fix skim-rs#90 escape single quote in preview command

The placeholder in preview command will be replaced by single quoted
selected item. However if the preview command itself includes single
quote, the result won't work.

e.g. command `echo {}` given item `'` would results in `echo '''` that
is not a valid shell command. Unfortunately there is no easy way to
escape single quote in shell.

So we apply the hack: turn single quote `'` to `'\''` that terminate the
first quote and insert an escaped quote and another starting quote.

src/lib.rs

@@ -24,6 +24,7 @@ mod query;
 mod reader;
 mod score;
 mod sender;
+mod util;
 
 use curses::Curses;
 use event::Event::*;

src/model.rs

@@ -18,14 +18,15 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 use unicode_width::UnicodeWidthChar;
 use std::env;
+use util::escape_single_quote;
 
 pub type ClosureType = Box<Fn(&mut Window) + Send>;
 
 const SPINNER_DURATION: u32 = 200;
 const SPINNERS: [char; 8] = ['-', '\\', '|', '/', '-', '\\', '|', '/'];
 
 lazy_static! {
-    static ref RE_FILEDS: Regex = Regex::new(r"(\{-?[0-9.,q]*?})").unwrap();
+    static ref RE_FILEDS: Regex = Regex::new(r"\\?(\{-?[0-9.,q]*?})").unwrap();
     static ref REFRESH_DURATION: Duration = Duration::from_millis(200);
 }
 
@@ -643,13 +644,21 @@ impl Model {
             .expect("model:inject_preview_command: invalid preview command");
         debug!("replace: {:?}, text: {:?}", cmd, text);
         RE_FILEDS.replace_all(cmd, |caps: &Captures| {
+            // \{...
+            if &caps[0][0..1] == "\\" {
+                return caps[0].to_string();
+            }
+
+            // {1..} and other variant
             assert!(caps[1].len() >= 2);
             let range = &caps[1][1..caps[1].len() - 1];
-            if range == "" {
-                format!("'{}'", text)
+            let replacement = if range == "" {
+                text
             } else {
-                format!("'{}'", get_string_by_range(&self.delimiter, text, range).unwrap_or(""))
-            }
+                get_string_by_range(&self.delimiter, text, range).unwrap_or("")
+            };
+
+            format!("'{}'", escape_single_quote(replacement))
         })
     }
 

src/util.rs

@@ -0,0 +1,3 @@
+pub fn escape_single_quote(text: &str) -> String {
+    text.replace("'", "'\\''")
+}

test/test_skim.py

@@ -353,6 +353,7 @@ def test_key_bindings(self):
 
     def test_read0(self):
         self.tmux.send_keys(f"find . | wc -l", Key('Enter'))
+        self.tmux.until(lambda lines: re.search('\d', lines[-1]) is not None)
         lines = self.tmux.capture()
         num_of_files = int(lines[-1])
 
@@ -750,5 +751,23 @@ def test_multiple_option_values_should_be_accepted(self):
         self.tmux.until(lambda lines: lines[-1].startswith('>'))
         self.tmux.send_keys(Key('Enter'))
 
+    def test_single_quote_of_preview_command(self):
+        # echo "'\"ABC\"'" | sk --preview="echo X{}X" => X'"ABC"'X
+        echo_command = '''echo "'\\"ABC\\"'" | '''
+        sk_command = self.sk('--preview=\"echo X{}X\"')
+        command = echo_command + sk_command
+        self.tmux.paste(command)
+        self.tmux.send_keys(Key('Enter'))
+        self.tmux.until(lambda lines: lines.any_include('''X'"ABC"'X'''))
+
+        # echo "'\"ABC\"'" | sk --preview="echo X\{}X" => X{}X
+        echo_command = '''echo "'\\"ABC\\"'" | '''
+        sk_command = self.sk('--preview=\"echo X\\{}X\"')
+        command = echo_command + sk_command
+        self.tmux.paste(command)
+        self.tmux.send_keys(Key('Enter'))
+        self.tmux.until(lambda lines: lines.any_include('''X{}X'''))
+
+
 if __name__ == '__main__':
     unittest.main()