Fix expansion of `~` (#284)

* Fix expansion of `~`, dont use directory relative to cwd.

* Add `expand_tilde`

* Bring back `canonicalize_path`, use `expand_tilde` to `normalize`

* Make `:open ~` completion work

* Fix clippy

* Fold home dir into tilde in Document `realitve_path`

1 files changed, 52 insertions, 9 deletions

diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 254e01b0..fe9c87f7 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -127,6 +127,36 @@ where
     }
 }
 
+/// Expands tilde `~` into users home directory if avilable, otherwise returns the path
+/// unchanged. The tilde will only be expanded when present as the first component of the path
+/// and only slash follows it.
+pub fn expand_tilde(path: &Path) -> PathBuf {
+    let mut components = path.components().peekable();
+    if let Some(Component::Normal(c)) = components.peek() {
+        if c == &"~" {
+            if let Ok(home) = helix_core::home_dir() {
+                // it's ok to unwrap, the path starts with `~`
+                return home.join(path.strip_prefix("~").unwrap());
+            }
+        }
+    }
+
+    path.to_path_buf()
+}
+
+/// Replaces users home directory from `path` with tilde `~` if the directory
+/// is available, otherwise returns the path unchanged.
+pub fn fold_home_dir(path: &Path) -> PathBuf {
+    if let Ok(home) = helix_core::home_dir() {
+        if path.starts_with(&home) {
+            // it's ok to unwrap, the path starts with home dir
+            return PathBuf::from("~").join(path.strip_prefix(&home).unwrap());
+        }
+    }
+
+    path.to_path_buf()
+}
+
 /// Normalize a path, removing things like `.` and `..`.
 ///
 /// CAUTION: This does not resolve symlinks (unlike
@@ -137,6 +167,7 @@ where
 /// needs to improve on.
 /// Copied from cargo: https://github.com/rust-lang/cargo/blob/070e459c2d8b79c5b2ac5218064e7603329c92ae/crates/cargo-util/src/paths.rs#L81
 pub fn normalize_path(path: &Path) -> PathBuf {
+    let path = expand_tilde(path);
     let mut components = path.components().peekable();
     let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
         components.next();
@@ -163,12 +194,17 @@ pub fn normalize_path(path: &Path) -> PathBuf {
     ret
 }
 
-// Returns the canonical, absolute form of a path with all intermediate components normalized.
-//
-// This function is used instead of `std::fs::canonicalize` because we don't want to verify
-// here if the path exists, just normalize it's components.
+/// Returns the canonical, absolute form of a path with all intermediate components normalized.
+///
+/// This function is used instead of `std::fs::canonicalize` because we don't want to verify
+/// here if the path exists, just normalize it's components.
 pub fn canonicalize_path(path: &Path) -> std::io::Result<PathBuf> {
-    std::env::current_dir().map(|current_dir| normalize_path(&current_dir.join(path)))
+    let normalized = normalize_path(path);
+    if normalized.is_absolute() {
+        Ok(normalized)
+    } else {
+        std::env::current_dir().map(|current_dir| current_dir.join(normalized))
+    }
 }
 
 use helix_lsp::lsp;
@@ -709,12 +745,19 @@ impl Document {
         &self.selections[&view_id]
     }
 
-    pub fn relative_path(&self) -> Option<&Path> {
+    pub fn relative_path(&self) -> Option<PathBuf> {
         let cwdir = std::env::current_dir().expect("couldn't determine current directory");
 
-        self.path
-            .as_ref()
-            .map(|path| path.strip_prefix(cwdir).unwrap_or(path))
+        self.path.as_ref().map(|path| {
+            let path = fold_home_dir(path);
+            if path.is_relative() {
+                path
+            } else {
+                path.strip_prefix(cwdir)
+                    .map(|p| p.to_path_buf())
+                    .unwrap_or(path)
+            }
+        })
     }
 
     // pub fn slice<R>(&self, range: R) -> RopeSlice where R: RangeBounds {