From 1c44de4bba8363e4e711bd49fe01f2a827ba5d02 Mon Sep 17 00:00:00 2001
From: Jonathan Turner <joturner@microsoft.com>
Date: Fri, 17 May 2019 19:30:57 -0700
Subject: [PATCH] Add path completion to existing completions

---
 src/parser/completer.rs |  2 +-
 src/shell/completer.rs  | 65 ++++++++++++++++++++++++-----------------
 src/shell/helper.rs     | 12 ++++----
 3 files changed, 46 insertions(+), 33 deletions(-)

diff --git a/src/parser/completer.rs b/src/parser/completer.rs
index 8591475e6b..f0efbf7519 100644
--- a/src/parser/completer.rs
+++ b/src/parser/completer.rs
@@ -15,7 +15,7 @@ impl completion::Completer for Completer {
         _pos: usize,
         _ctx: &Context<'_>,
     ) -> rustyline::Result<(usize, Vec<completion::Pair>)> {
-        let pairs = self
+        let pairs: Vec<completion::Pair> = self
             .commands
             .keys()
             .map(|k| completion::Pair {
diff --git a/src/shell/completer.rs b/src/shell/completer.rs
index 0f68b3354a..f693aa2740 100644
--- a/src/shell/completer.rs
+++ b/src/shell/completer.rs
@@ -1,26 +1,48 @@
-use rustyline::completion::{Candidate, Completer};
+use rustyline::completion::Completer;
+use rustyline::completion::{self, FilenameCompleter};
 use rustyline::line_buffer::LineBuffer;
 
-#[derive(Debug)]
-crate struct NuCompleter;
+crate struct NuCompleter {
+    pub file_completer: FilenameCompleter,
+}
 
 impl Completer for NuCompleter {
-    type Candidate = NuPair;
+    type Candidate = completion::Pair;
 
     fn complete(
         &self,
-        _line: &str,
-        _pos: usize,
-        _context: &rustyline::Context,
-    ) -> rustyline::Result<(usize, Vec<NuPair>)> {
-        Ok((
-            0,
-            vec![
-                NuPair("exit", "exit"),
-                NuPair("ls", "ls"),
-                NuPair("ps", "ps"),
-            ],
-        ))
+        line: &str,
+        pos: usize,
+        context: &rustyline::Context,
+    ) -> rustyline::Result<(usize, Vec<completion::Pair>)> {
+        let mut pairs = vec![
+            completion::Pair {
+                display: "exit".to_string(),
+                replacement: "exit".to_string(),
+            },
+            completion::Pair {
+                display: "ls".to_string(),
+                replacement: "ls".to_string(),
+            },
+            completion::Pair {
+                display: "ps".to_string(),
+                replacement: "ps".to_string(),
+            },
+        ];
+
+        let mut completions = self.file_completer.complete(line, pos, context)?.1;
+        completions.append(&mut pairs);
+
+        let line_chars: Vec<_> = line.chars().collect();
+        let mut replace_pos = pos;
+        while replace_pos > 0 {
+            if line_chars[replace_pos - 1] == ' ' {
+                break;
+            }
+            replace_pos -= 1;
+        }
+
+        Ok((replace_pos, completions))
     }
 
     fn update(&self, line: &mut LineBuffer, start: usize, elected: &str) {
@@ -28,14 +50,3 @@ impl Completer for NuCompleter {
         line.replace(start..end, elected)
     }
 }
-
-crate struct NuPair(&'static str, &'static str);
-
-impl Candidate for NuPair {
-    fn display(&self) -> &str {
-        self.0
-    }
-    fn replacement(&self) -> &str {
-        self.1
-    }
-}
diff --git a/src/shell/helper.rs b/src/shell/helper.rs
index aaa5bd9f3c..287c5e5b86 100644
--- a/src/shell/helper.rs
+++ b/src/shell/helper.rs
@@ -1,6 +1,6 @@
-use crate::shell::completer::{NuCompleter, NuPair};
+use crate::shell::completer::NuCompleter;
 
-use rustyline::completion::Completer;
+use rustyline::completion::{self, Completer, FilenameCompleter};
 use rustyline::error::ReadlineError;
 use rustyline::highlight::{Highlighter, MatchingBracketHighlighter};
 use rustyline::hint::{Hinter, HistoryHinter};
@@ -15,7 +15,9 @@ crate struct Helper {
 impl Helper {
     crate fn new() -> Helper {
         Helper {
-            completer: NuCompleter,
+            completer: NuCompleter {
+                file_completer: FilenameCompleter::new(),
+            },
             highlighter: MatchingBracketHighlighter::new(),
             hinter: HistoryHinter {},
         }
@@ -23,14 +25,14 @@ impl Helper {
 }
 
 impl Completer for Helper {
-    type Candidate = NuPair;
+    type Candidate = completion::Pair;
 
     fn complete(
         &self,
         line: &str,
         pos: usize,
         ctx: &rustyline::Context<'_>,
-    ) -> Result<(usize, Vec<NuPair>), ReadlineError> {
+    ) -> Result<(usize, Vec<completion::Pair>), ReadlineError> {
         self.completer.complete(line, pos, ctx)
     }
 }