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/zed/src/main.rs

@@ -4,7 +4,7 @@
 mod reliability;
 mod zed;
 
-use anyhow::{Context as _, Result, anyhow};
+use anyhow::{Context as _, Result};
 use clap::{Parser, command};
 use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
 use client::{Client, ProxySettings, UserStore, parse_zed_link};
@@ -1073,7 +1073,7 @@ fn parse_url_arg(arg: &str, cx: &App) -> Result<String> {
             {
                 Ok(arg.into())
             } else {
-                Err(anyhow!("error parsing path argument: {}", error))
+                anyhow::bail!("error parsing path argument: {error}")
             }
         }
     }

crates/zed/src/zed.rs

@@ -421,7 +421,7 @@ fn initialize_panels(
                         workspace.update_in(cx, |workspace, window, cx| {
                             workspace.add_panel(debug_panel, window, cx);
                         })?;
-                        Result::<_, anyhow::Error>::Ok(())
+                        anyhow::Ok(())
                     },
                 )
                 .detach()

crates/zed/src/zed/component_preview.rs

@@ -951,7 +951,7 @@ impl SerializableItem for ComponentPreview {
         item_id: ItemId,
         window: &mut Window,
         cx: &mut App,
-    ) -> Task<gpui::Result<Entity<Self>>> {
+    ) -> Task<anyhow::Result<Entity<Self>>> {
         let deserialized_active_page =
             match COMPONENT_PREVIEW_DB.get_active_page(item_id, workspace_id) {
                 Ok(page) => {
@@ -1009,7 +1009,7 @@ impl SerializableItem for ComponentPreview {
         alive_items: Vec<ItemId>,
         _window: &mut Window,
         cx: &mut App,
-    ) -> Task<gpui::Result<()>> {
+    ) -> Task<anyhow::Result<()>> {
         delete_unloaded_items(
             alive_items,
             workspace_id,
@@ -1026,7 +1026,7 @@ impl SerializableItem for ComponentPreview {
         _closing: bool,
         _window: &mut Window,
         cx: &mut Context<Self>,
-    ) -> Option<Task<gpui::Result<()>>> {
+    ) -> Option<Task<anyhow::Result<()>>> {
         let active_page = self.active_page_id(cx);
         let workspace_id = self.workspace_id?;
         Some(cx.background_spawn(async move {

crates/zed/src/zed/open_listener.rs

@@ -1,6 +1,6 @@
 use crate::handle_open_request;
 use crate::restorable_workspace_locations;
-use anyhow::{Context as _, Result, anyhow};
+use anyhow::{Context as _, Result};
 use cli::{CliRequest, CliResponse, ipc::IpcSender};
 use cli::{IpcHandshake, ipc};
 use client::parse_zed_link;
@@ -74,13 +74,14 @@ impl OpenRequest {
         let url = url::Url::parse(file)?;
         let host = url
             .host()
-            .ok_or_else(|| anyhow!("missing host in ssh url: {}", file))?
+            .with_context(|| format!("missing host in ssh url: {file}"))?
             .to_string();
         let username = Some(url.username().to_string()).filter(|s| !s.is_empty());
         let port = url.port();
-        if !self.open_paths.is_empty() {
-            return Err(anyhow!("cannot open both local and ssh paths"));
-        }
+        anyhow::ensure!(
+            self.open_paths.is_empty(),
+            "cannot open both local and ssh paths"
+        );
         let mut connection_options = SshSettings::get_global(cx).connection_options_for(
             host.clone(),
             port,
@@ -90,9 +91,10 @@ impl OpenRequest {
             connection_options.password = Some(password.to_string());
         }
         if let Some(ssh_connection) = &self.ssh_connection {
-            if *ssh_connection != connection_options {
-                return Err(anyhow!("cannot open multiple ssh connections"));
-            }
+            anyhow::ensure!(
+                *ssh_connection == connection_options,
+                "cannot open multiple ssh connections"
+            );
         }
         self.ssh_connection = Some(connection_options);
         self.parse_file_path(url.path());
@@ -123,7 +125,7 @@ impl OpenRequest {
                 }
             }
         }
-        Err(anyhow!("invalid zed url: {}", request_path))
+        anyhow::bail!("invalid zed url: {request_path}")
     }
 }
 
@@ -141,7 +143,7 @@ impl OpenListener {
     pub fn open_urls(&self, urls: Vec<String>) {
         self.0
             .unbounded_send(urls)
-            .map_err(|_| anyhow!("no listener for open requests"))
+            .context("no listener for open requests")
             .log_err();
     }
 }
@@ -191,7 +193,7 @@ fn connect_to_cli(
                 break;
             }
         }
-        Ok::<_, anyhow::Error>(())
+        anyhow::Ok(())
     });
 
     Ok((async_request_rx, response_tx))
@@ -401,9 +403,7 @@ async fn open_workspaces(
             }
         }
 
-        if errored {
-            return Err(anyhow!("failed to open a workspace"));
-        }
+        anyhow::ensure!(!errored, "failed to open a workspace");
     }
 
     Ok(())