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/debugger_ui/src/debugger_panel.rs

@@ -7,7 +7,7 @@ use crate::{
     ShowStackTrace, StepBack, StepInto, StepOut, StepOver, Stop, ToggleIgnoreBreakpoints,
     persistence,
 };
-use anyhow::{Result, anyhow};
+use anyhow::{Context as _, Result, anyhow};
 use command_palette_hooks::CommandPaletteFilter;
 use dap::StartDebuggingRequestArguments;
 use dap::adapters::DebugAdapterName;
@@ -1021,17 +1021,13 @@ impl DebugPanel {
                     }
 
                     workspace.update(cx, |workspace, cx| {
-                        if let Some(project_path) = workspace
+                        workspace
                             .project()
                             .read(cx)
                             .project_path_for_absolute_path(&path, cx)
-                        {
-                            Ok(project_path)
-                        } else {
-                            Err(anyhow!(
-                                "Couldn't get project path for .zed/debug.json in active worktree"
-                            ))
-                        }
+                            .context(
+                                "Couldn't get project path for .zed/debug.json in active worktree",
+                            )
                     })?
                 })
             })

crates/debugger_ui/src/new_session_modal.rs

@@ -9,7 +9,6 @@ use std::{
     usize,
 };
 
-use anyhow::Result;
 use dap::{
     DapRegistry, DebugRequest,
     adapters::{DebugAdapterName, DebugTaskDefinition},
@@ -253,7 +252,7 @@ impl NewSessionModal {
                 cx.emit(DismissEvent);
             })
             .ok();
-            Result::<_, anyhow::Error>::Ok(())
+            anyhow::Ok(())
         })
         .detach_and_log_err(cx);
     }

crates/debugger_ui/src/persistence.rs

@@ -1,3 +1,4 @@
+use anyhow::Context as _;
 use collections::HashMap;
 use dap::{Capabilities, adapters::DebugAdapterName};
 use db::kvp::KEY_VALUE_STORE;
@@ -96,18 +97,14 @@ pub(crate) async fn serialize_pane_layout(
     adapter_name: DebugAdapterName,
     pane_group: SerializedLayout,
 ) -> anyhow::Result<()> {
-    if let Ok(serialized_pane_group) = serde_json::to_string(&pane_group) {
-        KEY_VALUE_STORE
-            .write_kvp(
-                format!("{DEBUGGER_PANEL_PREFIX}-{adapter_name}"),
-                serialized_pane_group,
-            )
-            .await
-    } else {
-        Err(anyhow::anyhow!(
-            "Failed to serialize pane group with serde_json as a string"
-        ))
-    }
+    let serialized_pane_group = serde_json::to_string(&pane_group)
+        .context("Serializing pane group with serde_json as a string")?;
+    KEY_VALUE_STORE
+        .write_kvp(
+            format!("{DEBUGGER_PANEL_PREFIX}-{adapter_name}"),
+            serialized_pane_group,
+        )
+        .await
 }
 
 pub(crate) fn build_serialized_layout(

crates/debugger_ui/src/session.rs

@@ -196,7 +196,7 @@ impl FollowableItem for DebugSession {
         _state: &mut Option<proto::view::Variant>,
         _window: &mut Window,
         _cx: &mut App,
-    ) -> Option<gpui::Task<gpui::Result<Entity<Self>>>> {
+    ) -> Option<gpui::Task<anyhow::Result<Entity<Self>>>> {
         None
     }
 
@@ -218,7 +218,7 @@ impl FollowableItem for DebugSession {
         _message: proto::update_view::Variant,
         _window: &mut Window,
         _cx: &mut Context<Self>,
-    ) -> gpui::Task<gpui::Result<()>> {
+    ) -> gpui::Task<anyhow::Result<()>> {
         Task::ready(Ok(()))
     }
 

crates/debugger_ui/src/session/running.rs

@@ -10,7 +10,7 @@ use std::{any::Any, ops::ControlFlow, path::PathBuf, sync::Arc, time::Duration};
 use crate::persistence::{self, DebuggerPaneItem, SerializedLayout};
 
 use super::DebugPanelItemEvent;
-use anyhow::{Result, anyhow};
+use anyhow::{Context as _, Result, anyhow};
 use breakpoint_list::BreakpointList;
 use collections::{HashMap, IndexMap};
 use console::Console;
@@ -817,7 +817,7 @@ impl RunningState {
                 let exit_status = terminal
                     .read_with(cx, |terminal, cx| terminal.wait_for_completed_task(cx))?
                     .await
-                    .ok_or_else(|| anyhow!("Failed to wait for completed task"))?;
+                    .context("Failed to wait for completed task")?;
 
                 if !exit_status.success() {
                     anyhow::bail!("Build failed");
@@ -829,22 +829,22 @@ impl RunningState {
             let request = if let Some(request) = request {
                 request
             } else if let Some((task, locator_name)) = build_output {
-                let locator_name = locator_name
-                    .ok_or_else(|| anyhow!("Could not find a valid locator for a build task"))?;
+                let locator_name =
+                    locator_name.context("Could not find a valid locator for a build task")?;
                 dap_store
                     .update(cx, |this, cx| {
                         this.run_debug_locator(&locator_name, task, cx)
                     })?
                     .await?
             } else {
-                return Err(anyhow!("No request or build provided"));
+                anyhow::bail!("No request or build provided");
             };
             let request = match request {
                 dap::DebugRequest::Launch(launch_request) => {
                     let cwd = match launch_request.cwd.as_deref().and_then(|path| path.to_str()) {
                         Some(cwd) => {
                             let substituted_cwd = substitute_variables_in_str(&cwd, &task_context)
-                                .ok_or_else(|| anyhow!("Failed to substitute variables in cwd"))?;
+                                .context("substituting variables in cwd")?;
                             Some(PathBuf::from(substituted_cwd))
                         }
                         None => None,
@@ -854,7 +854,7 @@ impl RunningState {
                         &launch_request.env.into_iter().collect(),
                         &task_context,
                     )
-                    .ok_or_else(|| anyhow!("Failed to substitute variables in env"))?
+                    .context("substituting variables in env")?
                     .into_iter()
                     .collect();
                     let new_launch_request = LaunchRequest {
@@ -862,13 +862,13 @@ impl RunningState {
                             &launch_request.program,
                             &task_context,
                         )
-                        .ok_or_else(|| anyhow!("Failed to substitute variables in program"))?,
+                        .context("substituting variables in program")?,
                         args: launch_request
                             .args
                             .into_iter()
                             .map(|arg| substitute_variables_in_str(&arg, &task_context))
                             .collect::<Option<Vec<_>>>()
-                            .ok_or_else(|| anyhow!("Failed to substitute variables in args"))?,
+                            .context("substituting variables in args")?,
                         cwd,
                         env,
                     };
@@ -994,7 +994,7 @@ impl RunningState {
                     .pty_info
                     .pid()
                     .map(|pid| pid.as_u32())
-                    .ok_or_else(|| anyhow!("Terminal was spawned but PID was not available"))
+                    .context("Terminal was spawned but PID was not available")
             })?
         });
 

crates/debugger_ui/src/session/running/breakpoint_list.rs

@@ -377,7 +377,7 @@ impl LineBreakpoint {
                                         })
                                         .ok();
                                 }
-                                Result::<_, anyhow::Error>::Ok(())
+                                anyhow::Ok(())
                             })
                             .detach();
 

crates/debugger_ui/src/session/running/console.rs

@@ -278,7 +278,7 @@ impl CompletionProvider for ConsoleQueryBarCompletionProvider {
         _completion_indices: Vec<usize>,
         _completions: Rc<RefCell<Box<[Completion]>>>,
         _cx: &mut Context<Editor>,
-    ) -> gpui::Task<gpui::Result<bool>> {
+    ) -> gpui::Task<anyhow::Result<bool>> {
         Task::ready(Ok(false))
     }
 
@@ -289,7 +289,7 @@ impl CompletionProvider for ConsoleQueryBarCompletionProvider {
         _completion_index: usize,
         _push_to_history: bool,
         _cx: &mut Context<Editor>,
-    ) -> gpui::Task<gpui::Result<Option<language::Transaction>>> {
+    ) -> gpui::Task<anyhow::Result<Option<language::Transaction>>> {
         Task::ready(Ok(None))
     }
 

crates/debugger_ui/src/session/running/stack_frame_list.rs

@@ -2,7 +2,7 @@ use std::path::Path;
 use std::sync::Arc;
 use std::time::Duration;
 
-use anyhow::{Result, anyhow};
+use anyhow::{Context as _, Result, anyhow};
 use dap::StackFrameId;
 use gpui::{
     AnyElement, Entity, EventEmitter, FocusHandle, Focusable, MouseButton, ScrollStrategy,
@@ -285,9 +285,10 @@ impl StackFrameList {
             })?;
             this.update_in(cx, |this, window, cx| {
                 this.workspace.update(cx, |workspace, cx| {
-                    let project_path = buffer.read(cx).project_path(cx).ok_or_else(|| {
-                        anyhow!("Could not select a stack frame for unnamed buffer")
-                    })?;
+                    let project_path = buffer
+                        .read(cx)
+                        .project_path(cx)
+                        .context("Could not select a stack frame for unnamed buffer")?;
 
                     let open_preview = !workspace
                         .item_of_type::<StackTraceView>(cx)
@@ -312,9 +313,9 @@ impl StackFrameList {
             .await?;
 
             this.update(cx, |this, cx| {
-                let Some(thread_id) = this.state.read_with(cx, |state, _| state.thread_id)? else {
-                    return Err(anyhow!("No selected thread ID found"));
-                };
+                let thread_id = this.state.read_with(cx, |state, _| {
+                    state.thread_id.context("No selected thread ID found")
+                })??;
 
                 this.workspace.update(cx, |workspace, cx| {
                     let breakpoint_store = workspace.project().read(cx).breakpoint_store();

crates/debugger_ui/src/tests.rs

@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use anyhow::{Result, anyhow};
+use anyhow::{Context as _, Result};
 use dap::adapters::DebugTaskDefinition;
 use dap::{DebugRequest, client::DebugAdapterClient};
 use gpui::{Entity, TestAppContext, WindowHandle};
@@ -125,7 +125,7 @@ pub fn start_debug_session_with<T: Fn(&Arc<DebugAdapterClient>) + 'static>(
             .and_then(|panel| panel.read(cx).active_session())
             .map(|session| session.read(cx).running_state().read(cx).session())
             .cloned()
-            .ok_or_else(|| anyhow!("Failed to get active session"))
+            .context("Failed to get active session")
     })??;
 
     Ok(session)