output error messages in linter

Currenty error messages are hidden in logs and hard to find. Let's clearly print them at the end instead, so it's clear what needs fixing

Change-Id: Ica875d7b8a1bfd02149f086767fbe6c6d0eb15e4

linter/main.rs

@@ -42,16 +42,16 @@ struct LinterContext {
     verbose: bool,
 }
 
-#[derive(Copy, Clone, Debug, Default)]
+#[derive(Clone, Debug, Default)]
 struct ResultCounts {
     processed: usize,
-    failures: usize,
+    error_messages: Vec<String>,
 }
 
 impl std::ops::AddAssign<ResultCounts> for ResultCounts {
     fn add_assign(&mut self, rhs: ResultCounts) {
         self.processed += rhs.processed;
-        self.failures += rhs.failures;
+        self.error_messages.extend(rhs.error_messages);
     }
 }
 
@@ -84,8 +84,11 @@ fn main() {
     let elapsed = end.duration_since(start);
     println!("\n\nProcessed {} files in {:?}", counts.processed, elapsed);
 
-    if counts.failures > 0 {
-        println!("{}", format!("Files with issues: {}", counts.failures).red());
+    if !counts.error_messages.is_empty() {
+        println!("{}", format!("Files with issues: {}", counts.error_messages.len()).red());
+        for message in counts.error_messages {
+            println!("{}", message.red());
+        }
         std::process::exit(1);
     } else {
         println!("{}", "No files with issues found".cyan());
@@ -112,12 +115,13 @@ impl LinterContext {
         let linter = Linter::new(tool);
         let outcomes = linter.lint_files(&self.walk_builder, self.mode);
         let processed = outcomes.len();
-        let mut failures = 0;
+        let mut error_messages = Vec::new();
         for outcome in outcomes {
             match outcome.outcome {
                 Err(err) => {
                     let message = format!("TOOL FAILURE {err:?}").red();
                     println!("{}", message);
+                    error_messages.push(format!("{}: {}", outcome.filename, message));
                 }
                 Ok(linter::Outcome::Success(message)) => {
                     if !message.is_empty() {
@@ -128,8 +132,8 @@ impl LinterContext {
                     }
                 }
                 Ok(linter::Outcome::Failure(message)) => {
-                    failures += 1;
-                    println!("{}\n{message}", outcome.filename.red())
+                    println!("{}\n{message}", outcome.filename.red());
+                    error_messages.push(format!("{}: {}", outcome.filename, message));
                 }
             };
         }
@@ -141,6 +145,6 @@ impl LinterContext {
             processed,
             elapsed
         );
-        ResultCounts { processed, failures }
+        ResultCounts { processed, error_messages }
     }
 }