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/assistant_tools/src/edit_agent/evals.rs

@@ -6,7 +6,6 @@ use crate::{
     list_directory_tool::ListDirectoryToolInput,
 };
 use Role::*;
-use anyhow::anyhow;
 use assistant_tool::ToolRegistry;
 use client::{Client, UserStore};
 use collections::HashMap;
@@ -1207,10 +1206,7 @@ impl EvalAssertion {
                 }
             }
 
-            Err(anyhow!(
-                "No score found in response. Raw output: {}",
-                output
-            ))
+            anyhow::bail!("No score found in response. Raw output: {output}");
         })
     }
 

crates/assistant_tools/src/edit_agent/evals/fixtures/delete_run_git_blame/after.rs

@@ -98,21 +98,21 @@ impl BlameEntry {
         let sha = parts
             .next()
             .and_then(|line| line.parse::<Oid>().ok())
-            .ok_or_else(|| anyhow!("failed to parse sha"))?;
+            .with_context(|| format!("parsing sha from {line}"))?;
 
         let original_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse original line number"))?;
+            .with_context(|| format!("parsing original line number from {line}"))?;
         let final_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing final line number from {line}"))?;
 
         let line_count = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing line count from {line}"))?;
 
         let start_line = final_line_number.saturating_sub(1);
         let end_line = start_line + line_count;

crates/assistant_tools/src/edit_agent/evals/fixtures/delete_run_git_blame/before.rs

@@ -80,7 +80,7 @@ async fn run_git_blame(
         .stdout(Stdio::piped())
         .stderr(Stdio::piped())
         .spawn()
-        .map_err(|e| anyhow!("Failed to start git blame process: {}", e))?;
+        .context("starting git blame process")?;
 
     let stdin = child
         .stdin
@@ -92,10 +92,7 @@ async fn run_git_blame(
     }
     stdin.flush().await?;
 
-    let output = child
-        .output()
-        .await
-        .map_err(|e| anyhow!("Failed to read git blame output: {}", e))?;
+    let output = child.output().await.context("reading git blame output")?;
 
     if !output.status.success() {
         let stderr = String::from_utf8_lossy(&output.stderr);
@@ -103,7 +100,7 @@ async fn run_git_blame(
         if trimmed == GIT_BLAME_NO_COMMIT_ERROR || trimmed.contains(GIT_BLAME_NO_PATH) {
             return Ok(String::new());
         }
-        return Err(anyhow!("git blame process failed: {}", stderr));
+        anyhow::bail!("git blame process failed: {stderr}");
     }
 
     Ok(String::from_utf8(output.stdout)?)
@@ -144,21 +141,21 @@ impl BlameEntry {
         let sha = parts
             .next()
             .and_then(|line| line.parse::<Oid>().ok())
-            .ok_or_else(|| anyhow!("failed to parse sha"))?;
+            .with_context(|| format!("parsing sha from {line}"))?;
 
         let original_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse original line number"))?;
+            .with_context(|| format!("parsing original line number from {line}"))?;
         let final_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing final line number from {line}"))?;
 
         let line_count = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing line count from {line}"))?;
 
         let start_line = final_line_number.saturating_sub(1);
         let end_line = start_line + line_count;

crates/assistant_tools/src/edit_agent/evals/fixtures/disable_cursor_blinking/before.rs

@@ -5272,7 +5272,7 @@ impl Editor {
                 task.await?;
             }
 
-            Ok::<_, anyhow::Error>(())
+            anyhow::Ok(())
         })
         .detach_and_log_err(cx);
     }
@@ -10369,8 +10369,8 @@ 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<_>, _>>()
@@ -16944,7 +16944,7 @@ 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
@@ -16999,7 +16999,7 @@ 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/assistant_tools/src/edit_agent/evals/fixtures/extract_handle_command_output/after.rs

@@ -80,7 +80,7 @@ async fn run_git_blame(
         .stdout(Stdio::piped())
         .stderr(Stdio::piped())
         .spawn()
-        .map_err(|e| anyhow!("Failed to start git blame process: {}", e))?;
+        .context("starting git blame process")?;
 
     let stdin = child
         .stdin
@@ -92,10 +92,7 @@ async fn run_git_blame(
     }
     stdin.flush().await?;
 
-    let output = child
-        .output()
-        .await
-        .map_err(|e| anyhow!("Failed to read git blame output: {}", e))?;
+    let output = child.output().await.context("reading git blame output")?;
 
     handle_command_output(output)
 }
@@ -107,7 +104,7 @@ fn handle_command_output(output: std::process::Output) -> Result<String> {
         if trimmed == GIT_BLAME_NO_COMMIT_ERROR || trimmed.contains(GIT_BLAME_NO_PATH) {
             return Ok(String::new());
         }
-        return Err(anyhow!("git blame process failed: {}", stderr));
+        anyhow::bail!("git blame process failed: {stderr}");
     }
 
     Ok(String::from_utf8(output.stdout)?)
@@ -148,21 +145,21 @@ impl BlameEntry {
         let sha = parts
             .next()
             .and_then(|line| line.parse::<Oid>().ok())
-            .ok_or_else(|| anyhow!("failed to parse sha"))?;
+            .with_context(|| format!("parsing sha from {line}"))?;
 
         let original_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse original line number"))?;
+            .with_context(|| format!("parsing original line number from {line}"))?;
         let final_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing final line number from {line}"))?;
 
         let line_count = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing line count from {line}"))?;
 
         let start_line = final_line_number.saturating_sub(1);
         let end_line = start_line + line_count;

crates/assistant_tools/src/edit_agent/evals/fixtures/extract_handle_command_output/before.rs

@@ -80,7 +80,7 @@ async fn run_git_blame(
         .stdout(Stdio::piped())
         .stderr(Stdio::piped())
         .spawn()
-        .map_err(|e| anyhow!("Failed to start git blame process: {}", e))?;
+        .context("starting git blame process")?;
 
     let stdin = child
         .stdin
@@ -92,10 +92,7 @@ async fn run_git_blame(
     }
     stdin.flush().await?;
 
-    let output = child
-        .output()
-        .await
-        .map_err(|e| anyhow!("Failed to read git blame output: {}", e))?;
+    let output = child.output().await.context("reading git blame output")?;
 
     if !output.status.success() {
         let stderr = String::from_utf8_lossy(&output.stderr);
@@ -103,7 +100,7 @@ async fn run_git_blame(
         if trimmed == GIT_BLAME_NO_COMMIT_ERROR || trimmed.contains(GIT_BLAME_NO_PATH) {
             return Ok(String::new());
         }
-        return Err(anyhow!("git blame process failed: {}", stderr));
+        anyhow::bail!("git blame process failed: {stderr}");
     }
 
     Ok(String::from_utf8(output.stdout)?)
@@ -144,21 +141,21 @@ impl BlameEntry {
         let sha = parts
             .next()
             .and_then(|line| line.parse::<Oid>().ok())
-            .ok_or_else(|| anyhow!("failed to parse sha"))?;
+            .with_context(|| format!("parsing sha from {line}"))?;
 
         let original_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse original line number"))?;
+            .with_context(|| format!("parsing original line number from {line}"))?;
         let final_line_number = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing final line number from {line}"))?;
 
         let line_count = parts
             .next()
             .and_then(|line| line.parse::<u32>().ok())
-            .ok_or_else(|| anyhow!("Failed to parse final line number"))?;
+            .with_context(|| format!("parsing line count from {line}"))?;
 
         let start_line = final_line_number.saturating_sub(1);
         let end_line = start_line + line_count;

crates/assistant_tools/src/edit_agent/evals/fixtures/use_wasi_sdk_in_compile_parser_to_wasm/before.rs

@@ -20,7 +20,7 @@ use std::{
 
 #[cfg(any(feature = "tree-sitter-highlight", feature = "tree-sitter-tags"))]
 use anyhow::Error;
-use anyhow::{Context, Result, anyhow};
+use anyhow::{Context as _, Result, anyhow};
 use etcetera::BaseStrategy as _;
 use fs4::fs_std::FileExt;
 use indoc::indoc;
@@ -875,16 +875,13 @@ impl Loader {
 
         FileExt::unlock(lock_file)?;
         fs::remove_file(lock_path)?;
-
-        if output.status.success() {
-            Ok(())
-        } else {
-            Err(anyhow!(
-                "Parser compilation failed.\nStdout: {}\nStderr: {}",
-                String::from_utf8_lossy(&output.stdout),
-                String::from_utf8_lossy(&output.stderr)
-            ))
-        }
+        anyhow::ensure!(
+            output.status.success(),
+            "Parser compilation failed.\nStdout: {}\nStderr: {}",
+            String::from_utf8_lossy(&output.stdout),
+            String::from_utf8_lossy(&output.stderr)
+        );
+        Ok(())
     }
 
     #[cfg(unix)]
@@ -941,17 +938,13 @@ impl Loader {
                         .map(|f| format!("  `{f}`"))
                         .collect::<Vec<_>>()
                         .join("\n");
+                    anyhow::bail!(format!(indoc! {"
+                        Missing required functions in the external scanner, parsing won't work without these!
 
-                    return Err(anyhow!(format!(
-                        indoc! {"
-                            Missing required functions in the external scanner, parsing won't work without these!
+                        {missing}
 
-                            {}
-
-                            You can read more about this at https://tree-sitter.github.io/tree-sitter/creating-parsers/4-external-scanners
-                        "},
-                        missing,
-                    )));
+                        You can read more about this at https://tree-sitter.github.io/tree-sitter/creating-parsers/4-external-scanners
+                    "}));
                 }
             }
         }
@@ -1008,9 +1001,9 @@ impl Loader {
         {
             EmccSource::Podman
         } else {
-            return Err(anyhow!(
+            anyhow::bail!(
                 "You must have either emcc, docker, or podman on your PATH to run this command"
-            ));
+            );
         };
 
         let mut command = match source {
@@ -1103,12 +1096,11 @@ impl Loader {
             .spawn()
             .with_context(|| "Failed to run emcc command")?
             .wait()?;
-        if !status.success() {
-            return Err(anyhow!("emcc command failed"));
-        }
-
-        fs::rename(src_path.join(output_name), output_path)
-            .context("failed to rename wasm output file")?;
+        anyhow::ensure!(status.success(), "emcc command failed");
+        let source_path = src_path.join(output_name);
+        fs::rename(&source_path, &output_path).with_context(|| {
+            format!("failed to rename wasm output file from {source_path:?} to {output_path:?}")
+        })?;
 
         Ok(())
     }
@@ -1185,11 +1177,8 @@ impl Loader {
                                     .map(|path| {
                                        let path = parser_path.join(path);
                                         // prevent p being above/outside of parser_path
-                                        if path.starts_with(parser_path) {
-                                            Ok(path)
-                                        } else {
-                                            Err(anyhow!("External file path {path:?} is outside of parser directory {parser_path:?}"))
-                                        }
+                                        anyhow::ensure!(path.starts_with(parser_path), "External file path {path:?} is outside of parser directory {parser_path:?}");
+                                        Ok(path)
                                     })
                                     .collect::<Result<Vec<_>>>()
                             }).transpose()?,
@@ -1324,11 +1313,8 @@ impl Loader {
         let name = GRAMMAR_NAME_REGEX
             .captures(&first_three_lines)
             .and_then(|c| c.get(1))
-            .ok_or_else(|| {
-                anyhow!(
-                    "Failed to parse the language name from grammar.json at {}",
-                    grammar_path.display()
-                )
+            .with_context(|| {
+                format!("Failed to parse the language name from grammar.json at {grammar_path:?}")
             })?;
 
         Ok(name.as_str().to_string())
@@ -1347,7 +1333,7 @@ impl Loader {
             {
                 Ok(config.0)
             } else {
-                Err(anyhow!("Unknown scope '{scope}'"))
+                anyhow::bail!("Unknown scope '{scope}'")
             }
         } else if let Some((lang, _)) = self
             .language_configuration_for_file_name(path)
@@ -1371,7 +1357,7 @@ impl Loader {
         } else if let Some(lang) = self.language_configuration_for_first_line_regex(path)? {
             Ok(lang.0)
         } else {
-            Err(anyhow!("No language found"))
+            anyhow::bail!("No language found");
         }
     }