Use anyhow more idiomatically (#31052)

https://github.com/zed-industries/zed/issues/30972 brought up another
case where our context is not enough to track the actual source of the
issue: we get a general top-level error without inner error.

The reason for this was `.ok_or_else(|| anyhow!("failed to read HEAD
SHA"))?; ` on the top level.

The PR finally reworks the way we use anyhow to reduce such issues (or
at least make it simpler to bubble them up later in a fix).
On top of that, uses a few more anyhow methods for better readability.

* `.ok_or_else(|| anyhow!("..."))`, `map_err` and other similar error
conversion/option reporting cases are replaced with `context` and
`with_context` calls
* in addition to that, various `anyhow!("failed to do ...")` are
stripped with `.context("Doing ...")` messages instead to remove the
parasitic `failed to` text
* `anyhow::ensure!` is used instead of `if ... { return Err(...); }`
calls
* `anyhow::bail!` is used instead of `return Err(anyhow!(...));`

Release Notes:

- N/A

crates/project_panel/src/project_panel.rs

@@ -1,7 +1,7 @@
 mod project_panel_settings;
 mod utils;
 
-use anyhow::{Context as _, Result, anyhow};
+use anyhow::{Context as _, Result};
 use client::{ErrorCode, ErrorExt};
 use collections::{BTreeSet, HashMap, hash_map};
 use command_palette_hooks::CommandPaletteFilter;
@@ -603,7 +603,7 @@ impl ProjectPanel {
             Some(serialization_key) => cx
                 .background_spawn(async move { KEY_VALUE_STORE.read_kvp(&serialization_key) })
                 .await
-                .map_err(|e| anyhow!("Failed to load project panel: {}", e))
+                .context("loading project panel")
                 .log_err()
                 .flatten()
                 .map(|panel| serde_json::from_str::<SerializedProjectPanel>(&panel))
@@ -2304,7 +2304,7 @@ impl ProjectPanel {
                             project_panel
                                 .project
                                 .update(cx, |project, cx| project.delete_entry(entry_id, true, cx))
-                                .ok_or_else(|| anyhow!("no such entry"))
+                                .context("no such entry")
                         })??
                         .await?;
                 }
@@ -4465,34 +4465,30 @@ impl ProjectPanel {
         skip_ignored: bool,
         cx: &mut Context<Self>,
     ) -> Result<()> {
-        if let Some(worktree) = project.read(cx).worktree_for_entry(entry_id, cx) {
-            let worktree = worktree.read(cx);
-            if skip_ignored
-                && worktree
-                    .entry_for_id(entry_id)
-                    .map_or(true, |entry| entry.is_ignored && !entry.is_always_included)
-            {
-                return Err(anyhow!(
-                    "can't reveal an ignored entry in the project panel"
-                ));
-            }
-
-            let worktree_id = worktree.id();
-            self.expand_entry(worktree_id, entry_id, cx);
-            self.update_visible_entries(Some((worktree_id, entry_id)), cx);
-            self.marked_entries.clear();
-            self.marked_entries.insert(SelectedEntry {
-                worktree_id,
-                entry_id,
-            });
-            self.autoscroll(cx);
-            cx.notify();
-            Ok(())
-        } else {
-            Err(anyhow!(
-                "can't reveal a non-existent entry in the project panel"
-            ))
+        let worktree = project
+            .read(cx)
+            .worktree_for_entry(entry_id, cx)
+            .context("can't reveal a non-existent entry in the project panel")?;
+        let worktree = worktree.read(cx);
+        if skip_ignored
+            && worktree
+                .entry_for_id(entry_id)
+                .map_or(true, |entry| entry.is_ignored && !entry.is_always_included)
+        {
+            anyhow::bail!("can't reveal an ignored entry in the project panel");
         }
+
+        let worktree_id = worktree.id();
+        self.expand_entry(worktree_id, entry_id, cx);
+        self.update_visible_entries(Some((worktree_id, entry_id)), cx);
+        self.marked_entries.clear();
+        self.marked_entries.insert(SelectedEntry {
+            worktree_id,
+            entry_id,
+        });
+        self.autoscroll(cx);
+        cx.notify();
+        Ok(())
     }
 
     fn find_active_indent_guide(

crates/project_panel/src/project_panel_tests.rs

@@ -5268,7 +5268,7 @@ impl project::ProjectItem for TestProjectItem {
         _project: &Entity<Project>,
         path: &ProjectPath,
         cx: &mut App,
-    ) -> Option<Task<gpui::Result<Entity<Self>>>> {
+    ) -> Option<Task<anyhow::Result<Entity<Self>>>> {
         let path = path.clone();
         Some(cx.spawn(async move |cx| cx.new(|_| Self { path })))
     }