fix: correctly classify compiler warnings

Author: shaikhu

src/main/java/scala_maven_executions/LogProcessorUtils.java

@@ -4,6 +4,8 @@
  */
 package scala_maven_executions;
 
+import java.util.regex.Pattern;
+
 public class LogProcessorUtils {
 
   public enum Level {
@@ -17,16 +19,24 @@ public static class LevelState {
     public String untilContains = null;
   }
 
+  /**
+   * Matches "warning" or "warnings" as complete words, but not filenames e.g. "Warnings.scala".
+   */
+  private static final Pattern WARNING_WORD = Pattern.compile("\\bwarnings?\\b(?!\\.scala)");
+
+  /** Matches "error" or "errors" as complete words, but not filenames e.g. "Errors.scala". */
+  private static final Pattern ERROR_WORD = Pattern.compile("\\berrors?\\b(?!\\.scala)");
+
   public static LevelState levelStateOf(String line, LevelState previous) {
     LevelState back = new LevelState();
     String lineLowerCase = line.toLowerCase();
-    if (lineLowerCase.contains("error")) {
-      back.level = Level.ERROR;
+    if (isWarningLine(lineLowerCase)) {
+      back.level = Level.WARNING;
       if (lineLowerCase.contains(".scala")) {
         back.untilContains = "^";
       }
-    } else if (lineLowerCase.contains("warn")) {
-      back.level = Level.WARNING;
+    } else if (isErrorLine(lineLowerCase)) {
+      back.level = Level.ERROR;
       if (lineLowerCase.contains(".scala")) {
         back.untilContains = "^";
       }
@@ -40,4 +50,30 @@ public static LevelState levelStateOf(String line, LevelState previous) {
     }
     return back;
   }
+
+  private static boolean isWarningLine(String line) {
+    return hasSeverityMarker(line, "warning") || WARNING_WORD.matcher(line).find();
+  }
+
+  private static boolean isErrorLine(String line) {
+    return hasSeverityMarker(line, "error") || ERROR_WORD.matcher(line).find();
+  }
+
+  /**
+   * Checks whether the line contains a severity marker e.g. "error:" or "warning:".
+   *
+   * <p>Matches common compiler and build-tool formats, including:
+   *
+   * <ul>
+   *   <li>{@code path:lineNum: error: message}
+   *   <li>{@code error: message} at the start of the line
+   * </ul>
+   *
+   * @param lineLowerCase the lowercase line to check
+   * @param marker the severity marker to look for e.g. "error" or "warning"
+   * @return true if the line starts with {@code marker:} or contains {@code " marker:"}
+   */
+  private static boolean hasSeverityMarker(String lineLowerCase, String marker) {
+    return lineLowerCase.startsWith(marker + ":") || lineLowerCase.contains(" " + marker + ":");
+  }
 }

src/test/java/scala_maven/LogProcessorUtilsTest.java

@@ -68,6 +68,25 @@ public void jdkSplit() throws Exception {
             null);
   }
 
+  @Test
+  public void severityDeterminedByMarkerNotFilenameOrTextContent() throws Exception {
+    LevelState previous = new LevelState();
+    previous =
+        assertLevelState(
+            "/path/to/Errors.scala:88: warning: match may not be exhaustive.",
+            previous,
+            Level.WARNING,
+            "^");
+    previous =
+        assertLevelState("/path/to/Warning.scala:12: error: boom", previous, Level.ERROR, "^");
+    previous =
+        assertLevelState(
+            "/path/to/FooBar.scala:3657: warning: a type was inferred to be `Any`; this may indicate a programming error.",
+            previous,
+            Level.WARNING,
+            "^");
+  }
+
   private LevelState assertLevelState(
       String input, LevelState previous, Level expectedLevel, String expectedUntilContains) {
     LevelState back = LogProcessorUtils.levelStateOf(input, previous);