White space at the end of variables is sometimes trimmed

[certik]

Specifically this then causes to not have space in the prompt when you change it.

$ echo "X${PS1}X"
X{display_cwd}{git_branch}$X
$ PS1="$PS1"
$ls

As you can see, it seems $PS1 trims the space at the end, and then it is missing in the prompt. There might be more than one bug in this. We need to ensure that spaces at the end of the string are preserved.

[certik]

With the following diff:

--- a/crates/deno_task_shell/src/shell/execute.rs
+++ b/crates/deno_task_shell/src/shell/execute.rs
@@ -1470,6 +1470,7 @@ fn evaluate_word_parts(
             } else if let Some(val) =
               state.get_var(&name).map(|v| v.to_string())
             {
+                println!("Variable: {}.", val);
               Ok(Some(val.into()))
             } else {
               Err(miette::miette!("Undefined variable: {}", name))
@@ -1533,11 +1534,13 @@ fn evaluate_word_parts(
         };

         if let Ok(Some(text)) = evaluation_result_text {
+            println!("text: {:?}.", text);
           let mut parts = text.into_parts();

           if !parts.is_empty() {
             // append the first part to the current text
             let first_part = parts.remove(0);
+            println!("parts: {:?}.", first_part);
             current_text.push(first_part);

             if !parts.is_empty() {

we get:

$ echo "X${PS1}X"
Variable: {display_cwd}{git_branch}$ .
text: Text { parts: [Text("{display_cwd}{git_branch}$")] }.
parts: Text("{display_cwd}{git_branch}$").
X{display_cwd}{git_branch}$X

So the val is still good with a space at the end, but text is already bad. Further debugging with

+                println!("Variable2: {:?}.", <String as Into<Text>>::into(val.clone()));

shows that it's val.into() that removes the space.

The PR #216 almost fixes it, at least it shows where the problem is.

[certik]

I discovered another problem:

~/repos/shell(main)$ X="a   a"
~/repos/shell(main)$ echo $X
a a

It will remove multiple spaces and just use one space.