Github Actions improvements for write-rustdoc-hide-lines (v2) (#1101)

write-rustdoc-hide-lines/src/main.rs

@@ -1,30 +1,6 @@
 use std::{env, path::PathBuf, process::ExitCode};
 use write_rustdoc_hide_lines::formatter;
 
-/// Generates `hide_lines` annotations to Rust code blocks.
-///
-/// In most cases you can just call `write_rustdoc_hide_lines.sh`, which will automatically handle
-/// formatting all files.
-///
-/// ```shell
-/// $ cd write-rustdoc-hide-lines
-/// $ ./write_rustdoc_hide_lines.sh
-/// ```
-///
-/// You can also run the executable manually.
-///
-/// ```shell
-/// $ cd write-rustdoc-hide-lines
-///
-/// # Format one folder.
-/// $ cargo run -- format ../content/learn/book
-///
-/// # Format multiple folders.
-/// $ cargo run -- format ../content/learn/book ../content/learn/quick-start
-///
-/// # Check one folder, but don't overwrite it.
-/// $ cargo run -- check ../content/learn/book
-/// ```
 fn main() -> ExitCode {
     // The first argument is usually the executable path, so we skip that to just get arguments.
     let mut args = env::args().skip(1);
@@ -55,28 +31,55 @@ fn check(folders: impl Iterator<Item = PathBuf> + ExactSizeIterator) -> ExitCode
     // An aggregate list of all unformatted files, empty by default.
     let mut unformatted_files = Vec::new();
 
+    // Detect if we're running through Github Actions or not.
+    // https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables
+    let is_ci = env::var("GITHUB_ACTIONS").is_ok_and(|x| x == "true");
+
     for folder in folders {
-        println!("\nChecking folder {:?}", folder);
+        if is_ci {
+            // Create an collapsible group for all files checked.
+            // https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#grouping-log-lines
+            println!("::group::Checking folder {:?}", folder);
+        } else {
+            println!("\nChecking folder {:?}", folder);
+        }
 
         // Checks folders, exiting early if an error occurred.
         match formatter::check(&folder) {
             // Merge new unformatted files into existing unformatted files.
             Ok(mut unformatted) => unformatted_files.append(&mut unformatted),
             Err(error) => {
+                if is_ci {
+                    // End group if an error occurred, so it is not hidden.
+                    println!("::endgroup::");
+                }
+
                 eprintln!("Error: {}", error);
 
                 return ExitCode::FAILURE;
             }
         }
+
+        if is_ci {
+            println!("::endgroup::");
+        }
     }
 
     if !unformatted_files.is_empty() {
-        eprintln!("\nThe following files are not formatted:");
+        println!("\nThe following files are not formatted:");
 
         for path in unformatted_files {
-            eprintln!("- {:?}", path);
+            if is_ci {
+                // Print custom error message, formatted in Github Actions.
+                // https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-error-message
+                println!("::error file={0:?},title=File is not formatted with correct hide-lines annotations::- {0:?}", path);
+            } else {
+                println!("- {:?}", path);
+            }
         }
 
+        println!("\nRun write_rustdoc_hide_lines.sh to automatically fix these errors.");
+
         ExitCode::FAILURE
     } else {
         println!("All files are properly formatted. :)");