();
+  switch (currentVersion) {
+  | Some({name}) => Console.log(name)
+  | _ => Console.log("none")
+  };
+
+  Lwt.return_ok();
+};

executable/FnmApp.re

@@ -14,6 +14,7 @@ module Commands = {
   let exec = (version, useFileVersion, cmd) =>
     Exec.run(~cmd=Array.of_list(cmd), ~version, ~useFileVersion) |> runCmd;
   let use = (version, quiet) => Use.run(~version, ~quiet) |> runCmd;
+  let current = () => Current.run() |> runCmd;
   let alias = (version, name) => Alias.run(~name, ~version) |> runCmd;
   let default = version => Alias.run(~name="default", ~version) |> runCmd;
   let listRemote = version => ListRemote.run(~version) |> runCmd;
@@ -200,6 +201,25 @@ let use = {
   );
 };
 
+let current = {
+  let doc = "Display currently activated version";
+  let sdocs = Manpage.s_common_options;
+  let man = help_secs;
+
+  (
+    Term.(app(const(Commands.current), const())),
+    Term.info(
+      "current",
+      ~envs,
+      ~version,
+      ~doc,
+      ~exits=Term.default_exits,
+      ~man,
+      ~sdocs,
+    ),
+  );
+};
+
 let alias = {
   let doc = "Alias a version";
   let sdocs = Manpage.s_common_options;
@@ -417,6 +437,7 @@ let _ =
     [
       install,
       uninstall,
+      current,
       use,
       alias,
       default,

feature_tests/current/run.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+set -e
+
+PATH="$(pwd)":$PATH # simulating a custom `node`
+
+eval "$(fnm env)"
+
+if [ "$(fnm current)" != "none" ]; then
+  echo "Expected currently activated version is not none!"
+  exit 1
+fi
+
+fnm install v8.11.3
+fnm install v10.10.0
+fnm use v8.11.3
+
+if [ "$(fnm current)" != "v8.11.3" ]; then
+  echo "Expected currently activated version is not v8.11.3!"
+  exit 1
+fi
+
+fnm use v10.10.0
+
+if [ "$(fnm current)" != "v10.10.0" ]; then
+  echo "Expected currently activated version is not v10.10.0!"
+  exit 1
+fi
+
+fnm use system
+
+if [ "$(fnm current)" != "system" ]; then
+  echo "Expected currently activated version is not system!"
+  exit 1
+fi