fix(LineLengthChecker): do not crash if files contain invalid UTF-8 c…

…haracters (#23)

Closes #22

src/main/java/de/uni_passau/fim/se2/pipeline_helper/Main.java

@@ -113,10 +113,20 @@ public Integer call() throws Exception {
             validateParams();
 
             final Checker checker = buildChecker();
-            final CheckerResult result = checker.check();
-            CheckerResultWriter.writeFeedback(parent.outputDirectory, result);
+            CheckerResult result;
+            try {
+                result = checker.check();
+                System.out.println("Successfully produced a checker result.");
+            }
+            catch (Exception e) {
+                e.printStackTrace();
+                result = new CheckerResult(
+                    "Error", false,
+                    "The checker crashed. Please contact your instructor to resolve the issue."
+                );
+            }
 
-            System.out.println("Successfully produced a checker result.");
+            CheckerResultWriter.writeFeedback(parent.outputDirectory, result);
 
             return 0;
         }

src/main/java/de/uni_passau/fim/se2/pipeline_helper/checkers/line_length/LineLengthChecker.java

@@ -5,6 +5,7 @@
 package de.uni_passau.fim.se2.pipeline_helper.checkers.line_length;
 
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.*;
@@ -36,7 +37,13 @@ public CheckerResult check() throws CheckerException {
         final List<FileLineLengthViolations> violations = new ArrayList<>();
         for (Iterator<Path> it = files.iterator(); it.hasNext();) {
             final Path p = it.next();
-            final SortedMap<Integer, Integer> linesWithViolations = getAllViolationsWithLength(p);
+            final SortedMap<Integer, Integer> linesWithViolations;
+            try {
+                linesWithViolations = getAllViolationsWithLength(p);
+            }
+            catch (CheckerException e) {
+                return new CheckerResult(CHECKER_NAME, false, e.getMessage());
+            }
             if (!linesWithViolations.isEmpty()) {
                 violations.add(new FileLineLengthViolations(directory.relativize(p), linesWithViolations));
             }
@@ -57,7 +64,7 @@ private SortedMap<Integer, Integer> getAllViolationsWithLength(final Path path)
         try (Stream<String> lines = Files.lines(path)) {
             return getAllViolationWithLength(lines);
         }
-        catch (IOException e) {
+        catch (IOException | UncheckedIOException e) {
             throw new CheckerException("Cannot read file " + path, e);
         }
     }

src/test/java/de/uni_passau/fim/se2/pipeline_helper/checkers/LineLengthCheckerTest.java

@@ -7,7 +7,6 @@
 import static com.google.common.truth.Truth.assertThat;
 import static de.uni_passau.fim.se2.pipeline_helper.TestUtil.resource;
 
-import java.io.File;
 import java.net.URISyntaxException;
 import java.nio.file.Path;
 
@@ -29,65 +28,57 @@ static void init() throws URISyntaxException {
 
     @Test
     void checkFailedSingleViolation() throws Exception {
+        Path invalidDir = dir.resolve("invalid/");
         final LineLengthChecker checker = new LineLengthChecker(
-            dir, FilteredFilesStream.files(dir, "java"), 80
+            invalidDir, FilteredFilesStream.files(invalidDir, "java"), 80
         );
         final CheckerResult result = checker.check();
         assertThat(result.getName()).contains("LineLengthChecker");
         assertThat(result.isSuccessful()).isFalse();
         assertThat(result.getMessage()).contains(
             withNormalisedNewline(
                 """
-                    invalid%sInvalidFileSingleViolation.java, on 1 line:
-                        -> line 7, length 82""".formatted(File.separator)
+                    InvalidFileSingleViolation.java, on 1 line:
+                        -> line 7, length 82"""
             )
         );
     }
 
     @Test
-    void checkFailedTwoViolationsDifferentFiles() throws Exception {
+    void checkFailedDifferentFiles() throws Exception {
+        Path invalidDir = dir.resolve("invalid/");
         final LineLengthChecker checker = new LineLengthChecker(
-            dir, FilteredFilesStream.files(dir, "java"), 80
+            invalidDir, FilteredFilesStream.files(invalidDir, "java"), 80
         );
         final CheckerResult result = checker.check();
         assertThat(result.getName()).contains("LineLengthChecker");
         assertThat(result.isSuccessful()).isFalse();
         assertThat(result.getMessage()).contains(
             withNormalisedNewline(
                 """
-                    invalid%sInvalidFile.java, on 2 lines:
+                    InvalidFile.java, on 2 lines:
                         -> line 7, length 82
-                        -> line 10, length 99""".formatted(File.separator)
+                        -> line 10, length 99"""
             )
         );
-        assertThat(result.getMessage()).contains(
-            withNormalisedNewline(
-                """
-                    also_invalid%sInvalidFile.java, on 2 lines:
-                        -> line 7, length 82
-                        -> line 10, length 99""".formatted(File.separator)
-            )
+        withNormalisedNewline(
+            """
+                invalidFileSingleViolation.java, on 1 line:
+                    -> line 7, length 82"""
         );
     }
 
     @Test
-    void checkFailedMoreThanTwoViolations() throws Exception {
+    void checkFailedIllegalByteSequence() throws Exception {
+        Path illegalByteSeqDir = dir.resolve("illegal_byte_sequence/");
         final LineLengthChecker checker = new LineLengthChecker(
-            dir, FilteredFilesStream.files(dir, "java"), 80
+            illegalByteSeqDir, FilteredFilesStream.files(illegalByteSeqDir, "java"), 80
         );
         final CheckerResult result = checker.check();
         assertThat(result.getName()).contains("LineLengthChecker");
         assertThat(result.isSuccessful()).isFalse();
-        assertThat(result.getMessage()).contains(
-            withNormalisedNewline(
-                """
-                    invalid%sInvalidFileFourViolations.java, on 4 lines:
-                        -> line 7, length 82
-                        -> line 8, length 82
-                        -> line 9, length 82
-                        -> line 10, length 82""".formatted(File.separator)
-            )
-        );
+        assertThat(result.getMessage()).startsWith("Cannot read file ");
+        assertThat(result.getMessage()).endsWith("InvalidByteSequence.java");
     }
 
     @Test

src/test/resources/line_length_checker_demo_files/illegal_byte_sequence/InvalidByteSequence.java

@@ -0,0 +1,5 @@
+// SPDX-FileCopyrightText: 2022 Pipeline Helper Contributors
+//
+// SPDX-License-Identifier: EUPL-1.2
+
+Ã(