add readonly test

helix-term/tests/test/commands/write.rs

@@ -567,6 +567,43 @@ async fn test_symlink_write() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn test_symlink_write_fail() -> anyhow::Result<()> {
+    #[cfg(unix)]
+    use std::os::unix::fs::symlink;
+    #[cfg(not(unix))]
+    use std::os::windows::fs::symlink_file as symlink;
+
+    let dir = tempfile::tempdir()?;
+
+    let file = helpers::new_readonly_tempfile_in_dir(&dir)?;
+    let symlink_path = dir.path().join("linked");
+    symlink(file.path(), &symlink_path)?;
+
+    let mut app = helpers::AppBuilder::new()
+        .with_file(&symlink_path, None)
+        .build()?;
+
+    test_key_sequence(
+        &mut app,
+        Some("ihello<esc>:wq<ret>"),
+        Some(&|app| {
+            let mut docs: Vec<_> = app.editor.documents().collect();
+            assert_eq!(1, docs.len());
+
+            let doc = docs.pop().unwrap();
+            assert_eq!(Some(&path::normalize(&symlink_path)), doc.path());
+            assert_eq!(&Severity::Error, app.editor.get_status().unwrap().1);
+        }),
+        false,
+    )
+    .await?;
+
+    assert!(symlink_path.is_symlink());
+
+    Ok(())
+}
+
 async fn edit_file_with_content(file_content: &[u8]) -> anyhow::Result<()> {
     let mut file = tempfile::NamedTempFile::new()?;
 

helix-term/tests/test/helpers.rs

@@ -305,6 +305,18 @@ pub fn new_readonly_tempfile() -> anyhow::Result<NamedTempFile> {
     Ok(file)
 }
 
+/// Creates a new temporary file in the directory that is set to read only. Useful for
+/// testing write failures.
+pub fn new_readonly_tempfile_in_dir(
+    dir: impl AsRef<std::path::Path>,
+) -> anyhow::Result<NamedTempFile> {
+    let mut file = tempfile::NamedTempFile::new_in(dir)?;
+    let metadata = file.as_file().metadata()?;
+    let mut perms = metadata.permissions();
+    perms.set_readonly(true);
+    file.as_file_mut().set_permissions(perms)?;
+    Ok(file)
+}
 pub struct AppBuilder {
     args: Args,
     config: Config,

helix-view/src/document.rs

@@ -893,16 +893,16 @@ impl Document {
                     }
                 }
             }
+            let write_path = tokio::fs::read_link(&path)
+                .await
+                .unwrap_or_else(|_| path.clone());
 
-            if readonly(&path) {
+            if readonly(&write_path) {
                 bail!(std::io::Error::new(
                     std::io::ErrorKind::PermissionDenied,
                     "Path is read only"
                 ));
             }
-            let write_path = tokio::fs::read_link(&path)
-                .await
-                .unwrap_or_else(|_| path.clone());
             let backup = if path.exists() {
                 let path_ = write_path.clone();
                 // hacks: we use tempfile to handle the complex task of creating