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/editor/src/editor.rs

@@ -5552,7 +5552,7 @@ impl Editor {
                 task.await?;
             }
 
-            Ok::<_, anyhow::Error>(())
+            anyhow::Ok(())
         })
         .detach_and_log_err(cx);
     }
@@ -10630,8 +10630,8 @@ impl Editor {
                 .map(|line| {
                     line.strip_prefix(&line_prefix)
                         .or_else(|| line.trim_start().strip_prefix(&line_prefix.trim_start()))
-                        .ok_or_else(|| {
-                            anyhow!("line did not start with prefix {line_prefix:?}: {line:?}")
+                        .with_context(|| {
+                            format!("line did not start with prefix {line_prefix:?}: {line:?}")
                         })
                 })
                 .collect::<Result<Vec<_>, _>>()
@@ -17330,7 +17330,7 @@ impl Editor {
             Err(err) => {
                 let message = format!("Failed to copy permalink: {err}");
 
-                Err::<(), anyhow::Error>(err).log_err();
+                anyhow::Result::<()>::Err(err).log_err();
 
                 if let Some(workspace) = workspace {
                     workspace
@@ -17385,7 +17385,7 @@ impl Editor {
             Err(err) => {
                 let message = format!("Failed to open permalink: {err}");
 
-                Err::<(), anyhow::Error>(err).log_err();
+                anyhow::Result::<()>::Err(err).log_err();
 
                 if let Some(workspace) = workspace {
                     workspace

crates/editor/src/hover_links.rs

@@ -649,7 +649,7 @@ pub fn show_link_definition(
                 }
             })?;
 
-            Ok::<_, anyhow::Error>(())
+            anyhow::Ok(())
         }
         .log_err()
         .await

crates/editor/src/hover_popover.rs

@@ -5,6 +5,7 @@ use crate::{
     hover_links::{InlayHighlight, RangeInEditor},
     scroll::{Autoscroll, ScrollAmount},
 };
+use anyhow::Context as _;
 use gpui::{
     AnyElement, AsyncWindowContext, Context, Entity, Focusable as _, FontWeight, Hsla,
     InteractiveElement, IntoElement, MouseButton, ParentElement, Pixels, ScrollHandle, Size,
@@ -341,7 +342,7 @@ fn show_hover(
                         .and_then(|renderer| {
                             renderer.render_hover(group, point_range, buffer_id, cx)
                         })
-                        .ok_or_else(|| anyhow::anyhow!("no rendered diagnostic"))
+                        .context("no rendered diagnostic")
                 })??;
 
                 let (background_color, border_color) = cx.update(|_, cx| {

crates/editor/src/items.rs

@@ -445,7 +445,7 @@ async fn update_editor_from_message(
             }
 
             multibuffer.remove_excerpts(removed_excerpt_ids, cx);
-            Result::<(), anyhow::Error>::Ok(())
+            anyhow::Ok(())
         })
     })??;
 

crates/editor/src/proposed_changes_editor.rs

@@ -355,7 +355,7 @@ impl Item for ProposedChangesEditor {
         project: Entity<Project>,
         window: &mut Window,
         cx: &mut Context<Self>,
-    ) -> Task<gpui::Result<()>> {
+    ) -> Task<anyhow::Result<()>> {
         self.editor.update(cx, |editor, cx| {
             Item::save(editor, format, project, window, cx)
         })
@@ -488,7 +488,7 @@ impl SemanticsProvider for BranchBufferSemanticsProvider {
         buffer: &Entity<Buffer>,
         position: text::Anchor,
         cx: &mut App,
-    ) -> Option<Task<gpui::Result<Vec<project::DocumentHighlight>>>> {
+    ) -> Option<Task<anyhow::Result<Vec<project::DocumentHighlight>>>> {
         let buffer = self.to_base(&buffer, &[position], cx)?;
         self.0.document_highlights(&buffer, position, cx)
     }
@@ -499,7 +499,7 @@ impl SemanticsProvider for BranchBufferSemanticsProvider {
         position: text::Anchor,
         kind: crate::GotoDefinitionKind,
         cx: &mut App,
-    ) -> Option<Task<gpui::Result<Vec<project::LocationLink>>>> {
+    ) -> Option<Task<anyhow::Result<Vec<project::LocationLink>>>> {
         let buffer = self.to_base(&buffer, &[position], cx)?;
         self.0.definitions(&buffer, position, kind, cx)
     }
@@ -509,7 +509,7 @@ impl SemanticsProvider for BranchBufferSemanticsProvider {
         _: &Entity<Buffer>,
         _: text::Anchor,
         _: &mut App,
-    ) -> Option<Task<gpui::Result<Option<Range<text::Anchor>>>>> {
+    ) -> Option<Task<anyhow::Result<Option<Range<text::Anchor>>>>> {
         None
     }
 
@@ -519,7 +519,7 @@ impl SemanticsProvider for BranchBufferSemanticsProvider {
         _: text::Anchor,
         _: String,
         _: &mut App,
-    ) -> Option<Task<gpui::Result<project::ProjectTransaction>>> {
+    ) -> Option<Task<anyhow::Result<project::ProjectTransaction>>> {
         None
     }
 }