From ae765c71fd5391c1507b57fa6836994fd113468e Mon Sep 17 00:00:00 2001
From: pwygab <88221256+merelymyself@users.noreply.github.com>
Date: Wed, 20 Jul 2022 01:39:50 +0800
Subject: [PATCH] add config option to limit external command completions
 (#6076)

* add config option to limit external command completions

* fmt

* small change

* change name in config

* change name in config again
---
 .../src/completions/command_completions.rs    | 26 ++++++++++---------
 crates/nu-protocol/src/config.rs              |  9 +++++++
 docs/sample_config/default_config.nu          |  1 +
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/crates/nu-cli/src/completions/command_completions.rs b/crates/nu-cli/src/completions/command_completions.rs
index 891716663f..e1cdbfba52 100644
--- a/crates/nu-cli/src/completions/command_completions.rs
+++ b/crates/nu-cli/src/completions/command_completions.rs
@@ -43,19 +43,21 @@ impl CommandCompletion {
 
                     if let Ok(mut contents) = std::fs::read_dir(path) {
                         while let Some(Ok(item)) = contents.next() {
-                            if !executables.contains(
-                                &item
-                                    .path()
-                                    .file_name()
-                                    .map(|x| x.to_string_lossy().to_string())
-                                    .unwrap_or_default(),
-                            ) && matches!(
-                                item.path()
-                                    .file_name()
-                                    .map(|x| match_algorithm
+                            if self.engine_state.config.max_external_completion_results
+                                > executables.len() as i64
+                                && !executables.contains(
+                                    &item
+                                        .path()
+                                        .file_name()
+                                        .map(|x| x.to_string_lossy().to_string())
+                                        .unwrap_or_default(),
+                                )
+                                && matches!(
+                                    item.path().file_name().map(|x| match_algorithm
                                         .matches_str(&x.to_string_lossy(), prefix)),
-                                Some(true)
-                            ) && is_executable::is_executable(&item.path())
+                                    Some(true)
+                                )
+                                && is_executable::is_executable(&item.path())
                             {
                                 if let Ok(name) = item.file_name().into_string() {
                                     executables.push(name);
diff --git a/crates/nu-protocol/src/config.rs b/crates/nu-protocol/src/config.rs
index dd76036404..03f104142a 100644
--- a/crates/nu-protocol/src/config.rs
+++ b/crates/nu-protocol/src/config.rs
@@ -59,6 +59,7 @@ pub struct Config {
     pub use_grid_icons: bool,
     pub footer_mode: FooterMode,
     pub float_precision: i64,
+    pub max_external_completion_results: i64,
     pub filesize_format: String,
     pub use_ansi_coloring: bool,
     pub quick_completions: bool,
@@ -92,6 +93,7 @@ impl Default for Config {
             use_grid_icons: false,
             footer_mode: FooterMode::RowCount(25),
             float_precision: 4,
+            max_external_completion_results: 100,
             filesize_format: "auto".into(),
             use_ansi_coloring: true,
             quick_completions: true,
@@ -249,6 +251,13 @@ impl Value {
                             eprintln!("$config.partial_completions is not a bool")
                         }
                     }
+                    "max_external_completion_results" => {
+                        if let Ok(i) = value.as_integer() {
+                            config.max_external_completion_results = i;
+                        } else {
+                            eprintln!("$config.max_external_completion_results is not an integer")
+                        }
+                    }
                     "completion_algorithm" => {
                         if let Ok(v) = value.as_string() {
                             config.completion_algorithm = v.to_lowercase();
diff --git a/docs/sample_config/default_config.nu b/docs/sample_config/default_config.nu
index 42276f22f9..e156b10f00 100644
--- a/docs/sample_config/default_config.nu
+++ b/docs/sample_config/default_config.nu
@@ -256,6 +256,7 @@ let-env config = {
   cd_with_abbreviations: false # set to true to allow you to do things like cd s/o/f and nushell expand it to cd some/other/folder
   case_sensitive_completions: false # set to true to enable case-sensitive completions
   enable_external_completion: true # set to false to prevent nushell looking into $env.PATH to find more suggestions, `false` recommended for WSL users as this look up my be very slow
+  max_external_completion_results: 100 # setting it lower can improve completion performance at the cost of omitting some options
 
   # A strategy of managing table view in case of limited space.
   table_trim: {