From 373783d388e420d3b0c7bca15db4d2e9d179c26f Mon Sep 17 00:00:00 2001
From: NotTheDr01ds <32344964+NotTheDr01ds@users.noreply.github.com>
Date: Sun, 15 Sep 2024 14:37:59 -0400
Subject: [PATCH] Deprecate dirs/shells from autoloading rather than removing
 immediately

---
 crates/nu-std/src/lib.rs                 |  12 ++
 crates/nu-std/std/deprecated_dirs/mod.nu | 161 +++++++++++++++++++++++
 crates/nu-std/std/dirs/mod.nu            |  62 +++++----
 crates/nu-std/tests/test_dirs.nu         |   5 +-
 4 files changed, 211 insertions(+), 29 deletions(-)
 create mode 100644 crates/nu-std/std/deprecated_dirs/mod.nu

diff --git a/crates/nu-std/src/lib.rs b/crates/nu-std/src/lib.rs
index 4af23464a6..cc2fff688e 100644
--- a/crates/nu-std/src/lib.rs
+++ b/crates/nu-std/src/lib.rs
@@ -22,6 +22,10 @@ pub fn load_standard_library(
             ("assert", include_str!("../std/assert/mod.nu")),
             ("bench", include_str!("../std/bench/mod.nu")),
             ("dirs", include_str!("../std/dirs/mod.nu")),
+            (
+                "deprecated_dirs",
+                include_str!("../std/deprecated_dirs/mod.nu"),
+            ),
             ("dt", include_str!("../std/dt/mod.nu")),
             ("formats", include_str!("../std/formats/mod.nu")),
             ("help", include_str!("../std/help/mod.nu")),
@@ -52,6 +56,14 @@ pub fn load_standard_library(
         let source = r#"
 # Prelude
 use ([ std core ] | path join) *
+use ([ std deprecated_dirs] | path join) [
+    enter
+    shells
+    g
+    n
+    p
+    dexit
+]
 "#;
 
         let _ = working_set.add_virtual_path(std_dir, VirtualPath::Dir(std_virt_paths));
diff --git a/crates/nu-std/std/deprecated_dirs/mod.nu b/crates/nu-std/std/deprecated_dirs/mod.nu
new file mode 100644
index 0000000000..5590354b84
--- /dev/null
+++ b/crates/nu-std/std/deprecated_dirs/mod.nu
@@ -0,0 +1,161 @@
+# Maintain a list of working directories and navigate them
+
+# The directory stack.
+#
+# Exception: the entry for the current directory contains an
+# irrelevant value. Instead, the source of truth for the working
+# directory is $env.PWD. It has to be this way because cd doesn't
+# know about this module.
+#
+# Example: the following state represents a user-facing directory
+# stack of [/a, /var/tmp, /c], and we are currently in /var/tmp .
+#
+#     PWD = /var/tmp
+#     DIRS_POSITION = 1
+#     DIRS_LIST = [/a, /b, /c]
+#
+# This situation could arise if we started with [/a, /b, /c], then
+# we changed directories from /b to /var/tmp.
+export-env {
+    $env.DIRS_POSITION = 0
+    $env.DIRS_LIST = [($env.PWD | path expand)]
+}
+
+def deprecation_warning [ ] {
+print -e $"
+(ansi red)Warning:(ansi reset) The 'std dirs' module will no longer automatically
+be loaded in the next release. To continue using the Shells
+feature, and to remove this warning, please add the following
+to your config.nu:
+
+use std/dirs aliases *
+
+Or see the documentation for more options.
+"
+}
+
+# Add one or more directories to the list.
+# PWD becomes first of the newly added directories.
+export def --env add [
+    ...paths: string    # directory or directories to add to working list
+] {
+    deprecation_warning
+
+    mut abspaths = []
+    for p in $paths {
+        let exp = ($p | path expand)
+        if ($exp | path type) != 'dir' {
+            let span = (metadata $p).span
+            error make {msg: "not a directory", label: {text: "not a directory", span: $span } }
+        }
+        $abspaths = ($abspaths | append $exp)
+    }
+
+    $env.DIRS_LIST = ($env.DIRS_LIST | insert ($env.DIRS_POSITION + 1) $abspaths | flatten)
+
+    _fetch 1
+}
+
+export alias enter = add
+
+# Advance to the next directory in the list or wrap to beginning.
+export def --env next [
+    N:int = 1   # number of positions to move.
+] {
+    deprecation_warning
+    _fetch $N
+}
+
+export alias n = next
+
+# Back up to the previous directory or wrap to the end.
+export def --env prev [
+    N:int = 1   # number of positions to move.
+] {
+    deprecation_warning
+    _fetch (-1 * $N)
+}
+
+export alias p = prev
+
+# Drop the current directory from the list, if it's not the only one.
+# PWD becomes the next working directory
+export def --env drop [] {
+    deprecation_warning
+    if ($env.DIRS_LIST | length) > 1 {
+        $env.DIRS_LIST = ($env.DIRS_LIST | reject $env.DIRS_POSITION)
+        if ($env.DIRS_POSITION >= ($env.DIRS_LIST | length)) {$env.DIRS_POSITION = 0}
+    }
+
+    # step to previous slot
+    _fetch -1 --forget_current --always_cd
+
+}
+
+export alias dexit = drop
+
+# Display current working directories.
+export def --env show [] {
+    deprecation_warning
+    mut out = []
+    for $p in ($env.DIRS_LIST | enumerate) {
+        let is_act_slot = $p.index == $env.DIRS_POSITION
+        $out = ($out | append [
+            [active, path];
+            [($is_act_slot),
+            (if $is_act_slot {$env.PWD} else {$p.item})   # show current PWD in lieu of active slot
+            ]
+        ])
+    }
+
+    $out
+}
+
+export alias shells = show
+
+export def --env goto [shell?: int] {
+    deprecation_warning
+    if $shell == null {
+        return (show)
+    }
+
+    if $shell < 0 or $shell >= ($env.DIRS_LIST | length) {
+        let span = (metadata $shell | get span)
+        error make {
+            msg: $"(ansi red_bold)invalid_shell_index(ansi reset)"
+            label: {
+                text: $"`shell` should be between 0 and (($env.DIRS_LIST | length) - 1)"
+                span: $span
+            }
+        }
+    }
+
+    _fetch ($shell - $env.DIRS_POSITION)
+}
+
+export alias g = goto
+
+# fetch item helper
+def --env _fetch [
+    offset: int,        # signed change to position
+    --forget_current    # true to skip saving PWD
+    --always_cd         # true to always cd
+] {
+    if not ($forget_current) {
+        # first record current working dir in current slot of ring, to track what CD may have done.
+        $env.DIRS_LIST = ($env.DIRS_LIST | upsert $env.DIRS_POSITION $env.PWD)
+    }
+
+    # figure out which entry to move to
+    # nushell 'mod' operator is really 'remainder', can return negative values.
+    # see: https://stackoverflow.com/questions/13683563/whats-the-difference-between-mod-and-remainder
+    let len = ($env.DIRS_LIST | length)
+    mut pos = ($env.DIRS_POSITION + $offset) mod $len
+    if ($pos < 0) { $pos += $len}
+
+    # if using a different position in ring, CD there.
+    if ($always_cd or $pos != $env.DIRS_POSITION) {
+        $env.DIRS_POSITION = $pos
+        cd ($env.DIRS_LIST | get $pos )
+    }
+}
diff --git a/crates/nu-std/std/dirs/mod.nu b/crates/nu-std/std/dirs/mod.nu
index bf935a84b9..d4596f35fe 100644
--- a/crates/nu-std/std/dirs/mod.nu
+++ b/crates/nu-std/std/dirs/mod.nu
@@ -22,7 +22,8 @@ export-env {
 }
 
 # Add one or more directories to the list.
-# PWD becomes first of the newly added directories.
+# The first directory listed becomes the new
+# active directory.
 export def --env add [
     ...paths: string    # directory or directories to add to working list
     ] {
@@ -38,32 +39,33 @@ export def --env add [
 
         $env.DIRS_LIST = ($env.DIRS_LIST | insert ($env.DIRS_POSITION + 1) $abspaths | flatten)
 
-
     _fetch 1
 }
 
-export alias enter = add
-
-# Advance to the next directory in the list or wrap to beginning.
+# Make the next directory on the list the active directory.
+# If the currenta ctive directory is the last in the list, 
+# then cycle to the top of the list.
 export def --env next [
     N:int = 1   # number of positions to move.
 ] {
     _fetch $N
 }
 
-export alias n = next
-
-# Back up to the previous directory or wrap to the end.
+# Make the previous directory on the list the active directory.
+# If the current active directory is the first in the list, 
+# then cycle to the end of the list.
 export def --env prev [
     N:int = 1   # number of positions to move.
 ] {
     _fetch (-1 * $N)
 }
 
-export alias p = prev
-
-# Drop the current directory from the list, if it's not the only one.
-# PWD becomes the next working directory
+# Drop the current directory from the list.
+# The previous directory in the list becomes
+# the new active directory.
+#
+# If there is only one directory in the list,
+# then this command has no effect.
 export def --env drop [] {
     if ($env.DIRS_LIST | length) > 1 {
         $env.DIRS_LIST = ($env.DIRS_LIST | reject $env.DIRS_POSITION)
@@ -75,10 +77,8 @@ export def --env drop [] {
 
 }
 
-export alias dexit = drop
-
-# Display current working directories.
-export def --env show [] {
+# Display current working directories
+export def --env main [] {
     mut out = []
     for $p in ($env.DIRS_LIST | enumerate) {
         let is_act_slot = $p.index == $env.DIRS_POSITION
@@ -93,29 +93,26 @@ export def --env show [] {
     $out
 }
 
-export alias shells = show
-
-export def --env goto [shell?: int] {
-    if $shell == null {
-        return (show)
+# Jump to directory by index
+export def --env goto [dir_idx?: int] {
+    if $dir_idx == null {
+        return (main)
     }
 
-    if $shell < 0 or $shell >= ($env.DIRS_LIST | length) {
-        let span = (metadata $shell | get span)
+    if $dir_idx < 0 or $dir_idx >= ($env.DIRS_LIST | length) {
+        let span = (metadata $dir_idx | get span)
         error make {
-            msg: $"(ansi red_bold)invalid_shell_index(ansi reset)"
+            msg: $"(ansi red_bold)invalid_dirs_index(ansi reset)"
             label: {
-                text: $"`shell` should be between 0 and (($env.DIRS_LIST | length) - 1)"
+                text: $"`idx` should be between 0 and (($env.DIRS_LIST | length) - 1)"
                 span: $span
             }
         }
     }
 
-    _fetch ($shell - $env.DIRS_POSITION)
+    _fetch ($dir_idx - $env.DIRS_POSITION)
 }
 
-export alias g = goto
-
 # fetch item helper
 def --env _fetch [
     offset: int,        # signed change to position
@@ -140,3 +137,12 @@ def --env _fetch [
         cd ($env.DIRS_LIST | get $pos )
     }
 }
+
+export module aliases {
+    export alias shells = main
+    export alias enter = add
+    export alias dexit = drop
+    export alias p = prev
+    export alias n = next
+    export alias g = goto
+}
\ No newline at end of file
diff --git a/crates/nu-std/tests/test_dirs.nu b/crates/nu-std/tests/test_dirs.nu
index a2b9dcbd46..716ea59936 100644
--- a/crates/nu-std/tests/test_dirs.nu
+++ b/crates/nu-std/tests/test_dirs.nu
@@ -79,7 +79,7 @@ def dirs_command [] {
     assert length $env.DIRS_LIST 2 "drop removes from list"
     assert equal $env.PWD $c.path_b "drop changes PWD to previous in list (before dropped element)"
 
-    assert equal (dirs show) [[active path]; [false $c.base_path] [true $c.path_b]] "show table contains expected information"
+    assert equal (dirs) [[active path]; [false $c.base_path] [true $c.path_b]] "show table contains expected information"
 
     # Stack becomes: [BASE]
     dirs drop
@@ -173,4 +173,7 @@ def dirs_goto [] {
             assert equal $env.PWD ($exp_dir | get $other_pos) "goto changed working directory correctly"
         }
     }
+
+    # check that 'dirs goto' with no argument maps to `dirs` (main)
+    assert length (dirs goto) 3
 }